EhCacheProvider.java

//$Id: EhCacheProvider.java 9964 2006-05-30 15:40:54Z epbernard $
package com.ketayao.fensy.cache;

import java.util.Hashtable;

import net.sf.ehcache.CacheManager;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.ketayao.fensy.exception.CacheException;

/**
 * Cache Provider plugin
 * 
 * Taken from EhCache 1.3 distribution
 */
public class EhCacheProvider implements CacheProvider {

    private static final Logger log = LoggerFactory.getLogger(EhCacheProvider.class);

	private CacheManager manager;
	private Hashtable<String, EhCache> _cacheManager ;

    /**
     * Builds a Cache.
     * <p>
     * Even though this method provides properties, they are not used.
     * Properties for EHCache are specified in the ehcache.xml file.
     * Configuration will be read from ehcache.xml for a cache declaration
     * where the name attribute matches the name parameter in this builder.
     *
     * @param name the name of the cache. Must match a cache configured in ehcache.xml
     * @param properties not used
     * @return a newly built cache will be built and initialised
     * @throws CacheException inter alia, if a cache of the same name already exists
     */
    public EhCache buildCache(String name, boolean autoCreate) throws CacheException {
    	EhCache ehcache = _cacheManager.get(name);
    	if(ehcache == null && autoCreate){
		    try {
	            net.sf.ehcache.Cache cache = manager.getCache(name);
	            if (cache == null) {
	                log.warn("Could not find configuration [" + name + "]; using defaults.");
	                manager.addCache(name);
	                cache = manager.getCache(name);
	                log.debug("started EHCache region: " + name);                
	            }
	            synchronized(_cacheManager){
		            ehcache = new EhCache(cache);
		            _cacheManager.put(name, ehcache);
		            return ehcache ;
	            }
		    }
	        catch (net.sf.ehcache.CacheException e) {
	            throw new CacheException(e);
	        }
    	}
        return ehcache;
    }

	/**
	 * Callback to perform any necessary initialization of the underlying cache implementation
	 * during SessionFactory construction.
	 *
	 * @param properties current configuration settings.
	 */
	public void start() throws CacheException {
		if (manager != null) {
            log.warn("Attempt to restart an already started EhCacheProvider. Use sessionFactory.close() " +
                    " between repeated calls to buildSessionFactory. Using previously created EhCacheProvider." +
                    " If this behaviour is required, consider using net.sf.ehcache.hibernate.SingletonEhCacheProvider.");
            return;
        }
        manager = new CacheManager();
        _cacheManager = new Hashtable<String, EhCache>();
	}

	/**
	 * Callback to perform any necessary cleanup of the underlying cache implementation
	 * during SessionFactory.close().
	 */
	public void stop() {
		if (manager != null) {
            manager.shutdown();
            manager = null;
        }
	}

}