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/* |
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* %W% %E% |
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* |
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* Copyright 2005 Sun Microsystems, Inc. All rights reserved. |
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* Copyright 2006 Sun Microsystems, Inc. All rights reserved. |
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* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
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*/ |
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package java.util; |
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import java.util.*; // for javadoc |
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import java.util.*; // for javadoc (till 6280605 is fixed) |
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/** |
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* Linked list implementation of the <tt>List</tt> interface. Implements all |
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* list. Operations that index into the list will traverse the list from |
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* the beginning or the end, whichever is closer to the specified index.<p> |
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* |
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* <b>Note that this implementation is not synchronized.</b> If multiple |
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* threads access a list concurrently, and at least one of the threads |
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* modifies the list structurally, it <i>must</i> be synchronized |
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* externally. (A structural modification is any operation that adds or |
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* deletes one or more elements; merely setting the value of an element is not |
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* a structural modification.) This is typically accomplished by |
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* synchronizing on some object that naturally encapsulates the list. If no |
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* such object exists, the list should be "wrapped" using the |
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* Collections.synchronizedList method. This is best done at creation time, |
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* to prevent accidental unsynchronized access to the list: <pre> |
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* List list = Collections.synchronizedList(new LinkedList(...)); |
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* </pre> |
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* <p><strong>Note that this implementation is not synchronized.</strong> |
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* If multiple threads access a linked list concurrently, and at least |
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* one of the threads modifies the list structurally, it <i>must</i> be |
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* synchronized externally. (A structural modification is any operation |
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* that adds or deletes one or more elements; merely setting the value of |
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* an element is not a structural modification.) This is typically |
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* accomplished by synchronizing on some object that naturally |
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* encapsulates the list. |
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* |
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* If no such object exists, the list should be "wrapped" using the |
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* {@link Collections#synchronizedList Collections.synchronizedList} |
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* method. This is best done at creation time, to prevent accidental |
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* unsynchronized access to the list:<pre> |
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* List list = Collections.synchronizedList(new LinkedList(...));</pre> |
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* |
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* <p>The iterators returned by this class's <tt>iterator</tt> and |
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* <tt>listIterator</tt> methods are <i>fail-fast</i>: if the list is |
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* @see List |
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* @see ArrayList |
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* @see Vector |
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* @see Collections#synchronizedList(List) |
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* @since 1.2 |
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* @param <E> the type of elements held in this collection |
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*/ |
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* <p>This method is equivalent to {@link #addLast}. |
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* |
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* @param e element to be appended to this list |
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* @return <tt>true</tt> (as per the spec for {@link Collection#add}) |
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* @return <tt>true</tt> (as specified by {@link Collection#add}) |
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*/ |
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public boolean add(E e) { |
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addBefore(e, header); |
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* Adds the specified element as the tail (last element) of this list. |
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* |
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* @param e the element to add |
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* @return <tt>true</tt> (as per the spec for {@link Queue#offer}) |
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* @return <tt>true</tt> (as specified by {@link Queue#offer}) |
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* @since 1.5 |
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*/ |
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public boolean offer(E e) { |
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* Inserts the specified element at the front of this list. |
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* |
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* @param e the element to insert |
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* @return <tt>true</tt> (as per the spec for {@link Deque#offerFirst}) |
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* @return <tt>true</tt> (as specified by {@link Deque#offerFirst}) |
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* @since 1.6 |
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*/ |
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public boolean offerFirst(E e) { |
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* Inserts the specified element at the end of this list. |
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* |
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* @param e the element to insert |
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* @return <tt>true</tt> (as per the spec for {@link Deque#offerLast}) |
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* @return <tt>true</tt> (as specified by {@link Deque#offerLast}) |
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* @since 1.6 |
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*/ |
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public boolean offerLast(E e) { |
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} |
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/** |
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* Retrieves and removes the first element of this list, or |
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* <tt>null</tt> if this list is empty. |
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* Retrieves and removes the first element of this list, |
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* or returns <tt>null</tt> if this list is empty. |
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* |
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* @return the first element of this list, or <tt>null</tt> if |
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* this list is empty |
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} |
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/** |
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* Retrieves and removes the last element of this list, or |
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* <tt>null</tt> if this list is empty. |
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* Retrieves and removes the last element of this list, |
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* or returns <tt>null</tt> if this list is empty. |
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* |
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* @return the last element of this list, or <tt>null</tt> if |
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* this list is empty |
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} |
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/** |
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* @since 1.6 |
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*/ |
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public Iterator<E> descendingIterator() { |
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return new DescendingIterator(); |
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} |
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|
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/** Adapter to provide descending iterators via ListItr.previous */ |
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private class DescendingIterator implements Iterator { |
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final ListItr itr = new ListItr(size()); |
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public boolean hasNext() { |
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return itr.hasPrevious(); |
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} |
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public E next() { |
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return itr.previous(); |
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} |
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public void remove() { |
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itr.remove(); |
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} |
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} |
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/** |
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* Returns a shallow copy of this <tt>LinkedList</tt>. (The elements |
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* themselves are not cloned.) |
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* |
