001package org.apache.commons.jcs.engine; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import org.apache.commons.jcs.engine.behavior.ICacheElement; 023import org.apache.commons.jcs.engine.behavior.IElementAttributes; 024 025/** 026 * Generic element wrapper. Often stuffed inside another. 027 */ 028public class CacheElement<K, V> 029 implements ICacheElement<K, V> 030{ 031 /** Don't change */ 032 private static final long serialVersionUID = -6062305728297627263L; 033 034 /** The name of the cache region. This is a namespace. */ 035 private final String cacheName; 036 037 /** This is the cache key by which the value can be referenced. */ 038 private final K key; 039 040 /** This is the cached value, reference by the key. */ 041 private final V val; 042 043 /** 044 * These attributes hold information about the element and what it is 045 * allowed to do. 046 */ 047 private IElementAttributes attr; 048 049 /** 050 * Constructor for the CacheElement object 051 * <p> 052 * @param cacheName 053 * @param key 054 * @param val 055 */ 056 public CacheElement( String cacheName, K key, V val ) 057 { 058 this.cacheName = cacheName; 059 this.key = key; 060 this.val = val; 061 } 062 063 /** 064 * Constructor for the CacheElement object 065 * <p> 066 * @param cacheName 067 * @param key 068 * @param val 069 * @param attrArg 070 */ 071 public CacheElement( String cacheName, K key, V val, IElementAttributes attrArg ) 072 { 073 this(cacheName, key, val); 074 this.attr = attrArg; 075 } 076 077 /** 078 * Gets the cacheName attribute of the CacheElement object 079 * <p> 080 * @return The cacheName value 081 */ 082 @Override 083 public String getCacheName() 084 { 085 return this.cacheName; 086 } 087 088 /** 089 * Gets the key attribute of the CacheElement object 090 * <p> 091 * @return The key value 092 */ 093 @Override 094 public K getKey() 095 { 096 return this.key; 097 } 098 099 /** 100 * Gets the val attribute of the CacheElement object 101 * <p> 102 * @return The val value 103 */ 104 @Override 105 public V getVal() 106 { 107 return this.val; 108 } 109 110 /** 111 * Sets the attributes attribute of the CacheElement object 112 * <p> 113 * @param attr 114 * The new IElementAttributes value 115 */ 116 @Override 117 public void setElementAttributes( IElementAttributes attr ) 118 { 119 this.attr = attr; 120 } 121 122 /** 123 * Gets the IElementAttributes attribute of the CacheElement object 124 * <p> 125 * @return The IElementAttributes value, never null 126 */ 127 @Override 128 public IElementAttributes getElementAttributes() 129 { 130 // create default attributes if they are null 131 // this shouldn't happen, but could if a corrupt 132 // object was sent over the wire. 133 if ( this.attr == null ) 134 { 135 this.attr = new ElementAttributes(); 136 } 137 return this.attr; 138 } 139 140 /** 141 * @return a hash of the key only 142 */ 143 @Override 144 public int hashCode() 145 { 146 return key.hashCode(); 147 } 148 149 /** 150 * For debugging only. 151 * <p> 152 * @return String representation 153 */ 154 @Override 155 public String toString() 156 { 157 return "[CacheElement: cacheName [" + cacheName + "], key [" + key + "], val [" + val + "], attr [" + attr 158 + "]"; 159 } 160}