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1 /*** 2 * Redistribution and use of this software and associated documentation 3 * ("Software"), with or without modification, are permitted provided 4 * that the following conditions are met: 5 * 6 * 1. Redistributions of source code must retain copyright 7 * statements and notices. Redistributions must also contain a 8 * copy of this document. 9 * 10 * 2. Redistributions in binary form must reproduce the 11 * above copyright notice, this list of conditions and the 12 * following disclaimer in the documentation and/or other 13 * materials provided with the distribution. 14 * 15 * 3. The name "Exolab" must not be used to endorse or promote 16 * products derived from this Software without prior written 17 * permission of Exoffice Technologies. For written permission, 18 * please contact info@exolab.org. 19 * 20 * 4. Products derived from this Software may not be called "Exolab" 21 * nor may "Exolab" appear in their names without prior written 22 * permission of Exoffice Technologies. Exolab is a registered 23 * trademark of Exoffice Technologies. 24 * 25 * 5. Due credit should be given to the Exolab Project 26 * (http://www.exolab.org/). 27 * 28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS 29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 39 * OF THE POSSIBILITY OF SUCH DAMAGE. 40 * 41 * Copyright 2000 (C) Exoffice Technologies Inc. All Rights Reserved. 42 * 43 * $Id: IdMessageComparator.java,v 1.4 2003/08/17 01:32:25 tanderson Exp $ 44 * 45 * Date Author Changes 46 * $Date jimm Created 47 */ 48 49 50 package org.exolab.jms.persistence; 51 52 import java.util.Comparator; 53 54 import javax.jms.JMSException; 55 56 57 /*** 58 * A comparator class that iplements a message id comparison for 59 * PersistentMessage. 60 * 61 * <P>Note this class assumes that id's are in some sort of order, such that 62 * an earlier generated id is less than a later generated id. 63 * 64 * @version $Revision: 1.4 $ $Date: 2003/08/17 01:32:25 $ 65 * @author <a href="mailto:mourikis@exolab.org">Jim Mourikis</a> 66 */ 67 public class IdMessageComparator implements Comparator { 68 69 /*** 70 * Default constructor does nothing. 71 * 72 */ 73 public IdMessageComparator() { 74 75 } 76 77 78 /*** 79 * Implements the compare operator. 80 * Compares its two arguments for order. Returns a negative integer, zero, 81 * or a positive integer as the first argument is less than, equal to, 82 * or greater than the second. 83 * 84 * @param Object object 1 to compare 85 * @param Object object 2 ro compare to. 86 * @return int returns -1, 0, 1 if the first argument is less than, 87 * equal to, or greater than the second. 88 * @exception ClassCastException if object types are unknown 89 * 90 */ 91 public int compare(Object o1, Object o2) 92 throws ClassCastException, NullPointerException { 93 int status; 94 95 if (o1 == null && o2 == null) 96 status = 0; 97 else if (o1 == null) 98 status = -1; 99 else if (o2 == null) 100 status = 1; 101 else if (o1 instanceof PersistentMessage && 102 o2 instanceof PersistentMessage) { 103 PersistentMessage m1 = (PersistentMessage) o1; 104 PersistentMessage m2 = (PersistentMessage) o2; 105 String t1; 106 String t2; 107 108 try { 109 t1 = m1.getMessage().getJMSMessageID(); 110 } catch (JMSException e1) { 111 t1 = ""; 112 } 113 try { 114 t2 = m2.getMessage().getJMSMessageID(); 115 } catch (JMSException e2) { 116 t2 = ""; 117 } 118 try { 119 status = t1.compareTo(t2); 120 } catch (NullPointerException err) { 121 // should never happen but! 122 System.err.println("Messages constain invalid id's"); 123 throw err; 124 } 125 } else { 126 throw new ClassCastException("Unknown Object"); 127 } 128 return status; 129 } 130 131 132 /*** 133 * Indicates whether some other object is "equal to" this Comparator. 134 * This method must obey the general contract of Object.equals(Object). 135 * 136 * @param Object the object to compare to 137 * @return boolean true iff objects are equal 138 * 139 */ 140 public boolean equals(Object ob) { 141 boolean status = false; 142 143 if (ob instanceof IdMessageComparator) status = true; 144 145 return status; 146 } 147 148 149 } // End IdMessageComparator

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