KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > mr > core > util > Queue


1 /*
2  * Copyright 2002 by
3  * <a HREF="http://www.coridan.com">Coridan</a>
4  * <a HREF="mailto: support@coridan.com ">support@coridan.com</a>
5  *
6  * The contents of this file are subject to the Mozilla Public License Version
7  * 1.1 (the "License"); you may not use this file except in compliance with the
8  * License. You may obtain a copy of the License at
9  * http://www.mozilla.org/MPL/
10  *
11  * Software distributed under the License is distributed on an "AS IS" basis,
12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13  * for the specific language governing rights and limitations under the
14  * License.
15  *
16  * The Original Code is "MantaRay" (TM).
17  *
18  * The Initial Developer of the Original Code is Amir Shevat.
19  * Portions created by the Initial Developer are Copyright (C) 2006
20  * Coridan Inc. All Rights Reserved.
21  *
22  * Contributor(s): all the names of the contributors are added in the source
23  * code where applicable.
24  *
25  * Alternatively, the contents of this file may be used under the terms of the
26  * LGPL license (the "GNU LESSER GENERAL PUBLIC LICENSE"), in which case the
27  * provisions of LGPL are applicable instead of those above. If you wish to
28  * allow use of your version of this file only under the terms of the LGPL
29  * License and not to allow others to use your version of this file under
30  * the MPL, indicate your decision by deleting the provisions above and
31  * replace them with the notice and other provisions required by the LGPL.
32  * If you do not delete the provisions above, a recipient may use your version
33  * of this file under either the MPL or the GNU LESSER GENERAL PUBLIC LICENSE.
34  
35  *
36  * This library is free software; you can redistribute it and/or modify it
37  * under the terms of the MPL as stated above or under the terms of the GNU
38  * Lesser General Public License as published by the Free Software Foundation;
39  * either version 2.1 of the License, or any later version.
40  *
41  * This library is distributed in the hope that it will be useful, but WITHOUT
42  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
43  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
44  * License for more details.
45  */
46 package org.mr.core.util;
47
48 /**
49  * A Queue is a FIFO (First In First Out) dispenser.
50  *
51  * @author Amir Shevat
52  * @version 1.0
53  */
54 public interface Queue {
55
56     /**
57      * Enqueue an element into the queue
58      *
59      * @param o The element to enqueue
60      * @return true if element enqueued else false
61      */
62     public boolean enqueue(Object JavaDoc o);
63     
64     /**
65      * De-queue an element from the queue
66      *
67      * @return The element
68      */
69     public Object JavaDoc dequeue();
70     
71     /**
72      * De-queue an element from the queue or null if there is no element
73      *
74      * @return The element
75      */
76     public Object JavaDoc dequeueNoBlock();
77
78     /**
79      * Is the queue empty?
80      *
81      * @return true iff the queue is empty
82      */
83     public boolean isEmpty();
84     
85     /**
86      * How many elements are currently enqueued?
87      *
88      * @return the number of elements in the queue
89      */
90      public int size();
91     
92 }
93
94
Popular Tags