diff -r ee8a922f4268 -r d382dacfd73f rt/emul/compact/src/main/java/java/util/AbstractQueue.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/rt/emul/compact/src/main/java/java/util/AbstractQueue.java Tue Feb 26 16:54:16 2013 +0100 @@ -0,0 +1,192 @@ +/* + * 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. Oracle designates this + * particular file as subject to the "Classpath" exception as provided + * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* + * This file is available under and governed by the GNU General Public + * License version 2 only, as published by the Free Software Foundation. + * However, the following notice accompanied the original version of this + * file: + * + * Written by Doug Lea with assistance from members of JCP JSR-166 + * Expert Group and released to the public domain, as explained at + * http://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 not allow null + * 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 false or + * null returns. + * + *

A Queue implementation that extends this class must + * minimally define a method {@link Queue#offer} which does not permit + * insertion of null 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}. + * + *

This class is a member of the + * + * Java Collections Framework. + * + * @since 1.5 + * @author Doug Lea + * @param the type of elements held in this collection + */ +public abstract class AbstractQueue + extends AbstractCollection + implements Queue { + + /** + * 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 + * true upon success and throwing an IllegalStateException + * if no space is currently available. + * + *

This implementation returns true if offer succeeds, + * else throws an IllegalStateException. + * + * @param e the element to add + * @return true (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. + * + *

This implementation returns the result of poll + * 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. + * + *

This implementation returns the result of peek + * 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. + * + *

This implementation repeatedly invokes {@link #poll poll} until it + * returns null. + */ + 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 + * IllegalArgumentException. Further, the behavior of + * this operation is undefined if the specified collection is + * modified while the operation is in progress. + * + *

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 + * null 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 true 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 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; + } + +}