--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/ArrayList.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1094 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.util;
+
+/**
+ * Resizable-array implementation of the <tt>List</tt> interface. Implements
+ * all optional list operations, and permits all elements, including
+ * <tt>null</tt>. In addition to implementing the <tt>List</tt> interface,
+ * this class provides methods to manipulate the size of the array that is
+ * used internally to store the list. (This class is roughly equivalent to
+ * <tt>Vector</tt>, except that it is unsynchronized.)
+ *
+ * <p>The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
+ * <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
+ * time. The <tt>add</tt> operation runs in <i>amortized constant time</i>,
+ * that is, adding n elements requires O(n) time. All of the other operations
+ * run in linear time (roughly speaking). The constant factor is low compared
+ * to that for the <tt>LinkedList</tt> implementation.
+ *
+ * <p>Each <tt>ArrayList</tt> instance has a <i>capacity</i>. The capacity is
+ * the size of the array used to store the elements in the list. It is always
+ * at least as large as the list size. As elements are added to an ArrayList,
+ * its capacity grows automatically. The details of the growth policy are not
+ * specified beyond the fact that adding an element has constant amortized
+ * time cost.
+ *
+ * <p>An application can increase the capacity of an <tt>ArrayList</tt> instance
+ * before adding a large number of elements using the <tt>ensureCapacity</tt>
+ * operation. This may reduce the amount of incremental reallocation.
+ *
+ * <p><strong>Note that this implementation is not synchronized.</strong>
+ * If multiple threads access an <tt>ArrayList</tt> instance concurrently,
+ * and at least one of the threads modifies the list structurally, it
+ * <i>must</i> be synchronized externally. (A structural modification is
+ * any operation that adds or deletes one or more elements, or explicitly
+ * resizes the backing array; merely setting the value of an element is not
+ * a structural modification.) This is typically accomplished by
+ * synchronizing on some object that naturally encapsulates the list.
+ *
+ * If no such object exists, the list should be "wrapped" using the
+ * {@link Collections#synchronizedList Collections.synchronizedList}
+ * method. This is best done at creation time, to prevent accidental
+ * unsynchronized access to the list:<pre>
+ * List list = Collections.synchronizedList(new ArrayList(...));</pre>
+ *
+ * <p><a name="fail-fast"/>
+ * The iterators returned by this class's {@link #iterator() iterator} and
+ * {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:
+ * if the list is structurally modified at any time after the iterator is
+ * created, in any way except through the iterator's own
+ * {@link ListIterator#remove() remove} or
+ * {@link ListIterator#add(Object) add} methods, the iterator will throw a
+ * {@link ConcurrentModificationException}. Thus, in the face of
+ * concurrent modification, the iterator fails quickly and cleanly, rather
+ * than risking arbitrary, non-deterministic behavior at an undetermined
+ * time in the future.
+ *
+ * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
+ * as it is, generally speaking, impossible to make any hard guarantees in the
+ * presence of unsynchronized concurrent modification. Fail-fast iterators
+ * throw {@code ConcurrentModificationException} on a best-effort basis.
+ * Therefore, it would be wrong to write a program that depended on this
+ * exception for its correctness: <i>the fail-fast behavior of iterators
+ * should be used only to detect bugs.</i>
+ *
+ * <p>This class is a member of the
+ * <a href="{@docRoot}/../technotes/guides/collections/index.html">
+ * Java Collections Framework</a>.
+ *
+ * @author Josh Bloch
+ * @author Neal Gafter
+ * @see Collection
+ * @see List
+ * @see LinkedList
+ * @see Vector
+ * @since 1.2
+ */
+
+public class ArrayList<E> extends AbstractList<E>
+ implements List<E>, RandomAccess, Cloneable, java.io.Serializable
+{
+ private static final long serialVersionUID = 8683452581122892189L;
+
+ /**
+ * The array buffer into which the elements of the ArrayList are stored.
+ * The capacity of the ArrayList is the length of this array buffer.
+ */
+ private transient Object[] elementData;
+
+ /**
+ * The size of the ArrayList (the number of elements it contains).
+ *
+ * @serial
+ */
+ private int size;
+
+ /**
+ * Constructs an empty list with the specified initial capacity.
+ *
+ * @param initialCapacity the initial capacity of the list
+ * @exception IllegalArgumentException if the specified initial capacity
+ * is negative
+ */
+ public ArrayList(int initialCapacity) {
+ super();
+ if (initialCapacity < 0)
+ throw new IllegalArgumentException("Illegal Capacity: "+
+ initialCapacity);
+ this.elementData = new Object[initialCapacity];
+ }
+
+ /**
+ * Constructs an empty list with an initial capacity of ten.
+ */
+ public ArrayList() {
+ this(10);
+ }
+
+ /**
+ * Constructs a list containing the elements of the specified
+ * collection, in the order they are returned by the collection's
+ * iterator.
+ *
+ * @param c the collection whose elements are to be placed into this list
+ * @throws NullPointerException if the specified collection is null
+ */
+ public ArrayList(Collection<? extends E> c) {
+ elementData = c.toArray();
+ size = elementData.length;
+ // c.toArray might (incorrectly) not return Object[] (see 6260652)
+ if (elementData.getClass() != Object[].class)
+ elementData = Arrays.copyOf(elementData, size, Object[].class);
+ }
+
+ /**
+ * Trims the capacity of this <tt>ArrayList</tt> instance to be the
+ * list's current size. An application can use this operation to minimize
+ * the storage of an <tt>ArrayList</tt> instance.
+ */
+ public void trimToSize() {
+ modCount++;
+ int oldCapacity = elementData.length;
+ if (size < oldCapacity) {
+ elementData = Arrays.copyOf(elementData, size);
+ }
+ }
+
+ /**
+ * Increases the capacity of this <tt>ArrayList</tt> instance, if
+ * necessary, to ensure that it can hold at least the number of elements
+ * specified by the minimum capacity argument.
+ *
+ * @param minCapacity the desired minimum capacity
+ */
+ public void ensureCapacity(int minCapacity) {
+ modCount++;
+ int oldCapacity = elementData.length;
+ if (minCapacity > oldCapacity) {
+ Object oldData[] = elementData;
+ int newCapacity = (oldCapacity * 3)/2 + 1;
+ if (newCapacity < minCapacity)
+ newCapacity = minCapacity;
+ // minCapacity is usually close to size, so this is a win:
+ elementData = Arrays.copyOf(elementData, newCapacity);
+ }
+ }
+
+ /**
+ * Returns the number of elements in this list.
+ *
+ * @return the number of elements in this list
+ */
+ public int size() {
+ return size;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this list contains no elements.
+ *
+ * @return <tt>true</tt> if this list contains no elements
+ */
+ public boolean isEmpty() {
+ return size == 0;
+ }
+
+ /**
+ * Returns <tt>true</tt> if this list contains the specified element.
+ * More formally, returns <tt>true</tt> if and only if this list contains
+ * at least one element <tt>e</tt> such that
+ * <tt>(o==null ? e==null : o.equals(e))</tt>.
+ *
+ * @param o element whose presence in this list is to be tested
+ * @return <tt>true</tt> if this list contains the specified element
+ */
+ public boolean contains(Object o) {
+ return indexOf(o) >= 0;
+ }
+
+ /**
+ * Returns the index of the first occurrence of the specified element
+ * in this list, or -1 if this list does not contain the element.
+ * More formally, returns the lowest index <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
+ * or -1 if there is no such index.
+ */
+ public int indexOf(Object o) {
+ if (o == null) {
+ for (int i = 0; i < size; i++)
+ if (elementData[i]==null)
+ return i;
+ } else {
+ for (int i = 0; i < size; i++)
+ if (o.equals(elementData[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ /**
+ * Returns the index of the last occurrence of the specified element
+ * in this list, or -1 if this list does not contain the element.
+ * More formally, returns the highest index <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
+ * or -1 if there is no such index.
+ */
+ public int lastIndexOf(Object o) {
+ if (o == null) {
+ for (int i = size-1; i >= 0; i--)
+ if (elementData[i]==null)
+ return i;
+ } else {
+ for (int i = size-1; i >= 0; i--)
+ if (o.equals(elementData[i]))
+ return i;
+ }
+ return -1;
+ }
+
+ /**
+ * Returns a shallow copy of this <tt>ArrayList</tt> instance. (The
+ * elements themselves are not copied.)
+ *
+ * @return a clone of this <tt>ArrayList</tt> instance
+ */
+ public Object clone() {
+ try {
+ @SuppressWarnings("unchecked")
+ ArrayList<E> v = (ArrayList<E>) super.clone();
+ v.elementData = Arrays.copyOf(elementData, size);
+ v.modCount = 0;
+ return v;
+ } catch (CloneNotSupportedException e) {
+ // this shouldn't happen, since we are Cloneable
+ throw new InternalError();
+ }
+ }
+
+ /**
+ * Returns an array containing all of the elements in this list
+ * in proper sequence (from first to last element).
+ *
+ * <p>The returned array will be "safe" in that no references to it are
+ * maintained by this list. (In other words, this method must allocate
+ * a new array). The caller is thus free to modify the returned array.
+ *
+ * <p>This method acts as bridge between array-based and collection-based
+ * APIs.
+ *
+ * @return an array containing all of the elements in this list in
+ * proper sequence
+ */
+ public Object[] toArray() {
+ return Arrays.copyOf(elementData, size);
+ }
+
+ /**
+ * Returns an array containing all of the elements in this list in proper
+ * sequence (from first to last element); the runtime type of the returned
+ * array is that of the specified array. If the list fits in the
+ * specified array, it is returned therein. Otherwise, a new array is
+ * allocated with the runtime type of the specified array and the size of
+ * this list.
+ *
+ * <p>If the list fits in the specified array with room to spare
+ * (i.e., the array has more elements than the list), the element in
+ * the array immediately following the end of the collection is set to
+ * <tt>null</tt>. (This is useful in determining the length of the
+ * list <i>only</i> if the caller knows that the list does not contain
+ * any null elements.)
+ *
+ * @param a the array into which the elements of the list are to
+ * be stored, if it is big enough; otherwise, a new array of the
+ * same runtime type is allocated for this purpose.
+ * @return an array containing the elements of the list
+ * @throws ArrayStoreException if the runtime type of the specified array
+ * is not a supertype of the runtime type of every element in
+ * this list
+ * @throws NullPointerException if the specified array is null
+ */
+ @SuppressWarnings("unchecked")
+ public <T> T[] toArray(T[] a) {
+ if (a.length < size)
+ // Make a new array of a's runtime type, but my contents:
+ return (T[]) Arrays.copyOf(elementData, size, a.getClass());
+ System.arraycopy(elementData, 0, a, 0, size);
+ if (a.length > size)
+ a[size] = null;
+ return a;
+ }
+
+ // Positional Access Operations
+
+ @SuppressWarnings("unchecked")
+ E elementData(int index) {
+ return (E) elementData[index];
+ }
+
+ /**
+ * Returns the element at the specified position in this list.
+ *
+ * @param index index of the element to return
+ * @return the element at the specified position in this list
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public E get(int index) {
+ rangeCheck(index);
+
+ return elementData(index);
+ }
+
+ /**
+ * Replaces the element at the specified position in this list with
+ * the specified element.
+ *
+ * @param index index of the element to replace
+ * @param element element to be stored at the specified position
+ * @return the element previously at the specified position
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public E set(int index, E element) {
+ rangeCheck(index);
+
+ E oldValue = elementData(index);
+ elementData[index] = element;
+ return oldValue;
+ }
+
+ /**
+ * Appends the specified element to the end of this list.
+ *
+ * @param e element to be appended to this list
+ * @return <tt>true</tt> (as specified by {@link Collection#add})
+ */
+ public boolean add(E e) {
+ ensureCapacity(size + 1); // Increments modCount!!
+ elementData[size++] = e;
+ return true;
+ }
+
+ /**
+ * Inserts the specified element at the specified position in this
+ * list. Shifts the element currently at that position (if any) and
+ * any subsequent elements to the right (adds one to their indices).
+ *
+ * @param index index at which the specified element is to be inserted
+ * @param element element to be inserted
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public void add(int index, E element) {
+ rangeCheckForAdd(index);
+
+ ensureCapacity(size+1); // Increments modCount!!
+ System.arraycopy(elementData, index, elementData, index + 1,
+ size - index);
+ elementData[index] = element;
+ size++;
+ }
+
+ /**
+ * Removes the element at the specified position in this list.
+ * Shifts any subsequent elements to the left (subtracts one from their
+ * indices).
+ *
+ * @param index the index of the element to be removed
+ * @return the element that was removed from the list
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public E remove(int index) {
+ rangeCheck(index);
+
+ modCount++;
+ E oldValue = elementData(index);
+
+ int numMoved = size - index - 1;
+ if (numMoved > 0)
+ System.arraycopy(elementData, index+1, elementData, index,
+ numMoved);
+ elementData[--size] = null; // Let gc do its work
+
+ return oldValue;
+ }
+
+ /**
+ * Removes the first occurrence of the specified element from this list,
+ * if it is present. If the list does not contain the element, it is
+ * unchanged. More formally, removes the element with the lowest index
+ * <tt>i</tt> such that
+ * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>
+ * (if such an element exists). Returns <tt>true</tt> if this list
+ * contained the specified element (or equivalently, if this list
+ * changed as a result of the call).
+ *
+ * @param o element to be removed from this list, if present
+ * @return <tt>true</tt> if this list contained the specified element
+ */
+ public boolean remove(Object o) {
+ if (o == null) {
+ for (int index = 0; index < size; index++)
+ if (elementData[index] == null) {
+ fastRemove(index);
+ return true;
+ }
+ } else {
+ for (int index = 0; index < size; index++)
+ if (o.equals(elementData[index])) {
+ fastRemove(index);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /*
+ * Private remove method that skips bounds checking and does not
+ * return the value removed.
+ */
+ private void fastRemove(int index) {
+ modCount++;
+ int numMoved = size - index - 1;
+ if (numMoved > 0)
+ System.arraycopy(elementData, index+1, elementData, index,
+ numMoved);
+ elementData[--size] = null; // Let gc do its work
+ }
+
+ /**
+ * Removes all of the elements from this list. The list will
+ * be empty after this call returns.
+ */
+ public void clear() {
+ modCount++;
+
+ // Let gc do its work
+ for (int i = 0; i < size; i++)
+ elementData[i] = null;
+
+ size = 0;
+ }
+
+ /**
+ * Appends all of the elements in the specified collection to the end of
+ * this list, in the order that they are returned by the
+ * specified collection's Iterator. The behavior of this operation is
+ * undefined if the specified collection is modified while the operation
+ * is in progress. (This implies that the behavior of this call is
+ * undefined if the specified collection is this list, and this
+ * list is nonempty.)
+ *
+ * @param c collection containing elements to be added to this list
+ * @return <tt>true</tt> if this list changed as a result of the call
+ * @throws NullPointerException if the specified collection is null
+ */
+ public boolean addAll(Collection<? extends E> c) {
+ Object[] a = c.toArray();
+ int numNew = a.length;
+ ensureCapacity(size + numNew); // Increments modCount
+ System.arraycopy(a, 0, elementData, size, numNew);
+ size += numNew;
+ return numNew != 0;
+ }
+
+ /**
+ * Inserts all of the elements in the specified collection into this
+ * list, starting at the specified position. Shifts the element
+ * currently at that position (if any) and any subsequent elements to
+ * the right (increases their indices). The new elements will appear
+ * in the list in the order that they are returned by the
+ * specified collection's iterator.
+ *
+ * @param index index at which to insert the first element from the
+ * specified collection
+ * @param c collection containing elements to be added to this list
+ * @return <tt>true</tt> if this list changed as a result of the call
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ * @throws NullPointerException if the specified collection is null
+ */
+ public boolean addAll(int index, Collection<? extends E> c) {
+ rangeCheckForAdd(index);
+
+ Object[] a = c.toArray();
+ int numNew = a.length;
+ ensureCapacity(size + numNew); // Increments modCount
+
+ int numMoved = size - index;
+ if (numMoved > 0)
+ System.arraycopy(elementData, index, elementData, index + numNew,
+ numMoved);
+
+ System.arraycopy(a, 0, elementData, index, numNew);
+ size += numNew;
+ return numNew != 0;
+ }
+
+ /**
+ * Removes from this list all of the elements whose index is between
+ * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.
+ * Shifts any succeeding elements to the left (reduces their index).
+ * This call shortens the list by {@code (toIndex - fromIndex)} elements.
+ * (If {@code toIndex==fromIndex}, this operation has no effect.)
+ *
+ * @throws IndexOutOfBoundsException if {@code fromIndex} or
+ * {@code toIndex} is out of range
+ * ({@code fromIndex < 0 ||
+ * fromIndex >= size() ||
+ * toIndex > size() ||
+ * toIndex < fromIndex})
+ */
+ protected void removeRange(int fromIndex, int toIndex) {
+ modCount++;
+ int numMoved = size - toIndex;
+ System.arraycopy(elementData, toIndex, elementData, fromIndex,
+ numMoved);
+
+ // Let gc do its work
+ int newSize = size - (toIndex-fromIndex);
+ while (size != newSize)
+ elementData[--size] = null;
+ }
+
+ /**
+ * Checks if the given index is in range. If not, throws an appropriate
+ * runtime exception. This method does *not* check if the index is
+ * negative: It is always used immediately prior to an array access,
+ * which throws an ArrayIndexOutOfBoundsException if index is negative.
+ */
+ private void rangeCheck(int index) {
+ if (index >= size)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ /**
+ * A version of rangeCheck used by add and addAll.
+ */
+ private void rangeCheckForAdd(int index) {
+ if (index > size || index < 0)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ /**
+ * Constructs an IndexOutOfBoundsException detail message.
+ * Of the many possible refactorings of the error handling code,
+ * this "outlining" performs best with both server and client VMs.
+ */
+ private String outOfBoundsMsg(int index) {
+ return "Index: "+index+", Size: "+size;
+ }
+
+ /**
+ * Removes from this list all of its elements that are contained in the
+ * specified collection.
+ *
+ * @param c collection containing elements to be removed from this list
+ * @return {@code true} if this list changed as a result of the call
+ * @throws ClassCastException if the class of an element of this list
+ * is incompatible with the specified collection (optional)
+ * @throws NullPointerException if this list contains a null element and the
+ * specified collection does not permit null elements (optional),
+ * or if the specified collection is null
+ * @see Collection#contains(Object)
+ */
+ public boolean removeAll(Collection<?> c) {
+ return batchRemove(c, false);
+ }
+
+ /**
+ * Retains only the elements in this list that are contained in the
+ * specified collection. In other words, removes from this list all
+ * of its elements that are not contained in the specified collection.
+ *
+ * @param c collection containing elements to be retained in this list
+ * @return {@code true} if this list changed as a result of the call
+ * @throws ClassCastException if the class of an element of this list
+ * is incompatible with the specified collection (optional)
+ * @throws NullPointerException if this list contains a null element and the
+ * specified collection does not permit null elements (optional),
+ * or if the specified collection is null
+ * @see Collection#contains(Object)
+ */
+ public boolean retainAll(Collection<?> c) {
+ return batchRemove(c, true);
+ }
+
+ private boolean batchRemove(Collection<?> c, boolean complement) {
+ final Object[] elementData = this.elementData;
+ int r = 0, w = 0;
+ boolean modified = false;
+ try {
+ for (; r < size; r++)
+ if (c.contains(elementData[r]) == complement)
+ elementData[w++] = elementData[r];
+ } finally {
+ // Preserve behavioral compatibility with AbstractCollection,
+ // even if c.contains() throws.
+ if (r != size) {
+ System.arraycopy(elementData, r,
+ elementData, w,
+ size - r);
+ w += size - r;
+ }
+ if (w != size) {
+ for (int i = w; i < size; i++)
+ elementData[i] = null;
+ modCount += size - w;
+ size = w;
+ modified = true;
+ }
+ }
+ return modified;
+ }
+
+ /**
+ * Save the state of the <tt>ArrayList</tt> instance to a stream (that
+ * is, serialize it).
+ *
+ * @serialData The length of the array backing the <tt>ArrayList</tt>
+ * instance is emitted (int), followed by all of its elements
+ * (each an <tt>Object</tt>) in the proper order.
+ */
+ private void writeObject(java.io.ObjectOutputStream s)
+ throws java.io.IOException{
+ // Write out element count, and any hidden stuff
+ int expectedModCount = modCount;
+ s.defaultWriteObject();
+
+ // Write out array length
+ s.writeInt(elementData.length);
+
+ // Write out all elements in the proper order.
+ for (int i=0; i<size; i++)
+ s.writeObject(elementData[i]);
+
+ if (modCount != expectedModCount) {
+ throw new ConcurrentModificationException();
+ }
+
+ }
+
+ /**
+ * Reconstitute the <tt>ArrayList</tt> instance from a stream (that is,
+ * deserialize it).
+ */
+ private void readObject(java.io.ObjectInputStream s)
+ throws java.io.IOException, ClassNotFoundException {
+ // Read in size, and any hidden stuff
+ s.defaultReadObject();
+
+ // Read in array length and allocate array
+ int arrayLength = s.readInt();
+ Object[] a = elementData = new Object[arrayLength];
+
+ // Read in all elements in the proper order.
+ for (int i=0; i<size; i++)
+ a[i] = s.readObject();
+ }
+
+ /**
+ * Returns a list iterator over the elements in this list (in proper
+ * sequence), starting at the specified position in the list.
+ * The specified index indicates the first element that would be
+ * returned by an initial call to {@link ListIterator#next next}.
+ * An initial call to {@link ListIterator#previous previous} would
+ * return the element with the specified index minus one.
+ *
+ * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
+ *
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public ListIterator<E> listIterator(int index) {
+ if (index < 0 || index > size)
+ throw new IndexOutOfBoundsException("Index: "+index);
+ return new ListItr(index);
+ }
+
+ /**
+ * Returns a list iterator over the elements in this list (in proper
+ * sequence).
+ *
+ * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
+ *
+ * @see #listIterator(int)
+ */
+ public ListIterator<E> listIterator() {
+ return new ListItr(0);
+ }
+
+ /**
+ * Returns an iterator over the elements in this list in proper sequence.
+ *
+ * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
+ *
+ * @return an iterator over the elements in this list in proper sequence
+ */
+ public Iterator<E> iterator() {
+ return new Itr();
+ }
+
+ /**
+ * An optimized version of AbstractList.Itr
+ */
+ private class Itr implements Iterator<E> {
+ int cursor; // index of next element to return
+ int lastRet = -1; // index of last element returned; -1 if no such
+ int expectedModCount = modCount;
+
+ public boolean hasNext() {
+ return cursor != size;
+ }
+
+ @SuppressWarnings("unchecked")
+ public E next() {
+ checkForComodification();
+ int i = cursor;
+ if (i >= size)
+ throw new NoSuchElementException();
+ Object[] elementData = ArrayList.this.elementData;
+ if (i >= elementData.length)
+ throw new ConcurrentModificationException();
+ cursor = i + 1;
+ return (E) elementData[lastRet = i];
+ }
+
+ public void remove() {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ ArrayList.this.remove(lastRet);
+ cursor = lastRet;
+ lastRet = -1;
+ expectedModCount = modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ final void checkForComodification() {
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ /**
+ * An optimized version of AbstractList.ListItr
+ */
+ private class ListItr extends Itr implements ListIterator<E> {
+ ListItr(int index) {
+ super();
+ cursor = index;
+ }
+
+ public boolean hasPrevious() {
+ return cursor != 0;
+ }
+
+ public int nextIndex() {
+ return cursor;
+ }
+
+ public int previousIndex() {
+ return cursor - 1;
+ }
+
+ @SuppressWarnings("unchecked")
+ public E previous() {
+ checkForComodification();
+ int i = cursor - 1;
+ if (i < 0)
+ throw new NoSuchElementException();
+ Object[] elementData = ArrayList.this.elementData;
+ if (i >= elementData.length)
+ throw new ConcurrentModificationException();
+ cursor = i;
+ return (E) elementData[lastRet = i];
+ }
+
+ public void set(E e) {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ ArrayList.this.set(lastRet, e);
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ public void add(E e) {
+ checkForComodification();
+
+ try {
+ int i = cursor;
+ ArrayList.this.add(i, e);
+ cursor = i + 1;
+ lastRet = -1;
+ expectedModCount = modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+ }
+
+ /**
+ * Returns a view of the portion of this list between the specified
+ * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. (If
+ * {@code fromIndex} and {@code toIndex} are equal, the returned list is
+ * empty.) The returned list is backed by this list, so non-structural
+ * changes in the returned list are reflected in this list, and vice-versa.
+ * The returned list supports all of the optional list operations.
+ *
+ * <p>This method eliminates the need for explicit range operations (of
+ * the sort that commonly exist for arrays). Any operation that expects
+ * a list can be used as a range operation by passing a subList view
+ * instead of a whole list. For example, the following idiom
+ * removes a range of elements from a list:
+ * <pre>
+ * list.subList(from, to).clear();
+ * </pre>
+ * Similar idioms may be constructed for {@link #indexOf(Object)} and
+ * {@link #lastIndexOf(Object)}, and all of the algorithms in the
+ * {@link Collections} class can be applied to a subList.
+ *
+ * <p>The semantics of the list returned by this method become undefined if
+ * the backing list (i.e., this list) is <i>structurally modified</i> in
+ * any way other than via the returned list. (Structural modifications are
+ * those that change the size of this list, or otherwise perturb it in such
+ * a fashion that iterations in progress may yield incorrect results.)
+ *
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ * @throws IllegalArgumentException {@inheritDoc}
+ */
+ public List<E> subList(int fromIndex, int toIndex) {
+ subListRangeCheck(fromIndex, toIndex, size);
+ return new SubList(this, 0, fromIndex, toIndex);
+ }
+
+ static void subListRangeCheck(int fromIndex, int toIndex, int size) {
+ if (fromIndex < 0)
+ throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
+ if (toIndex > size)
+ throw new IndexOutOfBoundsException("toIndex = " + toIndex);
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException("fromIndex(" + fromIndex +
+ ") > toIndex(" + toIndex + ")");
+ }
+
+ private class SubList extends AbstractList<E> implements RandomAccess {
+ private final AbstractList<E> parent;
+ private final int parentOffset;
+ private final int offset;
+ private int size;
+
+ SubList(AbstractList<E> parent,
+ int offset, int fromIndex, int toIndex) {
+ this.parent = parent;
+ this.parentOffset = fromIndex;
+ this.offset = offset + fromIndex;
+ this.size = toIndex - fromIndex;
+ this.modCount = ArrayList.this.modCount;
+ }
+
+ public E set(int index, E e) {
+ rangeCheck(index);
+ checkForComodification();
+ E oldValue = ArrayList.this.elementData(offset + index);
+ ArrayList.this.elementData[offset + index] = e;
+ return oldValue;
+ }
+
+ public E get(int index) {
+ rangeCheck(index);
+ checkForComodification();
+ return ArrayList.this.elementData(offset + index);
+ }
+
+ public int size() {
+ checkForComodification();
+ return this.size;
+ }
+
+ public void add(int index, E e) {
+ rangeCheckForAdd(index);
+ checkForComodification();
+ parent.add(parentOffset + index, e);
+ this.modCount = parent.modCount;
+ this.size++;
+ }
+
+ public E remove(int index) {
+ rangeCheck(index);
+ checkForComodification();
+ E result = parent.remove(parentOffset + index);
+ this.modCount = parent.modCount;
+ this.size--;
+ return result;
+ }
+
+ protected void removeRange(int fromIndex, int toIndex) {
+ checkForComodification();
+ parent.removeRange(parentOffset + fromIndex,
+ parentOffset + toIndex);
+ this.modCount = parent.modCount;
+ this.size -= toIndex - fromIndex;
+ }
+
+ public boolean addAll(Collection<? extends E> c) {
+ return addAll(this.size, c);
+ }
+
+ public boolean addAll(int index, Collection<? extends E> c) {
+ rangeCheckForAdd(index);
+ int cSize = c.size();
+ if (cSize==0)
+ return false;
+
+ checkForComodification();
+ parent.addAll(parentOffset + index, c);
+ this.modCount = parent.modCount;
+ this.size += cSize;
+ return true;
+ }
+
+ public Iterator<E> iterator() {
+ return listIterator();
+ }
+
+ public ListIterator<E> listIterator(final int index) {
+ checkForComodification();
+ rangeCheckForAdd(index);
+
+ return new ListIterator<E>() {
+ int cursor = index;
+ int lastRet = -1;
+ int expectedModCount = ArrayList.this.modCount;
+
+ public boolean hasNext() {
+ return cursor != SubList.this.size;
+ }
+
+ @SuppressWarnings("unchecked")
+ public E next() {
+ checkForComodification();
+ int i = cursor;
+ if (i >= SubList.this.size)
+ throw new NoSuchElementException();
+ Object[] elementData = ArrayList.this.elementData;
+ if (offset + i >= elementData.length)
+ throw new ConcurrentModificationException();
+ cursor = i + 1;
+ return (E) elementData[offset + (lastRet = i)];
+ }
+
+ public boolean hasPrevious() {
+ return cursor != 0;
+ }
+
+ @SuppressWarnings("unchecked")
+ public E previous() {
+ checkForComodification();
+ int i = cursor - 1;
+ if (i < 0)
+ throw new NoSuchElementException();
+ Object[] elementData = ArrayList.this.elementData;
+ if (offset + i >= elementData.length)
+ throw new ConcurrentModificationException();
+ cursor = i;
+ return (E) elementData[offset + (lastRet = i)];
+ }
+
+ public int nextIndex() {
+ return cursor;
+ }
+
+ public int previousIndex() {
+ return cursor - 1;
+ }
+
+ public void remove() {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ SubList.this.remove(lastRet);
+ cursor = lastRet;
+ lastRet = -1;
+ expectedModCount = ArrayList.this.modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ public void set(E e) {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ ArrayList.this.set(offset + lastRet, e);
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ public void add(E e) {
+ checkForComodification();
+
+ try {
+ int i = cursor;
+ SubList.this.add(i, e);
+ cursor = i + 1;
+ lastRet = -1;
+ expectedModCount = ArrayList.this.modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ final void checkForComodification() {
+ if (expectedModCount != ArrayList.this.modCount)
+ throw new ConcurrentModificationException();
+ }
+ };
+ }
+
+ public List<E> subList(int fromIndex, int toIndex) {
+ subListRangeCheck(fromIndex, toIndex, size);
+ return new SubList(this, offset, fromIndex, toIndex);
+ }
+
+ private void rangeCheck(int index) {
+ if (index < 0 || index >= this.size)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ private void rangeCheckForAdd(int index) {
+ if (index < 0 || index > this.size)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ private String outOfBoundsMsg(int index) {
+ return "Index: "+index+", Size: "+this.size;
+ }
+
+ private void checkForComodification() {
+ if (ArrayList.this.modCount != this.modCount)
+ throw new ConcurrentModificationException();
+ }
+ }
+}