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Java > Open Source Codes > org > apache > activemq > util > MessageComparatorSupport


1 /**
2  *
3  * Licensed to the Apache Software Foundation (ASF) under one or more
4  * contributor license agreements. See the NOTICE file distributed with
5  * this work for additional information regarding copyright ownership.
6  * The ASF licenses this file to You under the Apache License, Version 2.0
7  * (the "License"); you may not use this file except in compliance with
8  * the License. You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 package org.apache.activemq.util;
19
20 import javax.jms.Message JavaDoc;
21
22 import java.util.Comparator JavaDoc;
23
24 /**
25  * A base class for comparators which works on JMS {@link Message} objects
26  *
27  * @version $Revision: 426366 $
28  */
29 public abstract class MessageComparatorSupport implements Comparator JavaDoc {
30
31     public int compare(Object JavaDoc object1, Object JavaDoc object2) {
32         Message JavaDoc command1 = (Message JavaDoc) object1;
33         Message JavaDoc command2 = (Message JavaDoc) object2;
34         return compareMessages(command1, command2);
35     }
36
37     protected abstract int compareMessages(Message JavaDoc message1, Message JavaDoc message2);
38
39     protected int compareComparators(Comparable JavaDoc comparable, Comparable JavaDoc comparable2) {
40         if (comparable != null) {
41             return comparable.compareTo(comparable2);
42         }
43         else if (comparable2 != null) {
44             return comparable2.compareTo(comparable) * -1;
45         }
46         return 0;
47     }
48
49 }
50
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