--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/AbstractList.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,782 @@
+/*
+ * 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;
+
+/**
+ * This class provides a skeletal implementation of the {@link List}
+ * interface to minimize the effort required to implement this interface
+ * backed by a "random access" data store (such as an array). For sequential
+ * access data (such as a linked list), {@link AbstractSequentialList} should
+ * be used in preference to this class.
+ *
+ * <p>To implement an unmodifiable list, the programmer needs only to extend
+ * this class and provide implementations for the {@link #get(int)} and
+ * {@link List#size() size()} methods.
+ *
+ * <p>To implement a modifiable list, the programmer must additionally
+ * override the {@link #set(int, Object) set(int, E)} method (which otherwise
+ * throws an {@code UnsupportedOperationException}). If the list is
+ * variable-size the programmer must additionally override the
+ * {@link #add(int, Object) add(int, E)} and {@link #remove(int)} methods.
+ *
+ * <p>The programmer should generally provide a void (no argument) and collection
+ * constructor, as per the recommendation in the {@link Collection} interface
+ * specification.
+ *
+ * <p>Unlike the other abstract collection implementations, the programmer does
+ * <i>not</i> have to provide an iterator implementation; the iterator and
+ * list iterator are implemented by this class, on top of the "random access"
+ * methods:
+ * {@link #get(int)},
+ * {@link #set(int, Object) set(int, E)},
+ * {@link #add(int, Object) add(int, E)} and
+ * {@link #remove(int)}.
+ *
+ * <p>The documentation for each non-abstract method in this class describes its
+ * implementation in detail. Each of these methods may be overridden if the
+ * collection being implemented admits a more efficient implementation.
+ *
+ * <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
+ * @since 1.2
+ */
+
+public abstract class AbstractList<E> extends AbstractCollection<E> implements List<E> {
+ /**
+ * Sole constructor. (For invocation by subclass constructors, typically
+ * implicit.)
+ */
+ protected AbstractList() {
+ }
+
+ /**
+ * Appends the specified element to the end of this list (optional
+ * operation).
+ *
+ * <p>Lists that support this operation may place limitations on what
+ * elements may be added to this list. In particular, some
+ * lists will refuse to add null elements, and others will impose
+ * restrictions on the type of elements that may be added. List
+ * classes should clearly specify in their documentation any restrictions
+ * on what elements may be added.
+ *
+ * <p>This implementation calls {@code add(size(), e)}.
+ *
+ * <p>Note that this implementation throws an
+ * {@code UnsupportedOperationException} unless
+ * {@link #add(int, Object) add(int, E)} is overridden.
+ *
+ * @param e element to be appended to this list
+ * @return {@code true} (as specified by {@link Collection#add})
+ * @throws UnsupportedOperationException if the {@code add} operation
+ * is not supported by this list
+ * @throws ClassCastException if the class of the specified element
+ * prevents it from being added to this list
+ * @throws NullPointerException if the specified element is null and this
+ * list does not permit null elements
+ * @throws IllegalArgumentException if some property of this element
+ * prevents it from being added to this list
+ */
+ public boolean add(E e) {
+ add(size(), e);
+ return true;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ abstract public E get(int index);
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation always throws an
+ * {@code UnsupportedOperationException}.
+ *
+ * @throws UnsupportedOperationException {@inheritDoc}
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException {@inheritDoc}
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public E set(int index, E element) {
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation always throws an
+ * {@code UnsupportedOperationException}.
+ *
+ * @throws UnsupportedOperationException {@inheritDoc}
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException {@inheritDoc}
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public void add(int index, E element) {
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation always throws an
+ * {@code UnsupportedOperationException}.
+ *
+ * @throws UnsupportedOperationException {@inheritDoc}
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public E remove(int index) {
+ throw new UnsupportedOperationException();
+ }
+
+
+ // Search Operations
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation first gets a list iterator (with
+ * {@code listIterator()}). Then, it iterates over the list until the
+ * specified element is found or the end of the list is reached.
+ *
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException {@inheritDoc}
+ */
+ public int indexOf(Object o) {
+ ListIterator<E> e = listIterator();
+ if (o==null) {
+ while (e.hasNext())
+ if (e.next()==null)
+ return e.previousIndex();
+ } else {
+ while (e.hasNext())
+ if (o.equals(e.next()))
+ return e.previousIndex();
+ }
+ return -1;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation first gets a list iterator that points to the end
+ * of the list (with {@code listIterator(size())}). Then, it iterates
+ * backwards over the list until the specified element is found, or the
+ * beginning of the list is reached.
+ *
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException {@inheritDoc}
+ */
+ public int lastIndexOf(Object o) {
+ ListIterator<E> e = listIterator(size());
+ if (o==null) {
+ while (e.hasPrevious())
+ if (e.previous()==null)
+ return e.nextIndex();
+ } else {
+ while (e.hasPrevious())
+ if (o.equals(e.previous()))
+ return e.nextIndex();
+ }
+ return -1;
+ }
+
+
+ // Bulk Operations
+
+ /**
+ * Removes all of the elements from this list (optional operation).
+ * The list will be empty after this call returns.
+ *
+ * <p>This implementation calls {@code removeRange(0, size())}.
+ *
+ * <p>Note that this implementation throws an
+ * {@code UnsupportedOperationException} unless {@code remove(int
+ * index)} or {@code removeRange(int fromIndex, int toIndex)} is
+ * overridden.
+ *
+ * @throws UnsupportedOperationException if the {@code clear} operation
+ * is not supported by this list
+ */
+ public void clear() {
+ removeRange(0, size());
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation gets an iterator over the specified collection
+ * and iterates over it, inserting the elements obtained from the
+ * iterator into this list at the appropriate position, one at a time,
+ * using {@code add(int, E)}.
+ * Many implementations will override this method for efficiency.
+ *
+ * <p>Note that this implementation throws an
+ * {@code UnsupportedOperationException} unless
+ * {@link #add(int, Object) add(int, E)} is overridden.
+ *
+ * @throws UnsupportedOperationException {@inheritDoc}
+ * @throws ClassCastException {@inheritDoc}
+ * @throws NullPointerException {@inheritDoc}
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public boolean addAll(int index, Collection<? extends E> c) {
+ rangeCheckForAdd(index);
+ boolean modified = false;
+ Iterator<? extends E> e = c.iterator();
+ while (e.hasNext()) {
+ add(index++, e.next());
+ modified = true;
+ }
+ return modified;
+ }
+
+
+ // Iterators
+
+ /**
+ * Returns an iterator over the elements in this list in proper sequence.
+ *
+ * <p>This implementation returns a straightforward implementation of the
+ * iterator interface, relying on the backing list's {@code size()},
+ * {@code get(int)}, and {@code remove(int)} methods.
+ *
+ * <p>Note that the iterator returned by this method will throw an
+ * {@link UnsupportedOperationException} in response to its
+ * {@code remove} method unless the list's {@code remove(int)} method is
+ * overridden.
+ *
+ * <p>This implementation can be made to throw runtime exceptions in the
+ * face of concurrent modification, as described in the specification
+ * for the (protected) {@link #modCount} field.
+ *
+ * @return an iterator over the elements in this list in proper sequence
+ */
+ public Iterator<E> iterator() {
+ return new Itr();
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation returns {@code listIterator(0)}.
+ *
+ * @see #listIterator(int)
+ */
+ public ListIterator<E> listIterator() {
+ return listIterator(0);
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation returns a straightforward implementation of the
+ * {@code ListIterator} interface that extends the implementation of the
+ * {@code Iterator} interface returned by the {@code iterator()} method.
+ * The {@code ListIterator} implementation relies on the backing list's
+ * {@code get(int)}, {@code set(int, E)}, {@code add(int, E)}
+ * and {@code remove(int)} methods.
+ *
+ * <p>Note that the list iterator returned by this implementation will
+ * throw an {@link UnsupportedOperationException} in response to its
+ * {@code remove}, {@code set} and {@code add} methods unless the
+ * list's {@code remove(int)}, {@code set(int, E)}, and
+ * {@code add(int, E)} methods are overridden.
+ *
+ * <p>This implementation can be made to throw runtime exceptions in the
+ * face of concurrent modification, as described in the specification for
+ * the (protected) {@link #modCount} field.
+ *
+ * @throws IndexOutOfBoundsException {@inheritDoc}
+ */
+ public ListIterator<E> listIterator(final int index) {
+ rangeCheckForAdd(index);
+
+ return new ListItr(index);
+ }
+
+ private class Itr implements Iterator<E> {
+ /**
+ * Index of element to be returned by subsequent call to next.
+ */
+ int cursor = 0;
+
+ /**
+ * Index of element returned by most recent call to next or
+ * previous. Reset to -1 if this element is deleted by a call
+ * to remove.
+ */
+ int lastRet = -1;
+
+ /**
+ * The modCount value that the iterator believes that the backing
+ * List should have. If this expectation is violated, the iterator
+ * has detected concurrent modification.
+ */
+ int expectedModCount = modCount;
+
+ public boolean hasNext() {
+ return cursor != size();
+ }
+
+ public E next() {
+ checkForComodification();
+ try {
+ int i = cursor;
+ E next = get(i);
+ lastRet = i;
+ cursor = i + 1;
+ return next;
+ } catch (IndexOutOfBoundsException e) {
+ checkForComodification();
+ throw new NoSuchElementException();
+ }
+ }
+
+ public void remove() {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ AbstractList.this.remove(lastRet);
+ if (lastRet < cursor)
+ cursor--;
+ lastRet = -1;
+ expectedModCount = modCount;
+ } catch (IndexOutOfBoundsException e) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ final void checkForComodification() {
+ if (modCount != expectedModCount)
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ private class ListItr extends Itr implements ListIterator<E> {
+ ListItr(int index) {
+ cursor = index;
+ }
+
+ public boolean hasPrevious() {
+ return cursor != 0;
+ }
+
+ public E previous() {
+ checkForComodification();
+ try {
+ int i = cursor - 1;
+ E previous = get(i);
+ lastRet = cursor = i;
+ return previous;
+ } catch (IndexOutOfBoundsException e) {
+ checkForComodification();
+ throw new NoSuchElementException();
+ }
+ }
+
+ public int nextIndex() {
+ return cursor;
+ }
+
+ public int previousIndex() {
+ return cursor-1;
+ }
+
+ public void set(E e) {
+ if (lastRet < 0)
+ throw new IllegalStateException();
+ checkForComodification();
+
+ try {
+ AbstractList.this.set(lastRet, e);
+ expectedModCount = modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ public void add(E e) {
+ checkForComodification();
+
+ try {
+ int i = cursor;
+ AbstractList.this.add(i, e);
+ lastRet = -1;
+ cursor = i + 1;
+ expectedModCount = modCount;
+ } catch (IndexOutOfBoundsException ex) {
+ throw new ConcurrentModificationException();
+ }
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation returns a list that subclasses
+ * {@code AbstractList}. The subclass stores, in private fields, the
+ * offset of the subList within the backing list, the size of the subList
+ * (which can change over its lifetime), and the expected
+ * {@code modCount} value of the backing list. There are two variants
+ * of the subclass, one of which implements {@code RandomAccess}.
+ * If this list implements {@code RandomAccess} the returned list will
+ * be an instance of the subclass that implements {@code RandomAccess}.
+ *
+ * <p>The subclass's {@code set(int, E)}, {@code get(int)},
+ * {@code add(int, E)}, {@code remove(int)}, {@code addAll(int,
+ * Collection)} and {@code removeRange(int, int)} methods all
+ * delegate to the corresponding methods on the backing abstract list,
+ * after bounds-checking the index and adjusting for the offset. The
+ * {@code addAll(Collection c)} method merely returns {@code addAll(size,
+ * c)}.
+ *
+ * <p>The {@code listIterator(int)} method returns a "wrapper object"
+ * over a list iterator on the backing list, which is created with the
+ * corresponding method on the backing list. The {@code iterator} method
+ * merely returns {@code listIterator()}, and the {@code size} method
+ * merely returns the subclass's {@code size} field.
+ *
+ * <p>All methods first check to see if the actual {@code modCount} of
+ * the backing list is equal to its expected value, and throw a
+ * {@code ConcurrentModificationException} if it is not.
+ *
+ * @throws IndexOutOfBoundsException if an endpoint index value is out of range
+ * {@code (fromIndex < 0 || toIndex > size)}
+ * @throws IllegalArgumentException if the endpoint indices are out of order
+ * {@code (fromIndex > toIndex)}
+ */
+ public List<E> subList(int fromIndex, int toIndex) {
+ return (this instanceof RandomAccess ?
+ new RandomAccessSubList<E>(this, fromIndex, toIndex) :
+ new SubList<E>(this, fromIndex, toIndex));
+ }
+
+ // Comparison and hashing
+
+ /**
+ * Compares the specified object with this list for equality. Returns
+ * {@code true} if and only if the specified object is also a list, both
+ * lists have the same size, and all corresponding pairs of elements in
+ * the two lists are <i>equal</i>. (Two elements {@code e1} and
+ * {@code e2} are <i>equal</i> if {@code (e1==null ? e2==null :
+ * e1.equals(e2))}.) In other words, two lists are defined to be
+ * equal if they contain the same elements in the same order.<p>
+ *
+ * This implementation first checks if the specified object is this
+ * list. If so, it returns {@code true}; if not, it checks if the
+ * specified object is a list. If not, it returns {@code false}; if so,
+ * it iterates over both lists, comparing corresponding pairs of elements.
+ * If any comparison returns {@code false}, this method returns
+ * {@code false}. If either iterator runs out of elements before the
+ * other it returns {@code false} (as the lists are of unequal length);
+ * otherwise it returns {@code true} when the iterations complete.
+ *
+ * @param o the object to be compared for equality with this list
+ * @return {@code true} if the specified object is equal to this list
+ */
+ public boolean equals(Object o) {
+ if (o == this)
+ return true;
+ if (!(o instanceof List))
+ return false;
+
+ ListIterator<E> e1 = listIterator();
+ ListIterator e2 = ((List) o).listIterator();
+ while(e1.hasNext() && e2.hasNext()) {
+ E o1 = e1.next();
+ Object o2 = e2.next();
+ if (!(o1==null ? o2==null : o1.equals(o2)))
+ return false;
+ }
+ return !(e1.hasNext() || e2.hasNext());
+ }
+
+ /**
+ * Returns the hash code value for this list.
+ *
+ * <p>This implementation uses exactly the code that is used to define the
+ * list hash function in the documentation for the {@link List#hashCode}
+ * method.
+ *
+ * @return the hash code value for this list
+ */
+ public int hashCode() {
+ int hashCode = 1;
+ for (E e : this)
+ hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
+ return hashCode;
+ }
+
+ /**
+ * 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.)
+ *
+ * <p>This method is called by the {@code clear} operation on this list
+ * and its subLists. Overriding this method to take advantage of
+ * the internals of the list implementation can <i>substantially</i>
+ * improve the performance of the {@code clear} operation on this list
+ * and its subLists.
+ *
+ * <p>This implementation gets a list iterator positioned before
+ * {@code fromIndex}, and repeatedly calls {@code ListIterator.next}
+ * followed by {@code ListIterator.remove} until the entire range has
+ * been removed. <b>Note: if {@code ListIterator.remove} requires linear
+ * time, this implementation requires quadratic time.</b>
+ *
+ * @param fromIndex index of first element to be removed
+ * @param toIndex index after last element to be removed
+ */
+ protected void removeRange(int fromIndex, int toIndex) {
+ ListIterator<E> it = listIterator(fromIndex);
+ for (int i=0, n=toIndex-fromIndex; i<n; i++) {
+ it.next();
+ it.remove();
+ }
+ }
+
+ /**
+ * The number of times this list has been <i>structurally modified</i>.
+ * Structural modifications are those that change the size of the
+ * list, or otherwise perturb it in such a fashion that iterations in
+ * progress may yield incorrect results.
+ *
+ * <p>This field is used by the iterator and list iterator implementation
+ * returned by the {@code iterator} and {@code listIterator} methods.
+ * If the value of this field changes unexpectedly, the iterator (or list
+ * iterator) will throw a {@code ConcurrentModificationException} in
+ * response to the {@code next}, {@code remove}, {@code previous},
+ * {@code set} or {@code add} operations. This provides
+ * <i>fail-fast</i> behavior, rather than non-deterministic behavior in
+ * the face of concurrent modification during iteration.
+ *
+ * <p><b>Use of this field by subclasses is optional.</b> If a subclass
+ * wishes to provide fail-fast iterators (and list iterators), then it
+ * merely has to increment this field in its {@code add(int, E)} and
+ * {@code remove(int)} methods (and any other methods that it overrides
+ * that result in structural modifications to the list). A single call to
+ * {@code add(int, E)} or {@code remove(int)} must add no more than
+ * one to this field, or the iterators (and list iterators) will throw
+ * bogus {@code ConcurrentModificationExceptions}. If an implementation
+ * does not wish to provide fail-fast iterators, this field may be
+ * ignored.
+ */
+ protected transient int modCount = 0;
+
+ private void rangeCheckForAdd(int index) {
+ if (index < 0 || index > size())
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ private String outOfBoundsMsg(int index) {
+ return "Index: "+index+", Size: "+size();
+ }
+}
+
+class SubList<E> extends AbstractList<E> {
+ private final AbstractList<E> l;
+ private final int offset;
+ private int size;
+
+ SubList(AbstractList<E> list, int fromIndex, int toIndex) {
+ if (fromIndex < 0)
+ throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
+ if (toIndex > list.size())
+ throw new IndexOutOfBoundsException("toIndex = " + toIndex);
+ if (fromIndex > toIndex)
+ throw new IllegalArgumentException("fromIndex(" + fromIndex +
+ ") > toIndex(" + toIndex + ")");
+ l = list;
+ offset = fromIndex;
+ size = toIndex - fromIndex;
+ this.modCount = l.modCount;
+ }
+
+ public E set(int index, E element) {
+ rangeCheck(index);
+ checkForComodification();
+ return l.set(index+offset, element);
+ }
+
+ public E get(int index) {
+ rangeCheck(index);
+ checkForComodification();
+ return l.get(index+offset);
+ }
+
+ public int size() {
+ checkForComodification();
+ return size;
+ }
+
+ public void add(int index, E element) {
+ rangeCheckForAdd(index);
+ checkForComodification();
+ l.add(index+offset, element);
+ this.modCount = l.modCount;
+ size++;
+ }
+
+ public E remove(int index) {
+ rangeCheck(index);
+ checkForComodification();
+ E result = l.remove(index+offset);
+ this.modCount = l.modCount;
+ size--;
+ return result;
+ }
+
+ protected void removeRange(int fromIndex, int toIndex) {
+ checkForComodification();
+ l.removeRange(fromIndex+offset, toIndex+offset);
+ this.modCount = l.modCount;
+ size -= (toIndex-fromIndex);
+ }
+
+ public boolean addAll(Collection<? extends E> c) {
+ return addAll(size, c);
+ }
+
+ public boolean addAll(int index, Collection<? extends E> c) {
+ rangeCheckForAdd(index);
+ int cSize = c.size();
+ if (cSize==0)
+ return false;
+
+ checkForComodification();
+ l.addAll(offset+index, c);
+ this.modCount = l.modCount;
+ size += cSize;
+ return true;
+ }
+
+ public Iterator<E> iterator() {
+ return listIterator();
+ }
+
+ public ListIterator<E> listIterator(final int index) {
+ checkForComodification();
+ rangeCheckForAdd(index);
+
+ return new ListIterator<E>() {
+ private final ListIterator<E> i = l.listIterator(index+offset);
+
+ public boolean hasNext() {
+ return nextIndex() < size;
+ }
+
+ public E next() {
+ if (hasNext())
+ return i.next();
+ else
+ throw new NoSuchElementException();
+ }
+
+ public boolean hasPrevious() {
+ return previousIndex() >= 0;
+ }
+
+ public E previous() {
+ if (hasPrevious())
+ return i.previous();
+ else
+ throw new NoSuchElementException();
+ }
+
+ public int nextIndex() {
+ return i.nextIndex() - offset;
+ }
+
+ public int previousIndex() {
+ return i.previousIndex() - offset;
+ }
+
+ public void remove() {
+ i.remove();
+ SubList.this.modCount = l.modCount;
+ size--;
+ }
+
+ public void set(E e) {
+ i.set(e);
+ }
+
+ public void add(E e) {
+ i.add(e);
+ SubList.this.modCount = l.modCount;
+ size++;
+ }
+ };
+ }
+
+ public List<E> subList(int fromIndex, int toIndex) {
+ return new SubList<E>(this, fromIndex, toIndex);
+ }
+
+ private void rangeCheck(int index) {
+ if (index < 0 || index >= size)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ private void rangeCheckForAdd(int index) {
+ if (index < 0 || index > size)
+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+ }
+
+ private String outOfBoundsMsg(int index) {
+ return "Index: "+index+", Size: "+size;
+ }
+
+ private void checkForComodification() {
+ if (this.modCount != l.modCount)
+ throw new ConcurrentModificationException();
+ }
+}
+
+class RandomAccessSubList<E> extends SubList<E> implements RandomAccess {
+ RandomAccessSubList(AbstractList<E> list, int fromIndex, int toIndex) {
+ super(list, fromIndex, toIndex);
+ }
+
+ public List<E> subList(int fromIndex, int toIndex) {
+ return new RandomAccessSubList<E>(this, fromIndex, toIndex);
+ }
+}