/**
* An abstract factory for creating CacheExtensions. Implementers should
* provide their own concrete factory extending this factory.
* It can then be configured in ehcache.xml.
*
*/
public abstract class CacheExtensionFactory {
/**
* @param cache the cache this extension should hold a reference to, and to
* whose lifecycle it should be bound.
* @param properties implementation specific properties configured as
* delimiter separated name value pairs in ehcache.xml
*/
public abstract CacheExtension createCacheExtension(Ehcache cache,
Properties properties);
}

/**
* This is a general purpose mechanism to allow generic extensions to a Cache.
*
* CacheExtensions are tied into the Cache lifecycle. For that reason this
* interface has the lifecycle methods.
*
* CacheExtensions are created using the CacheExtensionFactory which has a
* createCacheCacheExtension() method which takes as a parameter a Cache and
* properties. It can thus call back into any public method on Cache, including,
* of course, the load methods.
*
* CacheExtensions are suitable for timing services, where you want to create a
* timer to perform cache operations. The other way of adding Cache behaviour is
* to decorate a cache.
* See {@link net.sf.ehcache.constructs.blocking.BlockingCache}
* for an example of how to do this.
*
* Because a CacheExtension holds a reference to a Cache, the CacheExtension
* can do things such as registering a CacheEventListener or even a
* CacheManagerEventListener, all from within a CacheExtension,
* creating more opportunities for customisation.
*
*/
public interface CacheExtension {
/**
* Notifies providers to initialise themselves.
*
* This method is called during the Cache's initialise method after it
* has changed its status to alive. Cache operations are legal in
* this method.
*
* @throws CacheException
*/
void init();
/**
* Providers may be doing all sorts of exotic things and need to be able to
* clean up on dispose.
*
* Cache operations are illegal when this method is called. The cache
* itself is partly disposed when this method is called.
*
* @throws CacheException
*/
void dispose() throws CacheException;
/**
* Creates a clone of this extension. This method will only be called by
* Ehcache before a cache is initialized.
*
* Implementations should throw CloneNotSupportedException if they do not
* support clone but that will stop them from being used with defaultCache.
*
* @return a clone
* @throws CloneNotSupportedException if the extension could not be cloned.
*/
public CacheExtension clone(Ehcache cache) throws CloneNotSupportedException;
/**
* @return the status of the extension
*/
public Status getStatus();
}