* 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: *
* 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;
/** the CacheManager */
private static CacheManager cacheManager;
/** 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);
InternalEhCacheManagerFactoryBean.cacheManager = new CacheManager(configUrl);
}
catch (FileNotFoundException e)
{
// try the alfresco default
URL configUrl = ResourceUtils.getURL(DEFAULT_CONFIGURATION_FILE);
if (configUrl == null)
{
throw new AlfrescoRuntimeException("Missing default cache config: " + DEFAULT_CONFIGURATION_FILE);
}
InternalEhCacheManagerFactoryBean.cacheManager = new CacheManager(configUrl);
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()
{
if (!InternalEhCacheManagerFactoryBean.initialized)
{
InternalEhCacheManagerFactoryBean.initCacheManager();
}
return InternalEhCacheManagerFactoryBean.cacheManager;
}
public Cache buildCache(String regionName, Properties properties) throws CacheException
{
CacheManager manager = InternalEhCacheManagerFactoryBean.getInstance();
try
{
net.sf.ehcache.Cache cache = manager.getCache(regionName);
if (cache == null)
{
logger.info("Using default cache configuration: " + regionName);
manager.addCache(regionName);
cache = manager.getCache(regionName);
logger.debug("Started EHCache region: " + regionName);
}
return new EhCache(cache);
}
catch (net.sf.ehcache.CacheException e)
{
throw new CacheException(e);
}
}
/**
* @see #hibernateEhCacheProvider
*/
public boolean isMinimalPutsEnabledByDefault()
{
return false;
}
/**
* @see #hibernateEhCacheProvider
*/
public long nextTimestamp()
{
return Timestamper.next();
}
/**
* @see #initCacheManager()
*/
public void start(Properties properties) throws CacheException
{
InternalEhCacheManagerFactoryBean.initCacheManager();
}
/**
* @see #initCacheManager()
*/
public void stop()
{
synchronized (getClass())
{
InternalEhCacheManagerFactoryBean.getInstance().shutdown();
initialized = false;
}
}
/**
* @return Returns the singleton cache manager
*
* @see #initCacheManager()
*/
public Object getObject() throws Exception
{
return InternalEhCacheManagerFactoryBean.getInstance();
}
/**
* @return Returns the singleton cache manager type
*/
public Class getObjectType()
{
return CacheManager.class;
}
/**
* @return Returns true always
*/
public boolean isSingleton()
{
return true;
}
}