1 /** 2 * Copyright 2003-2006 Greg Luck 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package net.sf.ehcache.hibernate; 17 18 import net.sf.ehcache.CacheManager; 19 import net.sf.ehcache.util.ClassLoaderUtil; 20 import org.apache.commons.logging.Log; 21 import org.apache.commons.logging.LogFactory; 22 import org.hibernate.cache.Cache; 23 import org.hibernate.cache.CacheException; 24 import org.hibernate.cache.CacheProvider; 25 import org.hibernate.cache.Timestamper; 26 27 import java.net.URL; 28 import java.util.Properties; 29 30 /** 31 * Cache Provider plugin for Hibernate 3.2 and ehcache-1.2. New in this provider are ehcache support for multiple 32 * Hibernate session factories, each with its own ehcache configuration, and non Serializable keys and values. 33 * Ehcache-1.2 also has many other features such as cluster support and listeners, which can be used seamlessly simply 34 * by configurion in ehcache.xml. 35 * <p/> 36 * Use <code>hibernate.cache.provider_class=org.hibernate.cache.EhCacheProvider</code> in the Hibernate configuration 37 * to enable ehcache as the second level cache. 38 * <p/> 39 * When configuring multiple ehcache CacheManagers, as you would where you have multiple Hibernate SessionFactories, 40 * specify in each Hibernate configuration the ehcache configuration using 41 * the property <code>net.sf.ehcache.configurationResourceName</code> An example to set an ehcach configuration 42 * called ehcache-2.xml would be <code>net.sf.ehcache.configurationResourceName=/ehcache-2.xml</code>. If the leading 43 * slash is not there one will be added. The configuration file will be looked for in the root of the classpath. 44 * <p/> 45 * Updated for ehcache-1.2. Note this provider requires ehcache-1.2.jar. Make sure ehcache-1.1.jar or earlier 46 * is not in the classpath or it will not work. 47 * <p/> 48 * See http://ehcache.sf.net for documentation on ehcache 49 * <p/> 50 * 51 * @author Greg Luck 52 * @author Emmanuel Bernard 53 * @version $Id: EhCacheProvider.java 52 2006-04-24 14:50:03Z gregluck $ 54 */ 55 public final class EhCacheProvider implements CacheProvider { 56 57 /** 58 * The Hibernate system property specifying the location of the ehcache configuration file name. 59 * <p/ 60 * If not set, ehcache.xml will be looked for in the root of the classpath. 61 * <p/> 62 * If set to say ehcache-1.xml, ehcache-1.xml will be looked for in the root of the classpath. 63 */ 64 public static final String NET_SF_EHCACHE_CONFIGURATION_RESOURCE_NAME = "net.sf.ehcache.configurationResourceName"; 65 66 private static final Log LOG = LogFactory.getLog(EhCacheProvider.class); 67 68 private CacheManager manager; 69 70 71 /** 72 * Builds a Cache. 73 * <p/> 74 * Even though this method provides properties, they are not used. 75 * Properties for EHCache are specified in the ehcache.xml file. 76 * Configuration will be read from ehcache.xml for a cache declaration 77 * where the name attribute matches the name parameter in this builder. 78 * 79 * @param name the name of the cache. Must match a cache configured in ehcache.xml 80 * @param properties not used 81 * @return a newly built cache will be built and initialised 82 * @throws org.hibernate.cache.CacheException 83 * inter alia, if a cache of the same name already exists 84 */ 85 public final Cache buildCache(String name, Properties properties) throws CacheException { 86 try { 87 net.sf.ehcache.Cache cache = manager.getCache(name); 88 if (cache == null) { 89 LOG.warn("Could not find a specific ehcache configuration for cache named [" + name + "]; using defaults."); 90 manager.addCache(name); 91 cache = manager.getCache(name); 92 EhCacheProvider.LOG.debug("started EHCache region: " + name); 93 } 94 return new net.sf.ehcache.hibernate.EhCache(cache); 95 } catch (net.sf.ehcache.CacheException e) { 96 throw new CacheException(e); 97 } 98 } 99 100 /** 101 * Returns the next timestamp. 102 */ 103 public final long nextTimestamp() { 104 return Timestamper.next(); 105 } 106 107 /** 108 * Callback to perform any necessary initialization of the underlying cache implementation 109 * during SessionFactory construction. 110 * <p/> 111 * 112 * @param properties current configuration settings. 113 */ 114 public final void start(Properties properties) throws CacheException { 115 try { 116 String configurationResourceName = null; 117 if (properties != null) { 118 configurationResourceName = (String) properties.get(NET_SF_EHCACHE_CONFIGURATION_RESOURCE_NAME); 119 } 120 if (configurationResourceName == null || configurationResourceName.length() == 0) { 121 manager = new CacheManager(); 122 } else { 123 if (!configurationResourceName.startsWith("/")) { 124 configurationResourceName = "/" + configurationResourceName; 125 if (LOG.isDebugEnabled()) { 126 LOG.debug("prepending / to " + configurationResourceName + ". It should be placed in the root" 127 + "of the classpath rather than in a package."); 128 } 129 } 130 URL url = loadResource(configurationResourceName); 131 manager = new CacheManager(url); 132 } 133 } catch (net.sf.ehcache.CacheException e) { 134 throw new CacheException(e); 135 } 136 } 137 138 private URL loadResource(String configurationResourceName) { 139 ClassLoader standardClassloader = ClassLoaderUtil.getStandardClassLoader(); 140 URL url = null; 141 if (standardClassloader != null) { 142 url = standardClassloader.getResource(configurationResourceName); 143 } 144 if (url == null) { 145 url = this.getClass().getResource(configurationResourceName); 146 } 147 if (LOG.isDebugEnabled()) { 148 LOG.debug("Creating EhCacheProvider from a specified resource: " 149 + configurationResourceName + " Resolved to URL: " + url); 150 } 151 return url; 152 } 153 154 /** 155 * Callback to perform any necessary cleanup of the underlying cache implementation 156 * during SessionFactory.close(). 157 */ 158 public final void stop() { 159 if (manager != null) { 160 manager.shutdown(); 161 manager = null; 162 } 163 } 164 165 /** 166 * Not sure what this is supposed to do. 167 * 168 * @return false to be safe 169 */ 170 public final boolean isMinimalPutsEnabledByDefault() { 171 return false; 172 } 173 174 } 175