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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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|
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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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* @param c the collection whose elements are to be placed into this list |
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* @throws NullPointerException if the specified collection is null |
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*/ |
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public LinkedList(Collection<? extends E> c) { |
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this(); |
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addAll(c); |
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} |
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public LinkedList(Collection<? extends E> c) { |
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this(); |
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addAll(c); |
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} |
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|
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/** |
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* Returns the first element in this list. |
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} |
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|
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/** |
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* Inserts the given element at the beginning of this list. |
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* Inserts the specified element at the beginning of this list. |
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* |
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* @param e the element to be inserted at the beginning of this list |
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* @param e the element to add |
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*/ |
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public void addFirst(E e) { |
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addBefore(e, header.next); |
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} |
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|
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/** |
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* Appends the given element to the end of this list. (Identical in |
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* function to the <tt>add</tt> method; included only for consistency.) |
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* Appends the specified element to the end of this list. |
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* |
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* @param e the element to be inserted at the end of this list |
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* <p>This method is equivalent to {@link #add}. |
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* |
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* @param e the element to add |
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*/ |
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public void addLast(E e) { |
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addBefore(e, header); |
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/** |
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* Appends the specified element to the end of this list. |
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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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* this list, in the order that they are returned by the specified |
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* collection's iterator. The behavior of this operation is undefined if |
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* the specified collection is modified while the operation is in |
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* progress. (This implies that the behavior of this call is undefined if |
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* the specified Collection is this list, and this list is nonempty.) |
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* progress. (Note that this will occur if the specified collection is |
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* this list, and it's nonempty.) |
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* |
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* @param c the elements to be inserted into this list |
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* @param c collection containing elements to be added to this list |
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* @return <tt>true</tt> if this list changed as a result of the call |
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* @throws NullPointerException if the specified collection is null |
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*/ |
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* |
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* @param index index at which to insert the first element |
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* from the specified collection |
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* @param c elements to be inserted into this list |
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* @param c collection containing elements to be added to this list |
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* @return <tt>true</tt> if this list changed as a result of the call |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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* @throws NullPointerException if the specified collection is null |
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// Search Operations |
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|
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/** |
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* Returns the index in this list of the first occurrence of the |
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* specified element, or -1 if the List does not contain this |
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* element. More formally, returns the lowest index i such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, or -1 if |
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* there is no such index. |
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* Returns the index of the first occurrence of the specified element |
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* in this list, or -1 if this list does not contain the element. |
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* More formally, returns the lowest index <tt>i</tt> such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
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* or -1 if there is no such index. |
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* |
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* @param o element to search for |
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* @return the index in this list of the first occurrence of the |
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* specified element, or -1 if the list does not contain this |
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* element |
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* @return the index of the first occurrence of the specified element in |
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* this list, or -1 if this list does not contain the element |
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*/ |
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public int indexOf(Object o) { |
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int index = 0; |
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} |
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|
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/** |
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* Returns the index in this list of the last occurrence of the |
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* specified element, or -1 if the list does not contain this |
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* element. More formally, returns the highest index i such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, or -1 if |
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* there is no such index. |
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> |
* Returns the index of the last occurrence of the specified element |
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* in this list, or -1 if this list does not contain the element. |
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* More formally, returns the highest index <tt>i</tt> such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
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* or -1 if there is no such index. |
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* |
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* @param o element to search for |
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* @return the index in this list of the last occurrence of the |
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* specified element, or -1 if the list does not contain this |
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* element |
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* @return the index of the last occurrence of the specified element in |
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* this list, or -1 if this list does not contain the element |
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*/ |
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public int lastIndexOf(Object o) { |
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int index = size; |
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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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/** |
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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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/** |
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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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public boolean removeLastOccurrence(Object o) { |
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if (o==null) { |
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< |
for (Entry e = header.previous; e != header; e = e.previous) { |
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> |
for (Entry<E> e = header.previous; e != header; e = e.previous) { |
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if (e.element==null) { |
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remove(e); |
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return true; |
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} |
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} |
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} else { |
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< |
for (Entry e = header.previous; e != header; e = e.previous) { |
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> |
for (Entry<E> e = header.previous; e != header; e = e.previous) { |
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if (o.equals(e.element)) { |
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remove(e); |
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return true; |
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} |
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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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+ |
/** |
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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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* |
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|
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/** |
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* Returns an array containing all of the elements in this list |
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< |
* in the correct order. |
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* in proper sequence (from first to last element). |
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> |
* |
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* <p>The returned array will be "safe" in that no references to it are |
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* maintained by this list. (In other words, this method must allocate |
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> |
* a new array). The caller is thus free to modify the returned array. |
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> |
* |
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* <p>This method acts as bridge between array-based and collection-based |
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* APIs. |
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* |
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* @return an array containing all of the elements in this list |
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< |
* in the correct order |
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> |
* in proper sequence |
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*/ |
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public Object[] toArray() { |
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Object[] result = new Object[size]; |
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|
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/** |
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* Returns an array containing all of the elements in this list in |
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< |
* the correct order; the runtime type of the returned array is that of |
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< |
* the specified array. If the list fits in the specified array, it |
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< |
* is returned therein. Otherwise, a new array is allocated with the |
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< |
* runtime type of the specified array and the size of this list.<p> |
| 876 |
< |
* |
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< |
* If the list fits in the specified array with room to spare |
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< |
* (i.e., the array has more elements than the list), |
| 879 |
< |
* the element in the array immediately following the end of the |
| 880 |
< |
* collection is set to null. This is useful in determining the length |
| 881 |
< |
* of the list <i>only</i> if the caller knows that the list |
| 882 |
< |
* does not contain any null elements. |
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> |
* proper sequence (from first to last element); the runtime type of |
| 873 |
> |
* the returned array is that of the specified array. If the list fits |
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> |
* in the specified array, it is returned therein. Otherwise, a new |
| 875 |
> |
* array is allocated with the runtime type of the specified array and |
| 876 |
> |
* the size of this list. |
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> |
* |
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> |
* <p>If the list fits in the specified array with room to spare (i.e., |
| 879 |
> |
* the array has more elements than the list), the element in the array |
| 880 |
> |
* immediately following the end of the list is set to <tt>null</tt>. |
| 881 |
> |
* (This is useful in determining the length of the list <i>only</i> if |
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> |
* the caller knows that the list does not contain any null elements.) |
| 883 |
> |
* |
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> |
* <p>Like the {@link #toArray()} method, this method acts as bridge between |
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> |
* array-based and collection-based APIs. Further, this method allows |
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> |
* precise control over the runtime type of the output array, and may, |
| 887 |
> |
* under certain circumstances, be used to save allocation costs. |
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> |
* |
| 889 |
> |
* <p>Suppose <tt>x</tt> is a list known to contain only strings. |
| 890 |
> |
* The following code can be used to dump the list into a newly |
| 891 |
> |
* allocated array of <tt>String</tt>: |
| 892 |
> |
* |
| 893 |
> |
* <pre> |
| 894 |
> |
* String[] y = x.toArray(new String[0]);</pre> |
| 895 |
> |
* |
| 896 |
> |
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
| 897 |
> |
* <tt>toArray()</tt>. |
| 898 |
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* |
| 899 |
|
* @param a the array into which the elements of the list are to |
| 900 |
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* be stored, if it is big enough; otherwise, a new array of the |
| 901 |
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* same runtime type is allocated for this purpose. |
| 902 |
|
* @return an array containing the elements of the list |
| 903 |
< |
* @throws ArrayStoreException if the runtime type of a is not a |
| 904 |
< |
* supertype of the runtime type of every element in this list |
| 903 |
> |
* @throws ArrayStoreException if the runtime type of the specified array |
| 904 |
> |
* is not a supertype of the runtime type of every element in |
| 905 |
> |
* this list |
| 906 |
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* @throws NullPointerException if the specified array is null |
| 907 |
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*/ |
| 908 |
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public <T> T[] toArray(T[] a) { |
