ehcache 使用方法

引用 ：http://blog.csdn.net/zk_zhangkai/article/details/6921924

[java] view plaincopy

一种ehcache实现缓存的方式

/**
 *
 */
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;

/**
 * 平面缓存，按缓存名区分缓存，key-value结构
 *

 */
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;
    }
}

xml的配置如下：

<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>