-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
0 parents
commit 7494c76
Showing
364 changed files
with
211,998 additions
and
0 deletions.
There are no files selected for viewing
Large diffs are not rendered by default.
Oops, something went wrong.
Large diffs are not rendered by default.
Oops, something went wrong.
Large diffs are not rendered by default.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,192 @@ | ||
/* | ||
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
*/ | ||
|
||
/* | ||
* | ||
* | ||
* | ||
* | ||
* | ||
* Written by Doug Lea with assistance from members of JCP JSR-166 | ||
* Expert Group and released to the public domain, as explained at | ||
* http:https://creativecommons.org/publicdomain/zero/1.0/ | ||
*/ | ||
|
||
package java.util; | ||
|
||
/** | ||
* This class provides skeletal implementations of some {@link Queue} | ||
* operations. The implementations in this class are appropriate when | ||
* the base implementation does <em>not</em> allow <tt>null</tt> | ||
* elements. Methods {@link #add add}, {@link #remove remove}, and | ||
* {@link #element element} are based on {@link #offer offer}, {@link | ||
* #poll poll}, and {@link #peek peek}, respectively, but throw | ||
* exceptions instead of indicating failure via <tt>false</tt> or | ||
* <tt>null</tt> returns. | ||
* | ||
* <p>A <tt>Queue</tt> implementation that extends this class must | ||
* minimally define a method {@link Queue#offer} which does not permit | ||
* insertion of <tt>null</tt> elements, along with methods {@link | ||
* Queue#peek}, {@link Queue#poll}, {@link Collection#size}, and | ||
* {@link Collection#iterator}. Typically, additional methods will be | ||
* overridden as well. If these requirements cannot be met, consider | ||
* instead subclassing {@link AbstractCollection}. | ||
* | ||
* <p>This class is a member of the | ||
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> | ||
* Java Collections Framework</a>. | ||
* | ||
* @since 1.5 | ||
* @author Doug Lea | ||
* @param <E> the type of elements held in this collection | ||
*/ | ||
public abstract class AbstractQueue<E> | ||
extends AbstractCollection<E> | ||
implements Queue<E> { | ||
|
||
/** | ||
* Constructor for use by subclasses. | ||
*/ | ||
protected AbstractQueue() { | ||
} | ||
|
||
/** | ||
* Inserts the specified element into this queue if it is possible to do so | ||
* immediately without violating capacity restrictions, returning | ||
* <tt>true</tt> upon success and throwing an <tt>IllegalStateException</tt> | ||
* if no space is currently available. | ||
* | ||
* <p>This implementation returns <tt>true</tt> if <tt>offer</tt> succeeds, | ||
* else throws an <tt>IllegalStateException</tt>. | ||
* | ||
* @param e the element to add | ||
* @return <tt>true</tt> (as specified by {@link Collection#add}) | ||
* @throws IllegalStateException if the element cannot be added at this | ||
* time due to capacity restrictions | ||
* @throws ClassCastException if the class of the specified element | ||
* prevents it from being added to this queue | ||
* @throws NullPointerException if the specified element is null and | ||
* this queue does not permit null elements | ||
* @throws IllegalArgumentException if some property of this element | ||
* prevents it from being added to this queue | ||
*/ | ||
public boolean add(E e) { | ||
if (offer(e)) | ||
return true; | ||
else | ||
throw new IllegalStateException("Queue full"); | ||
} | ||
|
||
/** | ||
* Retrieves and removes the head of this queue. This method differs | ||
* from {@link #poll poll} only in that it throws an exception if this | ||
* queue is empty. | ||
* | ||
* <p>This implementation returns the result of <tt>poll</tt> | ||
* unless the queue is empty. | ||
* | ||
* @return the head of this queue | ||
* @throws NoSuchElementException if this queue is empty | ||
*/ | ||
public E remove() { | ||
E x = poll(); | ||
if (x != null) | ||
return x; | ||
else | ||
throw new NoSuchElementException(); | ||
} | ||
|
||
/** | ||
* Retrieves, but does not remove, the head of this queue. This method | ||
* differs from {@link #peek peek} only in that it throws an exception if | ||
* this queue is empty. | ||
* | ||
* <p>This implementation returns the result of <tt>peek</tt> | ||
* unless the queue is empty. | ||
* | ||
* @return the head of this queue | ||
* @throws NoSuchElementException if this queue is empty | ||
*/ | ||
public E element() { | ||
E x = peek(); | ||
if (x != null) | ||
return x; | ||
else | ||
throw new NoSuchElementException(); | ||
} | ||
|
||
/** | ||
* Removes all of the elements from this queue. | ||
* The queue will be empty after this call returns. | ||
* | ||
* <p>This implementation repeatedly invokes {@link #poll poll} until it | ||
* returns <tt>null</tt>. | ||
*/ | ||
public void clear() { | ||
while (poll() != null) | ||
; | ||
} | ||
|
||
/** | ||
* Adds all of the elements in the specified collection to this | ||
* queue. Attempts to addAll of a queue to itself result in | ||
* <tt>IllegalArgumentException</tt>. Further, the behavior of | ||
* this operation is undefined if the specified collection is | ||
* modified while the operation is in progress. | ||
* | ||
* <p>This implementation iterates over the specified collection, | ||
* and adds each element returned by the iterator to this | ||
* queue, in turn. A runtime exception encountered while | ||
* trying to add an element (including, in particular, a | ||
* <tt>null</tt> element) may result in only some of the elements | ||
* having been successfully added when the associated exception is | ||
* thrown. | ||
* | ||
* @param c collection containing elements to be added to this queue | ||
* @return <tt>true</tt> if this queue changed as a result of the call | ||
* @throws ClassCastException if the class of an element of the specified | ||
* collection prevents it from being added to this queue | ||
* @throws NullPointerException if the specified collection contains a | ||
* null element and this queue does not permit null elements, | ||
* or if the specified collection is null | ||
* @throws IllegalArgumentException if some property of an element of the | ||
* specified collection prevents it from being added to this | ||
* queue, or if the specified collection is this queue | ||
* @throws IllegalStateException if not all the elements can be added at | ||
* this time due to insertion restrictions | ||
* @see #add(Object) | ||
*/ | ||
public boolean addAll(Collection<? extends E> c) { | ||
if (c == null) | ||
throw new NullPointerException(); | ||
if (c == this) | ||
throw new IllegalArgumentException(); | ||
boolean modified = false; | ||
for (E e : c) | ||
if (add(e)) | ||
modified = true; | ||
return modified; | ||
} | ||
|
||
} |
Oops, something went wrong.