[转]Ehcache 缓存应用

package com.datang.common.cache.flat;  
  
import java.net.URL;  
import java.util.List;  
  
import net.sf.ehcache.CacheManager;  
import net.sf.ehcache.Ehcache;  
import net.sf.ehcache.Element;  
  
import org.slf4j.Logger;  
import org.slf4j.LoggerFactory;  
  
import com.datang.common.tools.util.ResourceUtils;  
public abstract class FlatCache {  
    /** 
     * 日志 
     */  
    private static final Logger LOGGER = LoggerFactory  
            .getLogger(FlatCache.class);  
  
    /** 
     * 缓存配置文件 
     */  
    private static String CACHE_CONFIG_FILE = "config/flat_cache.xml";  
  
    /** 
     * Ehanche的缓存管理 
     */  
    private static CacheManager cacheManager = null;  
  
    /** 
     * 设置缓存配置文件，最开始设置才有效果，一旦缓存加载则不能改变 
     *  
     * @param cacheConfigFile 
     */  
    public static void setCacheConfigFile(String cacheConfigFile) {  
        CACHE_CONFIG_FILE = cacheConfigFile;  
    }  
  
    /** 
     * 按缺省配置创建缓存 
     *  
     * @param cacheName 
     */  
    public static void createCache(String cacheName) {  
        getCacheManager().addCache(cacheName);  
    }  
  
    /** 
     * 添加缓存 
     *  
     * @param cacheName 
     * @param key 
     * @param value 
     */  
    public static void put(String cacheName, String key, Object value) {  
        Ehcache cache = getCacheManager().getEhcache(cacheName);  
        cache.put(new Element(key, value));  
    }  
  
    /** 
     * 根据缓存名与key获取值 
     *  
     * @param cacheName 
     * @param key 
     * @return 
     */  
    public static Object get(String cacheName, String key) {  
        Ehcache cache = getCacheManager().getEhcache(cacheName);  
        Element e = cache.get(key);  
        return e == null ? null : e.getObjectValue();  
    }  
  
    /** 
     * 获取缓存名 
     *  
     * @return 
     */  
    public static String[] getCacheNames() {  
        return getCacheManager().getCacheNames();  
    }  
  
    /** 
     * 获取缓存的Keys 
     *  
     * @param cacheName 
     * @return 
     */  
    @SuppressWarnings("unchecked")  
    public static List<String> getKeys(String cacheName) {  
        Ehcache cache = getCacheManager().getEhcache(cacheName);  
        return (List<String>) cache.getKeys();  
    }  
  
    /** 
     * 清除所有 
     */  
    public static void clearAll() {  
        getCacheManager().clearAll();  
    }  
  
    /** 
     * 清空指定缓存 
     *  
     * @param cacheName 
     */  
    public static void clear(String cacheName) {  
        getCacheManager().getCache(cacheName).removeAll();  
    }  
  
    /** 
     * 删除指定对象 
     *  
     * @param cacheName 
     * @param key 
     * @return 
     */  
    public static boolean remove(String cacheName, String key) {  
        return getCacheManager().getCache(cacheName).remove(key);  
    }  
  
    /** 
     * 获取缓存大小 
     *  
     * @param cacheName 
     * @return 
     */  
    public static int getSize(String cacheName) {  
        return getCacheManager().getCache(cacheName).getSize();  
    }  
  
    /** 
     * 获取CacheManager 
     *  
     * @return 
     */  
    private static CacheManager getCacheManager() {  
        if (cacheManager != null) {  
            return cacheManager;  
        }  
  
        try {  
            URL url = ResourceUtils.getResource(CACHE_CONFIG_FILE);  
            cacheManager = CacheManager.create(url);  
        } catch (RuntimeException e) {  
            LOGGER.error("init flat cache failed", e);  
            throw e;  
        }  
  
        return cacheManager;  
    }  
}  

配置文件

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="ehcache.xsd"
         updateCheck="true" monitoring="autodetect"
         dynamicConfig="true">
   
    <defaultCache
           maxElementsInMemory="20"
           eternal="false"
           overflowToDisk="false"
           timeToIdleSeconds="1800"
           timeToLiveSeconds="1800">
    </defaultCache>
    
    <cache name="CDG-CACHE"
           maxElementsInMemory="20"
           overflowToDisk="false"
           eternal="false"
           timeToIdleSeconds="1800"
           timeToLiveSeconds="1800"
           memoryStoreEvictionPolicy="LRU"
           transactionalMode="off"
     />   
</ehcache>