+
+
+ * The purpose of this bean is to provide a common point from which the system-wide
+ * EHCache CacheManager singleton is created. Hibernate and Spring
+ * will all pick up the same CacheManager instance. It then becomes
+ * possible to initialise this instance in whichever way we require, provided it
+ * is done in a well-known (non-configurable) way.
+ *
+ * For Alfresco purposes, there are two files that are looked for:
+ *
+ * - classpath:alfresco/extension/ehcache-custom.xml, which will take precedence
+ * - classpath:alfresco/ehcache.xml, which is the default shipped with Alfresco
+ *
+ *
+ * The EHCache static singleton instance is used but ensuring that all access to the
+ * instance goes through the required initialization code first.
+ *
+ * TODO: Provide mixing of config so that cache definitions in the custom file override
+ * those in the default file
+ *
+ * @see #getInstance()
+ *
+ * @author Derek Hulley
+ */
+public class InternalEhCacheManagerFactoryBean implements FactoryBean, CacheProvider
+{
+ public static final String CUSTOM_CONFIGURATION_FILE = "classpath:alfresco/extension/ehcache-custom.xml";
+ public static final String DEFAULT_CONFIGURATION_FILE = "classpath:alfresco/ehcache-default.xml";
+
+ private static Log logger = LogFactory.getLog(InternalEhCacheManagerFactoryBean.class);
+
+ /** keep track of the singleton status to avoid work */
+ private static boolean initialized;
+ /** used to ensure that the existing Hibernate logic is maintained */
+ private static EhCacheProvider hibernateEhCacheProvider = new EhCacheProvider();
+
+ /**
+ * Default constructor required by Hibernate. In fact, we anticipate several
+ * instances of this class to be created.
+ */
+ public InternalEhCacheManagerFactoryBean()
+ {
+ }
+
+ /**
+ * News up the singleton cache manager according to the rules set out
+ * in the class comments.
+ */
+ private static synchronized void initCacheManager()
+ {
+ if (initialized)
+ {
+ return;
+ }
+ try
+ {
+ boolean defaultLocation = false;
+ try
+ {
+ URL configUrl = ResourceUtils.getURL(CUSTOM_CONFIGURATION_FILE);
+ CacheManager.create(configUrl);
+ }
+ catch (FileNotFoundException e)
+ {
+ // try the alfresco default
+ URL configUrl = ResourceUtils.getURL(DEFAULT_CONFIGURATION_FILE);
+ CacheManager.create(configUrl); // this file MUST be present
+ defaultLocation = true;
+ }
+ // done
+ if (logger.isDebugEnabled())
+ {
+ logger.debug("Created EHCache CacheManager instance: \n" +
+ " configuration: " + (defaultLocation ? DEFAULT_CONFIGURATION_FILE : CUSTOM_CONFIGURATION_FILE));
+ }
+ initialized = true;
+ }
+ catch (Throwable e)
+ {
+ throw new AlfrescoRuntimeException("EHCache configuration failed", e);
+ }
+ }
+
+ /**
+ * @return Returns the properly initialized instance for Alfresco internal use
+ *
+ * @see #initCacheManager()
+ */
+ public static CacheManager getInstance()
+ {
+ initCacheManager();
+ return CacheManager.getInstance();
+ }
+
+ /**
+ * @see #hibernateEhCacheProvider
+ */
+ public Cache buildCache(String regionName, Properties properties) throws CacheException
+ {
+ initCacheManager();
+ return hibernateEhCacheProvider.buildCache(regionName, properties);
+ }
+
+ /**
+ * @see #hibernateEhCacheProvider
+ */
+ public boolean isMinimalPutsEnabledByDefault()
+ {
+ return hibernateEhCacheProvider.isMinimalPutsEnabledByDefault();
+ }
+
+ /**
+ * @see #hibernateEhCacheProvider
+ */
+ public long nextTimestamp()
+ {
+ return hibernateEhCacheProvider.nextTimestamp();
+ }
+
+ /**
+ * @see #initCacheManager()
+ * @see #hibernateEhCacheProvider
+ */
+ public void start(Properties properties) throws CacheException
+ {
+ initCacheManager();
+ hibernateEhCacheProvider.start(properties);
+ }
+
+ /**
+ * @see #initCacheManager()
+ * @see #hibernateEhCacheProvider
+ */
+ public void stop()
+ {
+ initCacheManager();
+ hibernateEhCacheProvider.stop();
+ }
+
+ /**
+ * @return Returns the singleton cache manager
+ *
+ * @see #initCacheManager()
+ */
+ public Object getObject() throws Exception
+ {
+ initCacheManager();
+ return CacheManager.getInstance();
+ }
+
+ /**
+ * @return Returns the singleton cache manager type
+ */
+ public Class getObjectType()
+ {
+ return CacheManager.class;
+ }
+
+ /**
+ * @return Returns true always
+ */
+ public boolean isSingleton()
+ {
+ return true;
+ }
+}