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1 package org.apache.torque.om; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache Turbine" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * "Apache Turbine", nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>. 55 */ 56 57 import java.io.Serializable; 58 import org.apache.torque.TorqueException; 59 60 /*** 61 * This class can be used to uniquely identify an object within 62 * an application. There are four subclasses: StringKey, NumberKey, 63 * and DateKey, and ComboKey which is a Key made up of a combination 64 * ofthe first three. 65 * 66 * @author <a href="mailto:jmcnally@apache.org">John McNally</a> 67 * @version $Id: ObjectKey.java,v 1.6 2002/11/26 22:32:55 mpoeschl Exp $ 68 */ 69 public abstract class ObjectKey implements Serializable, Comparable 70 { 71 /*** 72 * The underlying key value. 73 */ 74 protected Object key; 75 76 /*** 77 * Initializes the internal key value to <code>null</code>. 78 */ 79 protected ObjectKey() 80 { 81 key = null; 82 } 83 84 /*** 85 * Returns the hashcode of the underlying value (key), if key is 86 * not null. Otherwise calls Object.hashCode() 87 * 88 * @return an <code>int</code> value 89 */ 90 public int hashCode() 91 { 92 if (key == null) 93 { 94 return super.hashCode(); 95 } 96 return key.hashCode(); 97 } 98 99 /*** 100 * Get the underlying object. 101 * 102 * @return the underlying object 103 */ 104 public Object getValue() 105 { 106 return key; 107 } 108 109 /*** 110 * Appends a String representation of the key to a buffer. 111 * 112 * @param sb a <code>StringBuffer</code> 113 */ 114 public void appendTo(StringBuffer sb) 115 { 116 sb.append(this.toString()); 117 } 118 119 /*** 120 * Implements the compareTo method. 121 * 122 * @param obj the object to compare to this object 123 * @return a numeric comparison of the two values 124 */ 125 public int compareTo(Object obj) 126 { 127 return toString().compareTo(obj.toString()); 128 } 129 130 /*** 131 * Reset the underlying object using a String. 132 * 133 * @param s a <code>String</code> value 134 * @exception TorqueException if an error occurs 135 */ 136 public abstract void setValue(String s) throws TorqueException; 137 }

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