)first).compareTo(second);
+ }
+ static final NaturalOrder INSTANCE = new NaturalOrder();
+ }
+
+ /**
+ * Checks that {@code fromIndex} and {@code toIndex} are in
+ * the range and throws an exception if they aren't.
+ */
+ private static void rangeCheck(int arrayLength, int fromIndex, int toIndex) {
+ if (fromIndex > toIndex) {
+ throw new IllegalArgumentException(
+ "fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
+ }
+ if (fromIndex < 0) {
+ throw new ArrayIndexOutOfBoundsException(fromIndex);
+ }
+ if (toIndex > arrayLength) {
+ throw new ArrayIndexOutOfBoundsException(toIndex);
+ }
+ }
+
+ /*
+ * Sorting methods. Note that all public "sort" methods take the
+ * same form: Performing argument checks if necessary, and then
+ * expanding arguments into those required for the internal
+ * implementation methods residing in other package-private
+ * classes (except for legacyMergeSort, included in this class).
+ */
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(int[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(int[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(long[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(long[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(short[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(short[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(char[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(char[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(byte[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(byte[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
The {@code <} relation does not provide a total order on all float
+ * values: {@code -0.0f == 0.0f} is {@code true} and a {@code Float.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
+ * {@code 0.0f} and {@code Float.NaN} is considered greater than any
+ * other value and all {@code Float.NaN} values are considered equal.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(float[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
The {@code <} relation does not provide a total order on all float
+ * values: {@code -0.0f == 0.0f} is {@code true} and a {@code Float.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
+ * {@code 0.0f} and {@code Float.NaN} is considered greater than any
+ * other value and all {@code Float.NaN} values are considered equal.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(float[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
The {@code <} relation does not provide a total order on all double
+ * values: {@code -0.0d == 0.0d} is {@code true} and a {@code Double.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
+ * {@code 0.0d} and {@code Double.NaN} is considered greater than any
+ * other value and all {@code Double.NaN} values are considered equal.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ */
+ public static void sort(double[] a) {
+ DualPivotQuicksort.sort(a, 0, a.length - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending order. The range
+ * to be sorted extends from the index {@code fromIndex}, inclusive, to
+ * the index {@code toIndex}, exclusive. If {@code fromIndex == toIndex},
+ * the range to be sorted is empty.
+ *
+ *
The {@code <} relation does not provide a total order on all double
+ * values: {@code -0.0d == 0.0d} is {@code true} and a {@code Double.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
+ * {@code 0.0d} and {@code Double.NaN} is considered greater than any
+ * other value and all {@code Double.NaN} values are considered equal.
+ *
+ *
Implementation note: The sorting algorithm is a Dual-Pivot Quicksort
+ * by Vladimir Yaroslavskiy, Jon Bentley, and Joshua Bloch. This algorithm
+ * offers O(n log(n)) performance on many data sets that cause other
+ * quicksorts to degrade to quadratic performance, and is typically
+ * faster than traditional (one-pivot) Quicksort implementations.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ */
+ public static void sort(double[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(byte[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(byte[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(byte[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1);
+ else
+ new ArraysParallelSortHelpers.FJByte.Sorter
+ (null, a, new byte[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(byte[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(byte[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(byte[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1);
+ else
+ new ArraysParallelSortHelpers.FJByte.Sorter
+ (null, a, new byte[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(char[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(char[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(char[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJChar.Sorter
+ (null, a, new char[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(char[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(char[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(char[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJChar.Sorter
+ (null, a, new char[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(short[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(short[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(short[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJShort.Sorter
+ (null, a, new short[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(short[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(short[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(short[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJShort.Sorter
+ (null, a, new short[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(int[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(int[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(int[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJInt.Sorter
+ (null, a, new int[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(int[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(int[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(int[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJInt.Sorter
+ (null, a, new int[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(long[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(long[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(long[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJLong.Sorter
+ (null, a, new long[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(long[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(long[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(long[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJLong.Sorter
+ (null, a, new long[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
The {@code <} relation does not provide a total order on all float
+ * values: {@code -0.0f == 0.0f} is {@code true} and a {@code Float.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
+ * {@code 0.0f} and {@code Float.NaN} is considered greater than any
+ * other value and all {@code Float.NaN} values are considered equal.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(float[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(float[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(float[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJFloat.Sorter
+ (null, a, new float[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ *
The {@code <} relation does not provide a total order on all float
+ * values: {@code -0.0f == 0.0f} is {@code true} and a {@code Float.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Float#compareTo}: {@code -0.0f} is treated as less than value
+ * {@code 0.0f} and {@code Float.NaN} is considered greater than any
+ * other value and all {@code Float.NaN} values are considered equal.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(float[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(float[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(float[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJFloat.Sorter
+ (null, a, new float[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array into ascending numerical order.
+ *
+ *
The {@code <} relation does not provide a total order on all double
+ * values: {@code -0.0d == 0.0d} is {@code true} and a {@code Double.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
+ * {@code 0.0d} and {@code Double.NaN} is considered greater than any
+ * other value and all {@code Double.NaN} values are considered equal.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(double[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(double[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(double[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, 0, n - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJDouble.Sorter
+ (null, a, new double[n], 0, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the array into ascending numerical order.
+ * The range to be sorted extends from the index {@code fromIndex},
+ * inclusive, to the index {@code toIndex}, exclusive. If
+ * {@code fromIndex == toIndex}, the range to be sorted is empty.
+ *
+ *
The {@code <} relation does not provide a total order on all double
+ * values: {@code -0.0d == 0.0d} is {@code true} and a {@code Double.NaN}
+ * value compares neither less than, greater than, nor equal to any value,
+ * even itself. This method uses the total order imposed by the method
+ * {@link Double#compareTo}: {@code -0.0d} is treated as less than value
+ * {@code 0.0d} and {@code Double.NaN} is considered greater than any
+ * other value and all {@code Double.NaN} values are considered equal.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(double[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(double[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element, inclusive, to be sorted
+ * @param toIndex the index of the last element, exclusive, to be sorted
+ *
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > a.length}
+ *
+ * @since 1.8
+ */
+ public static void parallelSort(double[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ DualPivotQuicksort.sort(a, fromIndex, toIndex - 1, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJDouble.Sorter
+ (null, a, new double[n], fromIndex, n, 0,
+ ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g).invoke();
+ }
+
+ /**
+ * Sorts the specified array of objects into ascending order, according
+ * to the {@linkplain Comparable natural ordering} of its elements.
+ * All elements in the array must implement the {@link Comparable}
+ * interface. Furthermore, all elements in the array must be
+ * mutually comparable (that is, {@code e1.compareTo(e2)} must
+ * not throw a {@code ClassCastException} for any elements {@code e1}
+ * and {@code e2} in the array).
+ *
+ *
This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(Object[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(Object[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ *
+ * @throws ClassCastException if the array contains elements that are not
+ * mutually comparable (for example, strings and integers)
+ * @throws IllegalArgumentException (optional) if the natural
+ * ordering of the array elements is found to violate the
+ * {@link Comparable} contract
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static > void parallelSort(T[] a) {
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ TimSort.sort(a, 0, n, NaturalOrder.INSTANCE, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJObject.Sorter<>
+ (null, a,
+ (T[])Array.newInstance(a.getClass().getComponentType(), n),
+ 0, n, 0, ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g, NaturalOrder.INSTANCE).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the specified array of objects into
+ * ascending order, according to the
+ * {@linkplain Comparable natural ordering} of its
+ * elements. The range to be sorted extends from index
+ * {@code fromIndex}, inclusive, to index {@code toIndex}, exclusive.
+ * (If {@code fromIndex==toIndex}, the range to be sorted is empty.) All
+ * elements in this range must implement the {@link Comparable}
+ * interface. Furthermore, all elements in this range must be mutually
+ * comparable (that is, {@code e1.compareTo(e2)} must not throw a
+ * {@code ClassCastException} for any elements {@code e1} and
+ * {@code e2} in the array).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(Object[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(Object[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element (inclusive) to be
+ * sorted
+ * @param toIndex the index of the last element (exclusive) to be sorted
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex} or
+ * (optional) if the natural ordering of the array elements is
+ * found to violate the {@link Comparable} contract
+ * @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
+ * {@code toIndex > a.length}
+ * @throws ClassCastException if the array contains elements that are
+ * not mutually comparable (for example, strings and
+ * integers).
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static >
+ void parallelSort(T[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ TimSort.sort(a, fromIndex, toIndex, NaturalOrder.INSTANCE, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJObject.Sorter<>
+ (null, a,
+ (T[])Array.newInstance(a.getClass().getComponentType(), n),
+ fromIndex, n, 0, ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g, NaturalOrder.INSTANCE).invoke();
+ }
+
+ /**
+ * Sorts the specified array of objects according to the order induced by
+ * the specified comparator. All elements in the array must be
+ * mutually comparable by the specified comparator (that is,
+ * {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
+ * for any elements {@code e1} and {@code e2} in the array).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(Object[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(Object[]) Arrays.sort} method. The algorithm requires a
+ * working space no greater than the size of the original array. The
+ * {@link ForkJoinPool#commonPool() ForkJoin common pool} is used to
+ * execute any parallel tasks.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ * @param cmp the comparator to determine the order of the array. A
+ * {@code null} value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @throws ClassCastException if the array contains elements that are
+ * not mutually comparable using the specified comparator
+ * @throws IllegalArgumentException (optional) if the comparator is
+ * found to violate the {@link java.util.Comparator} contract
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static void parallelSort(T[] a, Comparator cmp) {
+ if (cmp == null)
+ cmp = NaturalOrder.INSTANCE;
+ int n = a.length, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ TimSort.sort(a, 0, n, cmp, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJObject.Sorter<>
+ (null, a,
+ (T[])Array.newInstance(a.getClass().getComponentType(), n),
+ 0, n, 0, ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g, cmp).invoke();
+ }
+
+ /**
+ * Sorts the specified range of the specified array of objects according
+ * to the order induced by the specified comparator. The range to be
+ * sorted extends from index {@code fromIndex}, inclusive, to index
+ * {@code toIndex}, exclusive. (If {@code fromIndex==toIndex}, the
+ * range to be sorted is empty.) All elements in the range must be
+ * mutually comparable by the specified comparator (that is,
+ * {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
+ * for any elements {@code e1} and {@code e2} in the range).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ * @implNote The sorting algorithm is a parallel sort-merge that breaks the
+ * array into sub-arrays that are themselves sorted and then merged. When
+ * the sub-array length reaches a minimum granularity, the sub-array is
+ * sorted using the appropriate {@link Arrays#sort(Object[]) Arrays.sort}
+ * method. If the length of the specified array is less than the minimum
+ * granularity, then it is sorted using the appropriate {@link
+ * Arrays#sort(Object[]) Arrays.sort} method. The algorithm requires a working
+ * space no greater than the size of the specified range of the original
+ * array. The {@link ForkJoinPool#commonPool() ForkJoin common pool} is
+ * used to execute any parallel tasks.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element (inclusive) to be
+ * sorted
+ * @param toIndex the index of the last element (exclusive) to be sorted
+ * @param cmp the comparator to determine the order of the array. A
+ * {@code null} value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex} or
+ * (optional) if the natural ordering of the array elements is
+ * found to violate the {@link Comparable} contract
+ * @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
+ * {@code toIndex > a.length}
+ * @throws ClassCastException if the array contains elements that are
+ * not mutually comparable (for example, strings and
+ * integers).
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static void parallelSort(T[] a, int fromIndex, int toIndex,
+ Comparator cmp) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ if (cmp == null)
+ cmp = NaturalOrder.INSTANCE;
+ int n = toIndex - fromIndex, p, g;
+ if (n <= MIN_ARRAY_SORT_GRAN ||
+ (p = ForkJoinPool.getCommonPoolParallelism()) == 1)
+ TimSort.sort(a, fromIndex, toIndex, cmp, null, 0, 0);
+ else
+ new ArraysParallelSortHelpers.FJObject.Sorter<>
+ (null, a,
+ (T[])Array.newInstance(a.getClass().getComponentType(), n),
+ fromIndex, n, 0, ((g = n / (p << 2)) <= MIN_ARRAY_SORT_GRAN) ?
+ MIN_ARRAY_SORT_GRAN : g, cmp).invoke();
+ }
+
+ /*
+ * Sorting of complex type arrays.
+ */
+
+ /**
+ * Old merge sort implementation can be selected (for
+ * compatibility with broken comparators) using a system property.
+ * Cannot be a static boolean in the enclosing class due to
+ * circular dependencies. To be removed in a future release.
+ */
+ static final class LegacyMergeSort {
+ private static final boolean userRequested =
+ java.security.AccessController.doPrivileged(
+ new sun.security.action.GetBooleanAction(
+ "java.util.Arrays.useLegacyMergeSort")).booleanValue();
+ }
+
+ /**
+ * Sorts the specified array of objects into ascending order, according
+ * to the {@linkplain Comparable natural ordering} of its elements.
+ * All elements in the array must implement the {@link Comparable}
+ * interface. Furthermore, all elements in the array must be
+ * mutually comparable (that is, {@code e1.compareTo(e2)} must
+ * not throw a {@code ClassCastException} for any elements {@code e1}
+ * and {@code e2} in the array).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ *
Implementation note: This implementation is a stable, adaptive,
+ * iterative mergesort that requires far fewer than n lg(n) comparisons
+ * when the input array is partially sorted, while offering the
+ * performance of a traditional mergesort when the input array is
+ * randomly ordered. If the input array is nearly sorted, the
+ * implementation requires approximately n comparisons. Temporary
+ * storage requirements vary from a small constant for nearly sorted
+ * input arrays to n/2 object references for randomly ordered input
+ * arrays.
+ *
+ *
The implementation takes equal advantage of ascending and
+ * descending order in its input array, and can take advantage of
+ * ascending and descending order in different parts of the the same
+ * input array. It is well-suited to merging two or more sorted arrays:
+ * simply concatenate the arrays and sort the resulting array.
+ *
+ *
The implementation was adapted from Tim Peters's list sort for Python
+ * (
+ * TimSort ). It uses techniques from Peter McIlroy's "Optimistic
+ * Sorting and Information Theoretic Complexity", in Proceedings of the
+ * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
+ * January 1993.
+ *
+ * @param a the array to be sorted
+ * @throws ClassCastException if the array contains elements that are not
+ * mutually comparable (for example, strings and integers)
+ * @throws IllegalArgumentException (optional) if the natural
+ * ordering of the array elements is found to violate the
+ * {@link Comparable} contract
+ */
+ public static void sort(Object[] a) {
+ if (LegacyMergeSort.userRequested)
+ legacyMergeSort(a);
+ else
+ ComparableTimSort.sort(a, 0, a.length, null, 0, 0);
+ }
+
+ /** To be removed in a future release. */
+ private static void legacyMergeSort(Object[] a) {
+ Object[] aux = a.clone();
+ mergeSort(aux, a, 0, a.length, 0);
+ }
+
+ /**
+ * Sorts the specified range of the specified array of objects into
+ * ascending order, according to the
+ * {@linkplain Comparable natural ordering} of its
+ * elements. The range to be sorted extends from index
+ * {@code fromIndex}, inclusive, to index {@code toIndex}, exclusive.
+ * (If {@code fromIndex==toIndex}, the range to be sorted is empty.) All
+ * elements in this range must implement the {@link Comparable}
+ * interface. Furthermore, all elements in this range must be mutually
+ * comparable (that is, {@code e1.compareTo(e2)} must not throw a
+ * {@code ClassCastException} for any elements {@code e1} and
+ * {@code e2} in the array).
+ *
+ *
This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ *
Implementation note: This implementation is a stable, adaptive,
+ * iterative mergesort that requires far fewer than n lg(n) comparisons
+ * when the input array is partially sorted, while offering the
+ * performance of a traditional mergesort when the input array is
+ * randomly ordered. If the input array is nearly sorted, the
+ * implementation requires approximately n comparisons. Temporary
+ * storage requirements vary from a small constant for nearly sorted
+ * input arrays to n/2 object references for randomly ordered input
+ * arrays.
+ *
+ *
The implementation takes equal advantage of ascending and
+ * descending order in its input array, and can take advantage of
+ * ascending and descending order in different parts of the the same
+ * input array. It is well-suited to merging two or more sorted arrays:
+ * simply concatenate the arrays and sort the resulting array.
+ *
+ *
The implementation was adapted from Tim Peters's list sort for Python
+ * (
+ * TimSort ). It uses techniques from Peter McIlroy's "Optimistic
+ * Sorting and Information Theoretic Complexity", in Proceedings of the
+ * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
+ * January 1993.
+ *
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element (inclusive) to be
+ * sorted
+ * @param toIndex the index of the last element (exclusive) to be sorted
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex} or
+ * (optional) if the natural ordering of the array elements is
+ * found to violate the {@link Comparable} contract
+ * @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
+ * {@code toIndex > a.length}
+ * @throws ClassCastException if the array contains elements that are
+ * not mutually comparable (for example, strings and
+ * integers).
+ */
+ public static void sort(Object[] a, int fromIndex, int toIndex) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ if (LegacyMergeSort.userRequested)
+ legacyMergeSort(a, fromIndex, toIndex);
+ else
+ ComparableTimSort.sort(a, fromIndex, toIndex, null, 0, 0);
+ }
+
+ /** To be removed in a future release. */
+ private static void legacyMergeSort(Object[] a,
+ int fromIndex, int toIndex) {
+ Object[] aux = copyOfRange(a, fromIndex, toIndex);
+ mergeSort(aux, a, fromIndex, toIndex, -fromIndex);
+ }
+
+ /**
+ * Tuning parameter: list size at or below which insertion sort will be
+ * used in preference to mergesort.
+ * To be removed in a future release.
+ */
+ private static final int INSERTIONSORT_THRESHOLD = 7;
+
+ /**
+ * Src is the source array that starts at index 0
+ * Dest is the (possibly larger) array destination with a possible offset
+ * low is the index in dest to start sorting
+ * high is the end index in dest to end sorting
+ * off is the offset to generate corresponding low, high in src
+ * To be removed in a future release.
+ */
+ @SuppressWarnings({"unchecked", "rawtypes"})
+ private static void mergeSort(Object[] src,
+ Object[] dest,
+ int low,
+ int high,
+ int off) {
+ int length = high - low;
+
+ // Insertion sort on smallest arrays
+ if (length < INSERTIONSORT_THRESHOLD) {
+ for (int i=low; ilow &&
+ ((Comparable) dest[j-1]).compareTo(dest[j])>0; j--)
+ swap(dest, j, j-1);
+ return;
+ }
+
+ // Recursively sort halves of dest into src
+ int destLow = low;
+ int destHigh = high;
+ low += off;
+ high += off;
+ int mid = (low + high) >>> 1;
+ mergeSort(dest, src, low, mid, -off);
+ mergeSort(dest, src, mid, high, -off);
+
+ // If list is already sorted, just copy from src to dest. This is an
+ // optimization that results in faster sorts for nearly ordered lists.
+ if (((Comparable)src[mid-1]).compareTo(src[mid]) <= 0) {
+ System.arraycopy(src, low, dest, destLow, length);
+ return;
+ }
+
+ // Merge sorted halves (now in src) into dest
+ for(int i = destLow, p = low, q = mid; i < destHigh; i++) {
+ if (q >= high || p < mid && ((Comparable)src[p]).compareTo(src[q])<=0)
+ dest[i] = src[p++];
+ else
+ dest[i] = src[q++];
+ }
+ }
+
+ /**
+ * Swaps x[a] with x[b].
+ */
+ private static void swap(Object[] x, int a, int b) {
+ Object t = x[a];
+ x[a] = x[b];
+ x[b] = t;
+ }
+
+ /**
+ * Sorts the specified array of objects according to the order induced by
+ * the specified comparator. All elements in the array must be
+ * mutually comparable by the specified comparator (that is,
+ * {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
+ * for any elements {@code e1} and {@code e2} in the array).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ *
Implementation note: This implementation is a stable, adaptive,
+ * iterative mergesort that requires far fewer than n lg(n) comparisons
+ * when the input array is partially sorted, while offering the
+ * performance of a traditional mergesort when the input array is
+ * randomly ordered. If the input array is nearly sorted, the
+ * implementation requires approximately n comparisons. Temporary
+ * storage requirements vary from a small constant for nearly sorted
+ * input arrays to n/2 object references for randomly ordered input
+ * arrays.
+ *
+ *
The implementation takes equal advantage of ascending and
+ * descending order in its input array, and can take advantage of
+ * ascending and descending order in different parts of the the same
+ * input array. It is well-suited to merging two or more sorted arrays:
+ * simply concatenate the arrays and sort the resulting array.
+ *
+ *
The implementation was adapted from Tim Peters's list sort for Python
+ * (
+ * TimSort ). It uses techniques from Peter McIlroy's "Optimistic
+ * Sorting and Information Theoretic Complexity", in Proceedings of the
+ * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
+ * January 1993.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ * @param c the comparator to determine the order of the array. A
+ * {@code null} value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @throws ClassCastException if the array contains elements that are
+ * not mutually comparable using the specified comparator
+ * @throws IllegalArgumentException (optional) if the comparator is
+ * found to violate the {@link Comparator} contract
+ */
+ public static void sort(T[] a, Comparator c) {
+ if (c == null) {
+ sort(a);
+ } else {
+ if (LegacyMergeSort.userRequested)
+ legacyMergeSort(a, c);
+ else
+ TimSort.sort(a, 0, a.length, c, null, 0, 0);
+ }
+ }
+
+ /** To be removed in a future release. */
+ private static void legacyMergeSort(T[] a, Comparator c) {
+ T[] aux = a.clone();
+ if (c==null)
+ mergeSort(aux, a, 0, a.length, 0);
+ else
+ mergeSort(aux, a, 0, a.length, 0, c);
+ }
+
+ /**
+ * Sorts the specified range of the specified array of objects according
+ * to the order induced by the specified comparator. The range to be
+ * sorted extends from index {@code fromIndex}, inclusive, to index
+ * {@code toIndex}, exclusive. (If {@code fromIndex==toIndex}, the
+ * range to be sorted is empty.) All elements in the range must be
+ * mutually comparable by the specified comparator (that is,
+ * {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
+ * for any elements {@code e1} and {@code e2} in the range).
+ *
+ * This sort is guaranteed to be stable : equal elements will
+ * not be reordered as a result of the sort.
+ *
+ *
Implementation note: This implementation is a stable, adaptive,
+ * iterative mergesort that requires far fewer than n lg(n) comparisons
+ * when the input array is partially sorted, while offering the
+ * performance of a traditional mergesort when the input array is
+ * randomly ordered. If the input array is nearly sorted, the
+ * implementation requires approximately n comparisons. Temporary
+ * storage requirements vary from a small constant for nearly sorted
+ * input arrays to n/2 object references for randomly ordered input
+ * arrays.
+ *
+ *
The implementation takes equal advantage of ascending and
+ * descending order in its input array, and can take advantage of
+ * ascending and descending order in different parts of the the same
+ * input array. It is well-suited to merging two or more sorted arrays:
+ * simply concatenate the arrays and sort the resulting array.
+ *
+ *
The implementation was adapted from Tim Peters's list sort for Python
+ * (
+ * TimSort ). It uses techniques from Peter McIlroy's "Optimistic
+ * Sorting and Information Theoretic Complexity", in Proceedings of the
+ * Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
+ * January 1993.
+ *
+ * @param the class of the objects to be sorted
+ * @param a the array to be sorted
+ * @param fromIndex the index of the first element (inclusive) to be
+ * sorted
+ * @param toIndex the index of the last element (exclusive) to be sorted
+ * @param c the comparator to determine the order of the array. A
+ * {@code null} value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @throws ClassCastException if the array contains elements that are not
+ * mutually comparable using the specified comparator.
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex} or
+ * (optional) if the comparator is found to violate the
+ * {@link Comparator} contract
+ * @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
+ * {@code toIndex > a.length}
+ */
+ public static void sort(T[] a, int fromIndex, int toIndex,
+ Comparator c) {
+ if (c == null) {
+ sort(a, fromIndex, toIndex);
+ } else {
+ rangeCheck(a.length, fromIndex, toIndex);
+ if (LegacyMergeSort.userRequested)
+ legacyMergeSort(a, fromIndex, toIndex, c);
+ else
+ TimSort.sort(a, fromIndex, toIndex, c, null, 0, 0);
+ }
+ }
+
+ /** To be removed in a future release. */
+ private static void legacyMergeSort(T[] a, int fromIndex, int toIndex,
+ Comparator c) {
+ T[] aux = copyOfRange(a, fromIndex, toIndex);
+ if (c==null)
+ mergeSort(aux, a, fromIndex, toIndex, -fromIndex);
+ else
+ mergeSort(aux, a, fromIndex, toIndex, -fromIndex, c);
+ }
+
+ /**
+ * Src is the source array that starts at index 0
+ * Dest is the (possibly larger) array destination with a possible offset
+ * low is the index in dest to start sorting
+ * high is the end index in dest to end sorting
+ * off is the offset into src corresponding to low in dest
+ * To be removed in a future release.
+ */
+ @SuppressWarnings({"rawtypes", "unchecked"})
+ private static void mergeSort(Object[] src,
+ Object[] dest,
+ int low, int high, int off,
+ Comparator c) {
+ int length = high - low;
+
+ // Insertion sort on smallest arrays
+ if (length < INSERTIONSORT_THRESHOLD) {
+ for (int i=low; ilow && c.compare(dest[j-1], dest[j])>0; j--)
+ swap(dest, j, j-1);
+ return;
+ }
+
+ // Recursively sort halves of dest into src
+ int destLow = low;
+ int destHigh = high;
+ low += off;
+ high += off;
+ int mid = (low + high) >>> 1;
+ mergeSort(dest, src, low, mid, -off, c);
+ mergeSort(dest, src, mid, high, -off, c);
+
+ // If list is already sorted, just copy from src to dest. This is an
+ // optimization that results in faster sorts for nearly ordered lists.
+ if (c.compare(src[mid-1], src[mid]) <= 0) {
+ System.arraycopy(src, low, dest, destLow, length);
+ return;
+ }
+
+ // Merge sorted halves (now in src) into dest
+ for(int i = destLow, p = low, q = mid; i < destHigh; i++) {
+ if (q >= high || p < mid && c.compare(src[p], src[q]) <= 0)
+ dest[i] = src[p++];
+ else
+ dest[i] = src[q++];
+ }
+ }
+
+ // Parallel prefix
+
+ /**
+ * Cumulates, in parallel, each element of the given array in place,
+ * using the supplied function. For example if the array initially
+ * holds {@code [2, 1, 0, 3]} and the operation performs addition,
+ * then upon return the array holds {@code [2, 3, 3, 6]}.
+ * Parallel prefix computation is usually more efficient than
+ * sequential loops for large arrays.
+ *
+ * @param the class of the objects in the array
+ * @param array the array, which is modified in-place by this method
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(T[] array, BinaryOperator op) {
+ Objects.requireNonNull(op);
+ if (array.length > 0)
+ new ArrayPrefixHelpers.CumulateTask<>
+ (null, op, array, 0, array.length).invoke();
+ }
+
+ /**
+ * Performs {@link #parallelPrefix(Object[], BinaryOperator)}
+ * for the given subrange of the array.
+ *
+ * @param the class of the objects in the array
+ * @param array the array
+ * @param fromIndex the index of the first element, inclusive
+ * @param toIndex the index of the last element, exclusive
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > array.length}
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(T[] array, int fromIndex,
+ int toIndex, BinaryOperator op) {
+ Objects.requireNonNull(op);
+ rangeCheck(array.length, fromIndex, toIndex);
+ if (fromIndex < toIndex)
+ new ArrayPrefixHelpers.CumulateTask<>
+ (null, op, array, fromIndex, toIndex).invoke();
+ }
+
+ /**
+ * Cumulates, in parallel, each element of the given array in place,
+ * using the supplied function. For example if the array initially
+ * holds {@code [2, 1, 0, 3]} and the operation performs addition,
+ * then upon return the array holds {@code [2, 3, 3, 6]}.
+ * Parallel prefix computation is usually more efficient than
+ * sequential loops for large arrays.
+ *
+ * @param array the array, which is modified in-place by this method
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(long[] array, LongBinaryOperator op) {
+ Objects.requireNonNull(op);
+ if (array.length > 0)
+ new ArrayPrefixHelpers.LongCumulateTask
+ (null, op, array, 0, array.length).invoke();
+ }
+
+ /**
+ * Performs {@link #parallelPrefix(long[], LongBinaryOperator)}
+ * for the given subrange of the array.
+ *
+ * @param array the array
+ * @param fromIndex the index of the first element, inclusive
+ * @param toIndex the index of the last element, exclusive
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > array.length}
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(long[] array, int fromIndex,
+ int toIndex, LongBinaryOperator op) {
+ Objects.requireNonNull(op);
+ rangeCheck(array.length, fromIndex, toIndex);
+ if (fromIndex < toIndex)
+ new ArrayPrefixHelpers.LongCumulateTask
+ (null, op, array, fromIndex, toIndex).invoke();
+ }
+
+ /**
+ * Cumulates, in parallel, each element of the given array in place,
+ * using the supplied function. For example if the array initially
+ * holds {@code [2.0, 1.0, 0.0, 3.0]} and the operation performs addition,
+ * then upon return the array holds {@code [2.0, 3.0, 3.0, 6.0]}.
+ * Parallel prefix computation is usually more efficient than
+ * sequential loops for large arrays.
+ *
+ * Because floating-point operations may not be strictly associative,
+ * the returned result may not be identical to the value that would be
+ * obtained if the operation was performed sequentially.
+ *
+ * @param array the array, which is modified in-place by this method
+ * @param op a side-effect-free function to perform the cumulation
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(double[] array, DoubleBinaryOperator op) {
+ Objects.requireNonNull(op);
+ if (array.length > 0)
+ new ArrayPrefixHelpers.DoubleCumulateTask
+ (null, op, array, 0, array.length).invoke();
+ }
+
+ /**
+ * Performs {@link #parallelPrefix(double[], DoubleBinaryOperator)}
+ * for the given subrange of the array.
+ *
+ * @param array the array
+ * @param fromIndex the index of the first element, inclusive
+ * @param toIndex the index of the last element, exclusive
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > array.length}
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(double[] array, int fromIndex,
+ int toIndex, DoubleBinaryOperator op) {
+ Objects.requireNonNull(op);
+ rangeCheck(array.length, fromIndex, toIndex);
+ if (fromIndex < toIndex)
+ new ArrayPrefixHelpers.DoubleCumulateTask
+ (null, op, array, fromIndex, toIndex).invoke();
+ }
+
+ /**
+ * Cumulates, in parallel, each element of the given array in place,
+ * using the supplied function. For example if the array initially
+ * holds {@code [2, 1, 0, 3]} and the operation performs addition,
+ * then upon return the array holds {@code [2, 3, 3, 6]}.
+ * Parallel prefix computation is usually more efficient than
+ * sequential loops for large arrays.
+ *
+ * @param array the array, which is modified in-place by this method
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(int[] array, IntBinaryOperator op) {
+ Objects.requireNonNull(op);
+ if (array.length > 0)
+ new ArrayPrefixHelpers.IntCumulateTask
+ (null, op, array, 0, array.length).invoke();
+ }
+
+ /**
+ * Performs {@link #parallelPrefix(int[], IntBinaryOperator)}
+ * for the given subrange of the array.
+ *
+ * @param array the array
+ * @param fromIndex the index of the first element, inclusive
+ * @param toIndex the index of the last element, exclusive
+ * @param op a side-effect-free, associative function to perform the
+ * cumulation
+ * @throws IllegalArgumentException if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0} or {@code toIndex > array.length}
+ * @throws NullPointerException if the specified array or function is null
+ * @since 1.8
+ */
+ public static void parallelPrefix(int[] array, int fromIndex,
+ int toIndex, IntBinaryOperator op) {
+ Objects.requireNonNull(op);
+ rangeCheck(array.length, fromIndex, toIndex);
+ if (fromIndex < toIndex)
+ new ArrayPrefixHelpers.IntCumulateTask
+ (null, op, array, fromIndex, toIndex).invoke();
+ }
+
+ // Searching
+
+ /**
+ * Searches the specified array of longs for the specified value using the
+ * binary search algorithm. The array must be sorted (as
+ * by the {@link #sort(long[])} method) prior to making this call. If it
+ * is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(long[] a, long key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of longs for the specified value using the
+ * binary search algorithm.
+ * The range must be sorted (as
+ * by the {@link #sort(long[], int, int)} method)
+ * prior to making this call. If it
+ * is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(long[] a, int fromIndex, int toIndex,
+ long key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(long[] a, int fromIndex, int toIndex,
+ long key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ long midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1;
+ else if (midVal > key)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of ints for the specified value using the
+ * binary search algorithm. The array must be sorted (as
+ * by the {@link #sort(int[])} method) prior to making this call. If it
+ * is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(int[] a, int key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of ints for the specified value using the
+ * binary search algorithm.
+ * The range must be sorted (as
+ * by the {@link #sort(int[], int, int)} method)
+ * prior to making this call. If it
+ * is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(int[] a, int fromIndex, int toIndex,
+ int key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(int[] a, int fromIndex, int toIndex,
+ int key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ int midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1;
+ else if (midVal > key)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of shorts for the specified value using
+ * the binary search algorithm. The array must be sorted
+ * (as by the {@link #sort(short[])} method) prior to making this call. If
+ * it is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(short[] a, short key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of shorts for the specified value using
+ * the binary search algorithm.
+ * The range must be sorted
+ * (as by the {@link #sort(short[], int, int)} method)
+ * prior to making this call. If
+ * it is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(short[] a, int fromIndex, int toIndex,
+ short key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(short[] a, int fromIndex, int toIndex,
+ short key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ short midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1;
+ else if (midVal > key)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of chars for the specified value using the
+ * binary search algorithm. The array must be sorted (as
+ * by the {@link #sort(char[])} method) prior to making this call. If it
+ * is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(char[] a, char key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of chars for the specified value using the
+ * binary search algorithm.
+ * The range must be sorted (as
+ * by the {@link #sort(char[], int, int)} method)
+ * prior to making this call. If it
+ * is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(char[] a, int fromIndex, int toIndex,
+ char key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(char[] a, int fromIndex, int toIndex,
+ char key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ char midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1;
+ else if (midVal > key)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of bytes for the specified value using the
+ * binary search algorithm. The array must be sorted (as
+ * by the {@link #sort(byte[])} method) prior to making this call. If it
+ * is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(byte[] a, byte key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of bytes for the specified value using the
+ * binary search algorithm.
+ * The range must be sorted (as
+ * by the {@link #sort(byte[], int, int)} method)
+ * prior to making this call. If it
+ * is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(byte[] a, int fromIndex, int toIndex,
+ byte key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(byte[] a, int fromIndex, int toIndex,
+ byte key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ byte midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1;
+ else if (midVal > key)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of doubles for the specified value using
+ * the binary search algorithm. The array must be sorted
+ * (as by the {@link #sort(double[])} method) prior to making this call.
+ * If it is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found. This method considers all NaN values to be
+ * equivalent and equal.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(double[] a, double key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of doubles for the specified value using
+ * the binary search algorithm.
+ * The range must be sorted
+ * (as by the {@link #sort(double[], int, int)} method)
+ * prior to making this call.
+ * If it is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found. This method considers all NaN values to be
+ * equivalent and equal.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(double[] a, int fromIndex, int toIndex,
+ double key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(double[] a, int fromIndex, int toIndex,
+ double key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ double midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1; // Neither val is NaN, thisVal is smaller
+ else if (midVal > key)
+ high = mid - 1; // Neither val is NaN, thisVal is larger
+ else {
+ long midBits = Double.doubleToLongBits(midVal);
+ long keyBits = Double.doubleToLongBits(key);
+ if (midBits == keyBits) // Values are equal
+ return mid; // Key found
+ else if (midBits < keyBits) // (-0.0, 0.0) or (!NaN, NaN)
+ low = mid + 1;
+ else // (0.0, -0.0) or (NaN, !NaN)
+ high = mid - 1;
+ }
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array of floats for the specified value using
+ * the binary search algorithm. The array must be sorted
+ * (as by the {@link #sort(float[])} method) prior to making this call. If
+ * it is not sorted, the results are undefined. If the array contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found. This method considers all NaN values to be
+ * equivalent and equal.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ */
+ public static int binarySearch(float[] a, float key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array of floats for the specified value using
+ * the binary search algorithm.
+ * The range must be sorted
+ * (as by the {@link #sort(float[], int, int)} method)
+ * prior to making this call. If
+ * it is not sorted, the results are undefined. If the range contains
+ * multiple elements with the specified value, there is no guarantee which
+ * one will be found. This method considers all NaN values to be
+ * equivalent and equal.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(float[] a, int fromIndex, int toIndex,
+ float key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(float[] a, int fromIndex, int toIndex,
+ float key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ float midVal = a[mid];
+
+ if (midVal < key)
+ low = mid + 1; // Neither val is NaN, thisVal is smaller
+ else if (midVal > key)
+ high = mid - 1; // Neither val is NaN, thisVal is larger
+ else {
+ int midBits = Float.floatToIntBits(midVal);
+ int keyBits = Float.floatToIntBits(key);
+ if (midBits == keyBits) // Values are equal
+ return mid; // Key found
+ else if (midBits < keyBits) // (-0.0, 0.0) or (!NaN, NaN)
+ low = mid + 1;
+ else // (0.0, -0.0) or (NaN, !NaN)
+ high = mid - 1;
+ }
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array for the specified object using the binary
+ * search algorithm. The array must be sorted into ascending order
+ * according to the
+ * {@linkplain Comparable natural ordering}
+ * of its elements (as by the
+ * {@link #sort(Object[])} method) prior to making this call.
+ * If it is not sorted, the results are undefined.
+ * (If the array contains elements that are not mutually comparable (for
+ * example, strings and integers), it cannot be sorted according
+ * to the natural ordering of its elements, hence results are undefined.)
+ * If the array contains multiple
+ * elements equal to the specified object, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws ClassCastException if the search key is not comparable to the
+ * elements of the array.
+ */
+ public static int binarySearch(Object[] a, Object key) {
+ return binarySearch0(a, 0, a.length, key);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array for the specified object using the binary
+ * search algorithm.
+ * The range must be sorted into ascending order
+ * according to the
+ * {@linkplain Comparable natural ordering}
+ * of its elements (as by the
+ * {@link #sort(Object[], int, int)} method) prior to making this
+ * call. If it is not sorted, the results are undefined.
+ * (If the range contains elements that are not mutually comparable (for
+ * example, strings and integers), it cannot be sorted according
+ * to the natural ordering of its elements, hence results are undefined.)
+ * If the range contains multiple
+ * elements equal to the specified object, there is no guarantee which
+ * one will be found.
+ *
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws ClassCastException if the search key is not comparable to the
+ * elements of the array within the specified range.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(Object[] a, int fromIndex, int toIndex,
+ Object key) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(Object[] a, int fromIndex, int toIndex,
+ Object key) {
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ @SuppressWarnings("rawtypes")
+ Comparable midVal = (Comparable)a[mid];
+ @SuppressWarnings("unchecked")
+ int cmp = midVal.compareTo(key);
+
+ if (cmp < 0)
+ low = mid + 1;
+ else if (cmp > 0)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ /**
+ * Searches the specified array for the specified object using the binary
+ * search algorithm. The array must be sorted into ascending order
+ * according to the specified comparator (as by the
+ * {@link #sort(Object[], Comparator) sort(T[], Comparator)}
+ * method) prior to making this call. If it is
+ * not sorted, the results are undefined.
+ * If the array contains multiple
+ * elements equal to the specified object, there is no guarantee which one
+ * will be found.
+ *
+ * @param the class of the objects in the array
+ * @param a the array to be searched
+ * @param key the value to be searched for
+ * @param c the comparator by which the array is ordered. A
+ * null value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @return index of the search key, if it is contained in the array;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element greater than the key, or a.length if all
+ * elements in the array are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws ClassCastException if the array contains elements that are not
+ * mutually comparable using the specified comparator,
+ * or the search key is not comparable to the
+ * elements of the array using this comparator.
+ */
+ public static int binarySearch(T[] a, T key, Comparator c) {
+ return binarySearch0(a, 0, a.length, key, c);
+ }
+
+ /**
+ * Searches a range of
+ * the specified array for the specified object using the binary
+ * search algorithm.
+ * The range must be sorted into ascending order
+ * according to the specified comparator (as by the
+ * {@link #sort(Object[], int, int, Comparator)
+ * sort(T[], int, int, Comparator)}
+ * method) prior to making this call.
+ * If it is not sorted, the results are undefined.
+ * If the range contains multiple elements equal to the specified object,
+ * there is no guarantee which one will be found.
+ *
+ * @param the class of the objects in the array
+ * @param a the array to be searched
+ * @param fromIndex the index of the first element (inclusive) to be
+ * searched
+ * @param toIndex the index of the last element (exclusive) to be searched
+ * @param key the value to be searched for
+ * @param c the comparator by which the array is ordered. A
+ * null value indicates that the elements'
+ * {@linkplain Comparable natural ordering} should be used.
+ * @return index of the search key, if it is contained in the array
+ * within the specified range;
+ * otherwise, (-(insertion point ) - 1) . The
+ * insertion point is defined as the point at which the
+ * key would be inserted into the array: the index of the first
+ * element in the range greater than the key,
+ * or toIndex if all
+ * elements in the range are less than the specified key. Note
+ * that this guarantees that the return value will be >= 0 if
+ * and only if the key is found.
+ * @throws ClassCastException if the range contains elements that are not
+ * mutually comparable using the specified comparator,
+ * or the search key is not comparable to the
+ * elements in the range using this comparator.
+ * @throws IllegalArgumentException
+ * if {@code fromIndex > toIndex}
+ * @throws ArrayIndexOutOfBoundsException
+ * if {@code fromIndex < 0 or toIndex > a.length}
+ * @since 1.6
+ */
+ public static int binarySearch(T[] a, int fromIndex, int toIndex,
+ T key, Comparator c) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ return binarySearch0(a, fromIndex, toIndex, key, c);
+ }
+
+ // Like public version, but without range checks.
+ private static int binarySearch0(T[] a, int fromIndex, int toIndex,
+ T key, Comparator c) {
+ if (c == null) {
+ return binarySearch0(a, fromIndex, toIndex, key);
+ }
+ int low = fromIndex;
+ int high = toIndex - 1;
+
+ while (low <= high) {
+ int mid = (low + high) >>> 1;
+ T midVal = a[mid];
+ int cmp = c.compare(midVal, key);
+ if (cmp < 0)
+ low = mid + 1;
+ else if (cmp > 0)
+ high = mid - 1;
+ else
+ return mid; // key found
+ }
+ return -(low + 1); // key not found.
+ }
+
+ // Equality Testing
+
+ /**
+ * Returns true if the two specified arrays of longs are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(long[] a, long[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of ints are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(int[] a, int[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of shorts are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(short[] a, short a2[]) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of chars are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(char[] a, char[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of bytes are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(byte[] a, byte[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of booleans are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(boolean[] a, boolean[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of doubles are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * Two doubles d1 and d2 are considered equal if:
+ * new Double(d1).equals(new Double(d2))
+ * (Unlike the == operator, this method considers
+ * NaN equals to itself, and 0.0d unequal to -0.0d.)
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ * @see Double#equals(Object)
+ */
+ public static boolean equals(double[] a, double[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of floats are
+ * equal to one another. Two arrays are considered equal if both
+ * arrays contain the same number of elements, and all corresponding pairs
+ * of elements in the two arrays are equal. In other words, two arrays
+ * are equal if they contain the same elements in the same order. Also,
+ * two array references are considered equal if both are null .
+ *
+ * Two floats f1 and f2 are considered equal if:
+ * new Float(f1).equals(new Float(f2))
+ * (Unlike the == operator, this method considers
+ * NaN equals to itself, and 0.0f unequal to -0.0f.)
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ * @see Float#equals(Object)
+ */
+ public static boolean equals(float[] a, float[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; itrue if the two specified arrays of Objects are
+ * equal to one another. The two arrays are considered equal if
+ * both arrays contain the same number of elements, and all corresponding
+ * pairs of elements in the two arrays are equal. Two objects e1
+ * and e2 are considered equal if (e1==null ? e2==null
+ * : e1.equals(e2)) . In other words, the two arrays are equal if
+ * they contain the same elements in the same order. Also, two array
+ * references are considered equal if both are null .
+ *
+ * @param a one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ */
+ public static boolean equals(Object[] a, Object[] a2) {
+ if (a==a2)
+ return true;
+ if (a==null || a2==null)
+ return false;
+
+ int length = a.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i=0; ifromIndex, inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(long[] a, int fromIndex, int toIndex, long val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified int value to each element of the specified array
+ * of ints.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(int[] a, int val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified int value to each element of the specified
+ * range of the specified array of ints. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(int[] a, int fromIndex, int toIndex, int val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified short value to each element of the specified array
+ * of shorts.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(short[] a, short val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified short value to each element of the specified
+ * range of the specified array of shorts. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(short[] a, int fromIndex, int toIndex, short val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified char value to each element of the specified array
+ * of chars.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(char[] a, char val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified char value to each element of the specified
+ * range of the specified array of chars. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(char[] a, int fromIndex, int toIndex, char val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified byte value to each element of the specified array
+ * of bytes.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(byte[] a, byte val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified byte value to each element of the specified
+ * range of the specified array of bytes. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(byte[] a, int fromIndex, int toIndex, byte val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified boolean value to each element of the specified
+ * array of booleans.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(boolean[] a, boolean val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified boolean value to each element of the specified
+ * range of the specified array of booleans. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(boolean[] a, int fromIndex, int toIndex,
+ boolean val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified double value to each element of the specified
+ * array of doubles.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(double[] a, double val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified double value to each element of the specified
+ * range of the specified array of doubles. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(double[] a, int fromIndex, int toIndex,double val){
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified float value to each element of the specified array
+ * of floats.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ */
+ public static void fill(float[] a, float val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified float value to each element of the specified
+ * range of the specified array of floats. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ */
+ public static void fill(float[] a, int fromIndex, int toIndex, float val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified Object reference to each element of the specified
+ * array of Objects.
+ *
+ * @param a the array to be filled
+ * @param val the value to be stored in all elements of the array
+ * @throws ArrayStoreException if the specified value is not of a
+ * runtime type that can be stored in the specified array
+ */
+ public static void fill(Object[] a, Object val) {
+ for (int i = 0, len = a.length; i < len; i++)
+ a[i] = val;
+ }
+
+ /**
+ * Assigns the specified Object reference to each element of the specified
+ * range of the specified array of Objects. The range to be filled
+ * extends from index fromIndex , inclusive, to index
+ * toIndex , exclusive. (If fromIndex==toIndex , the
+ * range to be filled is empty.)
+ *
+ * @param a the array to be filled
+ * @param fromIndex the index of the first element (inclusive) to be
+ * filled with the specified value
+ * @param toIndex the index of the last element (exclusive) to be
+ * filled with the specified value
+ * @param val the value to be stored in all elements of the array
+ * @throws IllegalArgumentException if fromIndex > toIndex
+ * @throws ArrayIndexOutOfBoundsException if fromIndex < 0 or
+ * toIndex > a.length
+ * @throws ArrayStoreException if the specified value is not of a
+ * runtime type that can be stored in the specified array
+ */
+ public static void fill(Object[] a, int fromIndex, int toIndex, Object val) {
+ rangeCheck(a.length, fromIndex, toIndex);
+ for (int i = fromIndex; i < toIndex; i++)
+ a[i] = val;
+ }
+
+ // Cloning
+
+ /**
+ * Copies the specified array, truncating or padding with nulls (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain null .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ * The resulting array is of exactly the same class as the original array.
+ *
+ * @param the class of the objects in the array
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with nulls
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ @SuppressWarnings("unchecked")
+ public static T[] copyOf(T[] original, int newLength) {
+ return (T[]) copyOf(original, newLength, original.getClass());
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with nulls (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain null .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ * The resulting array is of the class newType .
+ *
+ * @param the class of the objects in the original array
+ * @param the class of the objects in the returned array
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @param newType the class of the copy to be returned
+ * @return a copy of the original array, truncated or padded with nulls
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @throws ArrayStoreException if an element copied from
+ * original is not of a runtime type that can be stored in
+ * an array of class newType
+ * @since 1.6
+ */
+ public static T[] copyOf(U[] original, int newLength, Class newType) {
+ @SuppressWarnings("unchecked")
+ T[] copy = ((Object)newType == (Object)Object[].class)
+ ? (T[]) new Object[newLength]
+ : (T[]) Array.newInstance(newType.getComponentType(), newLength);
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain (byte)0 .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static byte[] copyOf(byte[] original, int newLength) {
+ byte[] copy = new byte[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain (short)0 .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static short[] copyOf(short[] original, int newLength) {
+ short[] copy = new short[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain 0 .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static int[] copyOf(int[] original, int newLength) {
+ int[] copy = new int[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain 0L .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static long[] copyOf(long[] original, int newLength) {
+ long[] copy = new long[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with null characters (if necessary)
+ * so the copy has the specified length. For all indices that are valid
+ * in both the original array and the copy, the two arrays will contain
+ * identical values. For any indices that are valid in the copy but not
+ * the original, the copy will contain '\\u000' . Such indices
+ * will exist if and only if the specified length is greater than that of
+ * the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with null characters
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static char[] copyOf(char[] original, int newLength) {
+ char[] copy = new char[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain 0f .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static float[] copyOf(float[] original, int newLength) {
+ float[] copy = new float[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with zeros (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain 0d .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with zeros
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static double[] copyOf(double[] original, int newLength) {
+ double[] copy = new double[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified array, truncating or padding with false (if necessary)
+ * so the copy has the specified length. For all indices that are
+ * valid in both the original array and the copy, the two arrays will
+ * contain identical values. For any indices that are valid in the
+ * copy but not the original, the copy will contain false .
+ * Such indices will exist if and only if the specified length
+ * is greater than that of the original array.
+ *
+ * @param original the array to be copied
+ * @param newLength the length of the copy to be returned
+ * @return a copy of the original array, truncated or padded with false elements
+ * to obtain the specified length
+ * @throws NegativeArraySizeException if newLength is negative
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static boolean[] copyOf(boolean[] original, int newLength) {
+ boolean[] copy = new boolean[newLength];
+ System.arraycopy(original, 0, copy, 0,
+ Math.min(original.length, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * null is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * The resulting array is of exactly the same class as the original array.
+ *
+ * @param the class of the objects in the array
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with nulls to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ @SuppressWarnings("unchecked")
+ public static T[] copyOfRange(T[] original, int from, int to) {
+ return copyOfRange(original, from, to, (Class) original.getClass());
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * null is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ * The resulting array is of the class newType .
+ *
+ * @param the class of the objects in the original array
+ * @param the class of the objects in the returned array
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @param newType the class of the copy to be returned
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with nulls to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @throws ArrayStoreException if an element copied from
+ * original is not of a runtime type that can be stored in
+ * an array of class newType .
+ * @since 1.6
+ */
+ public static T[] copyOfRange(U[] original, int from, int to, Class newType) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ @SuppressWarnings("unchecked")
+ T[] copy = ((Object)newType == (Object)Object[].class)
+ ? (T[]) new Object[newLength]
+ : (T[]) Array.newInstance(newType.getComponentType(), newLength);
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * (byte)0 is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static byte[] copyOfRange(byte[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ byte[] copy = new byte[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * (short)0 is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static short[] copyOfRange(short[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ short[] copy = new short[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * 0 is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static int[] copyOfRange(int[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ int[] copy = new int[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * 0L is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static long[] copyOfRange(long[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ long[] copy = new long[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * '\\u000' is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with null characters to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static char[] copyOfRange(char[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ char[] copy = new char[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * 0f is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static float[] copyOfRange(float[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ float[] copy = new float[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * 0d is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with zeros to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static double[] copyOfRange(double[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ double[] copy = new double[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ /**
+ * Copies the specified range of the specified array into a new array.
+ * The initial index of the range (from ) must lie between zero
+ * and original.length , inclusive. The value at
+ * original[from] is placed into the initial element of the copy
+ * (unless from == original.length or from == to ).
+ * Values from subsequent elements in the original array are placed into
+ * subsequent elements in the copy. The final index of the range
+ * (to ), which must be greater than or equal to from ,
+ * may be greater than original.length , in which case
+ * false is placed in all elements of the copy whose index is
+ * greater than or equal to original.length - from . The length
+ * of the returned array will be to - from .
+ *
+ * @param original the array from which a range is to be copied
+ * @param from the initial index of the range to be copied, inclusive
+ * @param to the final index of the range to be copied, exclusive.
+ * (This index may lie outside the array.)
+ * @return a new array containing the specified range from the original array,
+ * truncated or padded with false elements to obtain the required length
+ * @throws ArrayIndexOutOfBoundsException if {@code from < 0}
+ * or {@code from > original.length}
+ * @throws IllegalArgumentException if from > to
+ * @throws NullPointerException if original is null
+ * @since 1.6
+ */
+ public static boolean[] copyOfRange(boolean[] original, int from, int to) {
+ int newLength = to - from;
+ if (newLength < 0)
+ throw new IllegalArgumentException(from + " > " + to);
+ boolean[] copy = new boolean[newLength];
+ System.arraycopy(original, from, copy, 0,
+ Math.min(original.length - from, newLength));
+ return copy;
+ }
+
+ // Misc
+
+ /**
+ * Returns a fixed-size list backed by the specified array. (Changes to
+ * the returned list "write through" to the array.) This method acts
+ * as bridge between array-based and collection-based APIs, in
+ * combination with {@link Collection#toArray}. The returned list is
+ * serializable and implements {@link RandomAccess}.
+ *
+ * This method also provides a convenient way to create a fixed-size
+ * list initialized to contain several elements:
+ *
+ * List<String> stooges = Arrays.asList("Larry", "Moe", "Curly");
+ *
+ *
+ * @param the class of the objects in the array
+ * @param a the array by which the list will be backed
+ * @return a list view of the specified array
+ */
+ @SafeVarargs
+ @SuppressWarnings("varargs")
+ public static List asList(T... a) {
+ return new ArrayList<>(a);
+ }
+
+ /**
+ * @serial include
+ */
+ private static class ArrayList extends AbstractList
+ implements RandomAccess, java.io.Serializable
+ {
+ private static final long serialVersionUID = -2764017481108945198L;
+ private final E[] a;
+
+ ArrayList(E[] array) {
+ a = Objects.requireNonNull(array);
+ }
+
+ @Override
+ public int size() {
+ return a.length;
+ }
+
+ @Override
+ public Object[] toArray() {
+ return a.clone();
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public T[] toArray(T[] a) {
+ int size = size();
+ if (a.length < size)
+ return Arrays.copyOf(this.a, size,
+ (Class) a.getClass());
+ System.arraycopy(this.a, 0, a, 0, size);
+ if (a.length > size)
+ a[size] = null;
+ return a;
+ }
+
+ @Override
+ public E get(int index) {
+ return a[index];
+ }
+
+ @Override
+ public E set(int index, E element) {
+ E oldValue = a[index];
+ a[index] = element;
+ return oldValue;
+ }
+
+ @Override
+ public int indexOf(Object o) {
+ E[] a = this.a;
+ if (o == null) {
+ for (int i = 0; i < a.length; i++)
+ if (a[i] == null)
+ return i;
+ } else {
+ for (int i = 0; i < a.length; i++)
+ if (o.equals(a[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ @Override
+ public boolean contains(Object o) {
+ return indexOf(o) != -1;
+ }
+
+ @Override
+ public Spliterator spliterator() {
+ return Spliterators.spliterator(a, Spliterator.ORDERED);
+ }
+
+ @Override
+ public void forEach(Consumer action) {
+ Objects.requireNonNull(action);
+ for (E e : a) {
+ action.accept(e);
+ }
+ }
+
+ @Override
+ public void replaceAll(UnaryOperator operator) {
+ Objects.requireNonNull(operator);
+ E[] a = this.a;
+ for (int i = 0; i < a.length; i++) {
+ a[i] = operator.apply(a[i]);
+ }
+ }
+
+ @Override
+ public void sort(Comparator c) {
+ Arrays.sort(a, c);
+ }
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two long arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ * The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Long}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(long a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (long element : a) {
+ int elementHash = (int)(element ^ (element >>> 32));
+ result = 31 * result + elementHash;
+ }
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two non-null int arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Integer}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(int a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (int element : a)
+ result = 31 * result + element;
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two short arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Short}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(short a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (short element : a)
+ result = 31 * result + element;
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two char arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Character}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(char a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (char element : a)
+ result = 31 * result + element;
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two byte arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Byte}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(byte a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (byte element : a)
+ result = 31 * result + element;
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two boolean arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Boolean}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(boolean a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (boolean element : a)
+ result = 31 * result + (element ? 1231 : 1237);
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two float arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Float}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(float a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (float element : a)
+ result = 31 * result + Float.floatToIntBits(element);
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array.
+ * For any two double arrays a and b
+ * such that Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is the same value that would be
+ * obtained by invoking the {@link List#hashCode() hashCode }
+ * method on a {@link List} containing a sequence of {@link Double}
+ * instances representing the elements of a in the same order.
+ * If a is null , this method returns 0.
+ *
+ * @param a the array whose hash value to compute
+ * @return a content-based hash code for a
+ * @since 1.5
+ */
+ public static int hashCode(double a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+ for (double element : a) {
+ long bits = Double.doubleToLongBits(element);
+ result = 31 * result + (int)(bits ^ (bits >>> 32));
+ }
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the contents of the specified array. If
+ * the array contains other arrays as elements, the hash code is based on
+ * their identities rather than their contents. It is therefore
+ * acceptable to invoke this method on an array that contains itself as an
+ * element, either directly or indirectly through one or more levels of
+ * arrays.
+ *
+ *
For any two arrays a and b such that
+ * Arrays.equals(a, b) , it is also the case that
+ * Arrays.hashCode(a) == Arrays.hashCode(b) .
+ *
+ *
The value returned by this method is equal to the value that would
+ * be returned by Arrays.asList(a).hashCode() , unless a
+ * is null , in which case 0 is returned.
+ *
+ * @param a the array whose content-based hash code to compute
+ * @return a content-based hash code for a
+ * @see #deepHashCode(Object[])
+ * @since 1.5
+ */
+ public static int hashCode(Object a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+
+ for (Object element : a)
+ result = 31 * result + (element == null ? 0 : element.hashCode());
+
+ return result;
+ }
+
+ /**
+ * Returns a hash code based on the "deep contents" of the specified
+ * array. If the array contains other arrays as elements, the
+ * hash code is based on their contents and so on, ad infinitum.
+ * It is therefore unacceptable to invoke this method on an array that
+ * contains itself as an element, either directly or indirectly through
+ * one or more levels of arrays. The behavior of such an invocation is
+ * undefined.
+ *
+ *
For any two arrays a and b such that
+ * Arrays.deepEquals(a, b) , it is also the case that
+ * Arrays.deepHashCode(a) == Arrays.deepHashCode(b) .
+ *
+ *
The computation of the value returned by this method is similar to
+ * that of the value returned by {@link List#hashCode()} on a list
+ * containing the same elements as a in the same order, with one
+ * difference: If an element e of a is itself an array,
+ * its hash code is computed not by calling e.hashCode() , but as
+ * by calling the appropriate overloading of Arrays.hashCode(e)
+ * if e is an array of a primitive type, or as by calling
+ * Arrays.deepHashCode(e) recursively if e is an array
+ * of a reference type. If a is null , this method
+ * returns 0.
+ *
+ * @param a the array whose deep-content-based hash code to compute
+ * @return a deep-content-based hash code for a
+ * @see #hashCode(Object[])
+ * @since 1.5
+ */
+ public static int deepHashCode(Object a[]) {
+ if (a == null)
+ return 0;
+
+ int result = 1;
+
+ for (Object element : a) {
+ int elementHash = 0;
+ if (element instanceof Object[])
+ elementHash = deepHashCode((Object[]) element);
+ else if (element instanceof byte[])
+ elementHash = hashCode((byte[]) element);
+ else if (element instanceof short[])
+ elementHash = hashCode((short[]) element);
+ else if (element instanceof int[])
+ elementHash = hashCode((int[]) element);
+ else if (element instanceof long[])
+ elementHash = hashCode((long[]) element);
+ else if (element instanceof char[])
+ elementHash = hashCode((char[]) element);
+ else if (element instanceof float[])
+ elementHash = hashCode((float[]) element);
+ else if (element instanceof double[])
+ elementHash = hashCode((double[]) element);
+ else if (element instanceof boolean[])
+ elementHash = hashCode((boolean[]) element);
+ else if (element != null)
+ elementHash = element.hashCode();
+
+ result = 31 * result + elementHash;
+ }
+
+ return result;
+ }
+
+ /**
+ * Returns true if the two specified arrays are deeply
+ * equal to one another. Unlike the {@link #equals(Object[],Object[])}
+ * method, this method is appropriate for use with nested arrays of
+ * arbitrary depth.
+ *
+ *
Two array references are considered deeply equal if both
+ * are null , or if they refer to arrays that contain the same
+ * number of elements and all corresponding pairs of elements in the two
+ * arrays are deeply equal.
+ *
+ *
Two possibly null elements e1 and e2 are
+ * deeply equal if any of the following conditions hold:
+ *
+ * e1 and e2 are both arrays of object reference
+ * types, and Arrays.deepEquals(e1, e2) would return true
+ * e1 and e2 are arrays of the same primitive
+ * type, and the appropriate overloading of
+ * Arrays.equals(e1, e2) would return true.
+ * e1 == e2
+ * e1.equals(e2) would return true.
+ *
+ * Note that this definition permits null elements at any depth.
+ *
+ * If either of the specified arrays contain themselves as elements
+ * either directly or indirectly through one or more levels of arrays,
+ * the behavior of this method is undefined.
+ *
+ * @param a1 one array to be tested for equality
+ * @param a2 the other array to be tested for equality
+ * @return true if the two arrays are equal
+ * @see #equals(Object[],Object[])
+ * @see Objects#deepEquals(Object, Object)
+ * @since 1.5
+ */
+ public static boolean deepEquals(Object[] a1, Object[] a2) {
+ if (a1 == a2)
+ return true;
+ if (a1 == null || a2==null)
+ return false;
+ int length = a1.length;
+ if (a2.length != length)
+ return false;
+
+ for (int i = 0; i < length; i++) {
+ Object e1 = a1[i];
+ Object e2 = a2[i];
+
+ if (e1 == e2)
+ continue;
+ if (e1 == null)
+ return false;
+
+ // Figure out whether the two elements are equal
+ boolean eq = deepEquals0(e1, e2);
+
+ if (!eq)
+ return false;
+ }
+ return true;
+ }
+
+ static boolean deepEquals0(Object e1, Object e2) {
+ assert e1 != null;
+ boolean eq;
+ if (e1 instanceof Object[] && e2 instanceof Object[])
+ eq = deepEquals ((Object[]) e1, (Object[]) e2);
+ else if (e1 instanceof byte[] && e2 instanceof byte[])
+ eq = equals((byte[]) e1, (byte[]) e2);
+ else if (e1 instanceof short[] && e2 instanceof short[])
+ eq = equals((short[]) e1, (short[]) e2);
+ else if (e1 instanceof int[] && e2 instanceof int[])
+ eq = equals((int[]) e1, (int[]) e2);
+ else if (e1 instanceof long[] && e2 instanceof long[])
+ eq = equals((long[]) e1, (long[]) e2);
+ else if (e1 instanceof char[] && e2 instanceof char[])
+ eq = equals((char[]) e1, (char[]) e2);
+ else if (e1 instanceof float[] && e2 instanceof float[])
+ eq = equals((float[]) e1, (float[]) e2);
+ else if (e1 instanceof double[] && e2 instanceof double[])
+ eq = equals((double[]) e1, (double[]) e2);
+ else if (e1 instanceof boolean[] && e2 instanceof boolean[])
+ eq = equals((boolean[]) e1, (boolean[]) e2);
+ else
+ eq = e1.equals(e2);
+ return eq;
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(long) . Returns "null" if a
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(long[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(int) . Returns "null" if a is
+ * null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(int[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(short) . Returns "null" if a
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(short[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(char) . Returns "null" if a
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(char[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements
+ * are separated by the characters ", " (a comma followed
+ * by a space). Elements are converted to strings as by
+ * String.valueOf(byte) . Returns "null" if
+ * a is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(byte[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(boolean) . Returns "null" if
+ * a is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(boolean[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(float) . Returns "null" if a
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(float[] a) {
+ if (a == null)
+ return "null";
+
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * The string representation consists of a list of the array's elements,
+ * enclosed in square brackets ("[]" ). Adjacent elements are
+ * separated by the characters ", " (a comma followed by a
+ * space). Elements are converted to strings as by
+ * String.valueOf(double) . Returns "null" if a
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @since 1.5
+ */
+ public static String toString(double[] a) {
+ if (a == null)
+ return "null";
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(a[i]);
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the contents of the specified array.
+ * If the array contains other arrays as elements, they are converted to
+ * strings by the {@link Object#toString} method inherited from
+ * Object , which describes their identities rather than
+ * their contents.
+ *
+ *
The value returned by this method is equal to the value that would
+ * be returned by Arrays.asList(a).toString() , unless a
+ * is null , in which case "null" is returned.
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @see #deepToString(Object[])
+ * @since 1.5
+ */
+ public static String toString(Object[] a) {
+ if (a == null)
+ return "null";
+
+ int iMax = a.length - 1;
+ if (iMax == -1)
+ return "[]";
+
+ StringBuilder b = new StringBuilder();
+ b.append('[');
+ for (int i = 0; ; i++) {
+ b.append(String.valueOf(a[i]));
+ if (i == iMax)
+ return b.append(']').toString();
+ b.append(", ");
+ }
+ }
+
+ /**
+ * Returns a string representation of the "deep contents" of the specified
+ * array. If the array contains other arrays as elements, the string
+ * representation contains their contents and so on. This method is
+ * designed for converting multidimensional arrays to strings.
+ *
+ *
The string representation consists of a list of the array's
+ * elements, enclosed in square brackets ("[]" ). Adjacent
+ * elements are separated by the characters ", " (a comma
+ * followed by a space). Elements are converted to strings as by
+ * String.valueOf(Object) , unless they are themselves
+ * arrays.
+ *
+ *
If an element e is an array of a primitive type, it is
+ * converted to a string as by invoking the appropriate overloading of
+ * Arrays.toString(e) . If an element e is an array of a
+ * reference type, it is converted to a string as by invoking
+ * this method recursively.
+ *
+ *
To avoid infinite recursion, if the specified array contains itself
+ * as an element, or contains an indirect reference to itself through one
+ * or more levels of arrays, the self-reference is converted to the string
+ * "[...]" . For example, an array containing only a reference
+ * to itself would be rendered as "[[...]]" .
+ *
+ *
This method returns "null" if the specified array
+ * is null .
+ *
+ * @param a the array whose string representation to return
+ * @return a string representation of a
+ * @see #toString(Object[])
+ * @since 1.5
+ */
+ public static String deepToString(Object[] a) {
+ if (a == null)
+ return "null";
+
+ int bufLen = 20 * a.length;
+ if (a.length != 0 && bufLen <= 0)
+ bufLen = Integer.MAX_VALUE;
+ StringBuilder buf = new StringBuilder(bufLen);
+ deepToString(a, buf, new HashSet<>());
+ return buf.toString();
+ }
+
+ private static void deepToString(Object[] a, StringBuilder buf,
+ Set dejaVu) {
+ if (a == null) {
+ buf.append("null");
+ return;
+ }
+ int iMax = a.length - 1;
+ if (iMax == -1) {
+ buf.append("[]");
+ return;
+ }
+
+ dejaVu.add(a);
+ buf.append('[');
+ for (int i = 0; ; i++) {
+
+ Object element = a[i];
+ if (element == null) {
+ buf.append("null");
+ } else {
+ Class eClass = element.getClass();
+
+ if (eClass.isArray()) {
+ if (eClass == byte[].class)
+ buf.append(toString((byte[]) element));
+ else if (eClass == short[].class)
+ buf.append(toString((short[]) element));
+ else if (eClass == int[].class)
+ buf.append(toString((int[]) element));
+ else if (eClass == long[].class)
+ buf.append(toString((long[]) element));
+ else if (eClass == char[].class)
+ buf.append(toString((char[]) element));
+ else if (eClass == float[].class)
+ buf.append(toString((float[]) element));
+ else if (eClass == double[].class)
+ buf.append(toString((double[]) element));
+ else if (eClass == boolean[].class)
+ buf.append(toString((boolean[]) element));
+ else { // element is an array of object references
+ if (dejaVu.contains(element))
+ buf.append("[...]");
+ else
+ deepToString((Object[])element, buf, dejaVu);
+ }
+ } else { // element is non-null and not an array
+ buf.append(element.toString());
+ }
+ }
+ if (i == iMax)
+ break;
+ buf.append(", ");
+ }
+ buf.append(']');
+ dejaVu.remove(a);
+ }
+
+
+ /**
+ * Set all elements of the specified array, using the provided
+ * generator function to compute each element.
+ *
+ * If the generator function throws an exception, it is relayed to
+ * the caller and the array is left in an indeterminate state.
+ *
+ * @param type of elements of the array
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void setAll(T[] array, IntFunction generator) {
+ Objects.requireNonNull(generator);
+ for (int i = 0; i < array.length; i++)
+ array[i] = generator.apply(i);
+ }
+
+ /**
+ * Set all elements of the specified array, in parallel, using the
+ * provided generator function to compute each element.
+ *
+ * If the generator function throws an exception, an unchecked exception
+ * is thrown from {@code parallelSetAll} and the array is left in an
+ * indeterminate state.
+ *
+ * @param type of elements of the array
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void parallelSetAll(T[] array, IntFunction generator) {
+ Objects.requireNonNull(generator);
+ IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.apply(i); });
+ }
+
+ /**
+ * Set all elements of the specified array, using the provided
+ * generator function to compute each element.
+ *
+ * If the generator function throws an exception, it is relayed to
+ * the caller and the array is left in an indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void setAll(int[] array, IntUnaryOperator generator) {
+ Objects.requireNonNull(generator);
+ for (int i = 0; i < array.length; i++)
+ array[i] = generator.applyAsInt(i);
+ }
+
+ /**
+ * Set all elements of the specified array, in parallel, using the
+ * provided generator function to compute each element.
+ *
+ *
If the generator function throws an exception, an unchecked exception
+ * is thrown from {@code parallelSetAll} and the array is left in an
+ * indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void parallelSetAll(int[] array, IntUnaryOperator generator) {
+ Objects.requireNonNull(generator);
+ IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsInt(i); });
+ }
+
+ /**
+ * Set all elements of the specified array, using the provided
+ * generator function to compute each element.
+ *
+ *
If the generator function throws an exception, it is relayed to
+ * the caller and the array is left in an indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void setAll(long[] array, IntToLongFunction generator) {
+ Objects.requireNonNull(generator);
+ for (int i = 0; i < array.length; i++)
+ array[i] = generator.applyAsLong(i);
+ }
+
+ /**
+ * Set all elements of the specified array, in parallel, using the
+ * provided generator function to compute each element.
+ *
+ *
If the generator function throws an exception, an unchecked exception
+ * is thrown from {@code parallelSetAll} and the array is left in an
+ * indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void parallelSetAll(long[] array, IntToLongFunction generator) {
+ Objects.requireNonNull(generator);
+ IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsLong(i); });
+ }
+
+ /**
+ * Set all elements of the specified array, using the provided
+ * generator function to compute each element.
+ *
+ *
If the generator function throws an exception, it is relayed to
+ * the caller and the array is left in an indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void setAll(double[] array, IntToDoubleFunction generator) {
+ Objects.requireNonNull(generator);
+ for (int i = 0; i < array.length; i++)
+ array[i] = generator.applyAsDouble(i);
+ }
+
+ /**
+ * Set all elements of the specified array, in parallel, using the
+ * provided generator function to compute each element.
+ *
+ *
If the generator function throws an exception, an unchecked exception
+ * is thrown from {@code parallelSetAll} and the array is left in an
+ * indeterminate state.
+ *
+ * @param array array to be initialized
+ * @param generator a function accepting an index and producing the desired
+ * value for that position
+ * @throws NullPointerException if the generator is null
+ * @since 1.8
+ */
+ public static void parallelSetAll(double[] array, IntToDoubleFunction generator) {
+ Objects.requireNonNull(generator);
+ IntStream.range(0, array.length).parallel().forEach(i -> { array[i] = generator.applyAsDouble(i); });
+ }
+
+ /**
+ * Returns a {@link Spliterator} covering all of the specified array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param type of elements
+ * @param array the array, assumed to be unmodified during use
+ * @return a spliterator for the array elements
+ * @since 1.8
+ */
+ public static Spliterator spliterator(T[] array) {
+ return Spliterators.spliterator(array,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator} covering the specified range of the
+ * specified array.
+ *
+ * The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param type of elements
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a spliterator for the array elements
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static Spliterator spliterator(T[] array, int startInclusive, int endExclusive) {
+ return Spliterators.spliterator(array, startInclusive, endExclusive,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfInt} covering all of the specified array.
+ *
+ * The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return a spliterator for the array elements
+ * @since 1.8
+ */
+ public static Spliterator.OfInt spliterator(int[] array) {
+ return Spliterators.spliterator(array,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfInt} covering the specified range of the
+ * specified array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a spliterator for the array elements
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static Spliterator.OfInt spliterator(int[] array, int startInclusive, int endExclusive) {
+ return Spliterators.spliterator(array, startInclusive, endExclusive,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfLong} covering all of the specified array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return the spliterator for the array elements
+ * @since 1.8
+ */
+ public static Spliterator.OfLong spliterator(long[] array) {
+ return Spliterators.spliterator(array,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfLong} covering the specified range of the
+ * specified array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a spliterator for the array elements
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static Spliterator.OfLong spliterator(long[] array, int startInclusive, int endExclusive) {
+ return Spliterators.spliterator(array, startInclusive, endExclusive,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfDouble} covering all of the specified
+ * array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return a spliterator for the array elements
+ * @since 1.8
+ */
+ public static Spliterator.OfDouble spliterator(double[] array) {
+ return Spliterators.spliterator(array,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a {@link Spliterator.OfDouble} covering the specified range of
+ * the specified array.
+ *
+ *
The spliterator reports {@link Spliterator#SIZED},
+ * {@link Spliterator#SUBSIZED}, {@link Spliterator#ORDERED}, and
+ * {@link Spliterator#IMMUTABLE}.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a spliterator for the array elements
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static Spliterator.OfDouble spliterator(double[] array, int startInclusive, int endExclusive) {
+ return Spliterators.spliterator(array, startInclusive, endExclusive,
+ Spliterator.ORDERED | Spliterator.IMMUTABLE);
+ }
+
+ /**
+ * Returns a sequential {@link Stream} with the specified array as its
+ * source.
+ *
+ * @param The type of the array elements
+ * @param array The array, assumed to be unmodified during use
+ * @return a {@code Stream} for the array
+ * @since 1.8
+ */
+ public static Stream stream(T[] array) {
+ return stream(array, 0, array.length);
+ }
+
+ /**
+ * Returns a sequential {@link Stream} with the specified range of the
+ * specified array as its source.
+ *
+ * @param the type of the array elements
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a {@code Stream} for the array range
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static Stream stream(T[] array, int startInclusive, int endExclusive) {
+ return StreamSupport.stream(spliterator(array, startInclusive, endExclusive), false);
+ }
+
+ /**
+ * Returns a sequential {@link IntStream} with the specified array as its
+ * source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return an {@code IntStream} for the array
+ * @since 1.8
+ */
+ public static IntStream stream(int[] array) {
+ return stream(array, 0, array.length);
+ }
+
+ /**
+ * Returns a sequential {@link IntStream} with the specified range of the
+ * specified array as its source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return an {@code IntStream} for the array range
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static IntStream stream(int[] array, int startInclusive, int endExclusive) {
+ return StreamSupport.intStream(spliterator(array, startInclusive, endExclusive), false);
+ }
+
+ /**
+ * Returns a sequential {@link LongStream} with the specified array as its
+ * source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return a {@code LongStream} for the array
+ * @since 1.8
+ */
+ public static LongStream stream(long[] array) {
+ return stream(array, 0, array.length);
+ }
+
+ /**
+ * Returns a sequential {@link LongStream} with the specified range of the
+ * specified array as its source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a {@code LongStream} for the array range
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static LongStream stream(long[] array, int startInclusive, int endExclusive) {
+ return StreamSupport.longStream(spliterator(array, startInclusive, endExclusive), false);
+ }
+
+ /**
+ * Returns a sequential {@link DoubleStream} with the specified array as its
+ * source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @return a {@code DoubleStream} for the array
+ * @since 1.8
+ */
+ public static DoubleStream stream(double[] array) {
+ return stream(array, 0, array.length);
+ }
+
+ /**
+ * Returns a sequential {@link DoubleStream} with the specified range of the
+ * specified array as its source.
+ *
+ * @param array the array, assumed to be unmodified during use
+ * @param startInclusive the first index to cover, inclusive
+ * @param endExclusive index immediately past the last index to cover
+ * @return a {@code DoubleStream} for the array range
+ * @throws ArrayIndexOutOfBoundsException if {@code startInclusive} is
+ * negative, {@code endExclusive} is less than
+ * {@code startInclusive}, or {@code endExclusive} is greater than
+ * the array size
+ * @since 1.8
+ */
+ public static DoubleStream stream(double[] array, int startInclusive, int endExclusive) {
+ return StreamSupport.doubleStream(spliterator(array, startInclusive, endExclusive), false);
+ }
+}