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1 /*
2
3  ============================================================================
4                    The Apache Software License, Version 1.1
5  ============================================================================
6  
7  Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
8  
9  Redistribution and use in source and binary forms, with or without modifica-
10  tion, are permitted provided that the following conditions are met:
11  
12  1. Redistributions of source code must retain the above copyright notice,
13     this list of conditions and the following disclaimer.
14  
15  2. Redistributions in binary form must reproduce the above copyright notice,
16     this list of conditions and the following disclaimer in the documentation
17     and/or other materials provided with the distribution.
18  
19  3. The end-user documentation included with the redistribution, if any, must
20     include the following acknowledgment: "This product includes software
21     developed by the Apache Software Foundation (http://www.apache.org/)."
22     Alternately, this acknowledgment may appear in the software itself, if
23     and wherever such third-party acknowledgments normally appear.
24  
25  4. The names "Jakarta", "Avalon", "Excalibur" and "Apache Software Foundation"
26     must not be used to endorse or promote products derived from this software
27     without prior written permission. For written permission, please contact
28     apache@apache.org.
29  
30  5. Products derived from this software may not be called "Apache", nor may
31     "Apache" appear in their name, without prior written permission of the
32     Apache Software Foundation.
33  
34  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
35  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
36  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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38  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
39  DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
40  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
41  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
43  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44  
45  This software consists of voluntary contributions made by many individuals
46  on behalf of the Apache Software Foundation. For more information on the
47  Apache Software Foundation, please see <http://www.apache.org/>.
48  
49 */
50 package org.apache.avalon.excalibur.collections;
51
52 import java.util.NoSuchElementException JavaDoc;
53
54 /**
55  * A thread safe version of the PriorityQueue.
56  * Provides synchronized wrapper methods for all the methods
57  * defined in the PriorityQueue interface.
58  *
59  * @deprecated use org.apache.commons.collections.SynchronizedPriorityQueue instead
60  *
61  * @author <a HREF="mailto:ram.chidambaram@telus.com">Ram Chidambaram</a>
62  * @version CVS $Revision: 1.4 $ $Date: 2003/03/22 12:46:22 $
63  * @since 4.0
64  */
65 public final class SynchronizedPriorityQueue
66     implements PriorityQueue
67 {
68     private final PriorityQueue m_priorityQueue;
69
70     public SynchronizedPriorityQueue( final PriorityQueue priorityQueue )
71     {
72         m_priorityQueue = priorityQueue;
73     }
74
75     /**
76      * Clear all elements from queue.
77      */
78     public void clear()
79     {
80         synchronized( m_priorityQueue )
81         {
82             m_priorityQueue.clear();
83         }
84     }
85
86     /**
87      * Test if queue is empty.
88      *
89      * @return true if queue is empty else false.
90      */
91     public boolean isEmpty()
92     {
93         synchronized( m_priorityQueue )
94         {
95             return m_priorityQueue.isEmpty();
96         }
97     }
98
99     /**
100      * Insert an element into queue.
101      *
102      * @param element the element to be inserted
103      */
104     public void insert( final Object JavaDoc element )
105     {
106         synchronized( m_priorityQueue )
107         {
108             m_priorityQueue.insert( element );
109         }
110     }
111
112     /**
113      * Return element on top of heap but don't remove it.
114      *
115      * @return the element at top of heap
116      * @throws NoSuchElementException if isEmpty() == true
117      */
118     public Object JavaDoc peek() throws NoSuchElementException JavaDoc
119     {
120         synchronized( m_priorityQueue )
121         {
122             return m_priorityQueue.peek();
123         }
124     }
125
126     /**
127      * Return element on top of heap and remove it.
128      *
129      * @return the element at top of heap
130      * @throws NoSuchElementException if isEmpty() == true
131      */
132     public Object JavaDoc pop() throws NoSuchElementException JavaDoc
133     {
134         synchronized( m_priorityQueue )
135         {
136             return m_priorityQueue.pop();
137         }
138     }
139
140     public String JavaDoc toString()
141     {
142         synchronized( m_priorityQueue )
143         {
144             return m_priorityQueue.toString();
145         }
146     }
147 }
148
149
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