001 package org.apache.fulcrum.cache; 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 */ 021 022 import java.io.Serializable; 023 024 /** 025 * Wrapper for an object you want to store in a cache for a period of time. 026 * 027 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a> 028 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 029 * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a> 030 * @version $Id: CachedObject.java 670326 2008-06-22 09:31:47Z tv $ 031 */ 032 033 public class CachedObject implements Serializable 034 { 035 /* 036 * TODO: The old Turbine version you could set the default age from Turbine. 037 * What we need is a CachedObjectFactory that would generate CachedObject's 038 * that could then have their default age set. 039 */ 040 041 /** 042 * Serialization key 043 */ 044 private static final long serialVersionUID = -9107764093769042092L; 045 046 /** Cache the object with the Default TTL */ 047 public static final int DEFAULT = 0; 048 049 /** Do not expire the object */ 050 public static final int FOREVER = -1; 051 052 /** The object to be cached. */ 053 private Object contents = null; 054 055 /** Default age (30 minutes). */ 056 private long defaultage = 1800000; 057 058 /** When created. * */ 059 protected long created = 0; 060 061 /** When it expires. * */ 062 private long expires = 0; 063 064 /** Is this object stale/expired? */ 065 private boolean stale = false; 066 067 /** 068 * Constructor; sets the object to expire in the default time (30 minutes). 069 * 070 * @param o 071 * The object you want to cache. 072 */ 073 public CachedObject(Object o) 074 { 075 this.contents = o; 076 this.expires = this.defaultage; 077 this.created = System.currentTimeMillis(); 078 } 079 080 /** 081 * Constructor. 082 * 083 * @param o 084 * The object to cache. 085 * @param expires 086 * How long before the object expires, in ms, e.g. 1000 = 1 087 * second. 088 */ 089 public CachedObject(Object o, long expires) 090 { 091 if (expires == DEFAULT) 092 { 093 this.expires = this.defaultage; 094 } 095 096 this.contents = o; 097 this.expires = expires; 098 this.created = System.currentTimeMillis(); 099 } 100 101 /** 102 * Returns the cached object. 103 * 104 * @return The cached object. 105 */ 106 public Object getContents() 107 { 108 return this.contents; 109 } 110 111 /** 112 * Returns the creation time for the object. 113 * 114 * @return When the object was created. 115 */ 116 public long getCreated() 117 { 118 return this.created; 119 } 120 121 /** 122 * Returns the expiration time for the object. 123 * 124 * @return When the object expires. 125 */ 126 public long getExpires() 127 { 128 return this.expires; 129 } 130 131 /** 132 * Set the expiration interval for the object. 133 * 134 * @param expires 135 * Expiration interval in millis ( 1 second = 1000 millis) 136 */ 137 public void setExpires(long expires) 138 { 139 if (expires == DEFAULT) 140 { 141 this.expires = this.defaultage; 142 } 143 else 144 { 145 this.expires = expires; 146 } 147 if (expires == FOREVER) 148 { 149 setStale(false); 150 } 151 else 152 { 153 setStale((System.currentTimeMillis() - this.created) > expires); 154 } 155 } 156 157 /** 158 * Set the stale status for the object. 159 * 160 * @param stale 161 * Whether the object is stale or not. 162 */ 163 public synchronized void setStale(boolean stale) 164 { 165 this.stale = stale; 166 } 167 168 /** 169 * Get the stale status for the object. 170 * 171 * @return Whether the object is stale or not. 172 */ 173 public synchronized boolean getStale() 174 { 175 return this.stale; 176 } 177 178 /** 179 * Is the object stale? 180 * 181 * @return True if the object is stale. 182 */ 183 public synchronized boolean isStale() 184 { 185 if (this.expires == FOREVER) 186 { 187 return false; 188 } 189 190 setStale((System.currentTimeMillis() - this.created) > this.expires); 191 return getStale(); 192 } 193 }