| /******************************************************************************* |
| * Copyright (c) 2009 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.utility.internal; |
| |
| import java.io.Serializable; |
| import java.util.Collection; |
| import java.util.LinkedList; |
| |
| /** |
| * Straightforward implementation of the {@link Queue} interface. |
| */ |
| public class SimpleQueue<E> |
| implements Queue<E>, Cloneable, Serializable |
| { |
| private LinkedList<E> elements; |
| |
| private static final long serialVersionUID = 1L; |
| |
| |
| // ********** constructors ********** |
| |
| /** |
| * Construct an empty queue. |
| */ |
| public SimpleQueue() { |
| super(); |
| this.elements = new LinkedList<E>(); |
| } |
| |
| /** |
| * Construct a queue containing the elements of the specified |
| * collection. The queue will dequeue its elements in the same |
| * order they are returned by the collection's iterator (i.e. the |
| * first element returned by the collection's iterator will be the |
| * first element returned by {@link #dequeue()}). |
| */ |
| public SimpleQueue(Collection<? extends E> c) { |
| super(); |
| this.elements = new LinkedList<E>(c); |
| } |
| |
| |
| // ********** Queue implementation ********** |
| |
| public void enqueue(E o) { |
| this.elements.addLast(o); |
| } |
| |
| public E dequeue() { |
| return this.elements.removeFirst(); |
| } |
| |
| public E peek() { |
| return this.elements.getFirst(); |
| } |
| |
| public boolean isEmpty() { |
| return this.elements.isEmpty(); |
| } |
| |
| |
| // ********** Cloneable implementation ********** |
| |
| @Override |
| public SimpleQueue<E> clone() { |
| try { |
| @SuppressWarnings("unchecked") |
| SimpleQueue<E> clone = (SimpleQueue<E>) super.clone(); |
| @SuppressWarnings("unchecked") |
| LinkedList<E> ll = (LinkedList<E>) this.elements.clone(); |
| clone.elements = ll; |
| return clone; |
| } catch (CloneNotSupportedException ex) { |
| throw new InternalError(); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return StringTools.buildToStringFor(this, this.peek()); |
| } |
| |
| } |