java-classic-code/java-commons-cache/impl/Ehcache.java

/** Copyright 2009 by primeton Corporation.
 *   
 * All rights reserved.
 *
 * This software is the confidential and proprietary information of
 * primeton Corporation ('Confidential Information').  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with primeton.
 */
package com.primeton.dgs.kernel.core.cache.impl;

import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;

import com.primeton.dgs.kernel.core.cache.ICache;
import net.sf.ehcache.search.Attribute;
import net.sf.ehcache.search.Query;
import net.sf.ehcache.search.Result;
import net.sf.ehcache.search.Results;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.net.URL;
import java.util.List;

/**
 * @author xiongbin
 * @Version 2012-9-4
 */
public class Ehcache implements ICache<Object> {


	private static Logger logger = LoggerFactory.getLogger(Ehcache.class);


	/**
	 * EHCache
	 */
	private final net.sf.ehcache.Ehcache cache;
	
	public Ehcache(){
        URL resource = Ehcache.class.getResource("/ehcache.xml");
        CacheManager manager = CacheManager.create(resource);
		net.sf.ehcache.Ehcache ehcache = manager.getCache("Cache");
		if(ehcache==null){
			manager.addCache("Cache");
			ehcache = manager.getEhcache("Cache");
		}
		this.cache = ehcache;
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#add(java.lang.String, java.lang.Object)
	 */
	@Override
	public void add(String key, Object value) {
		Element element = new Element(key, value);
		cache.put(element);
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#add(java.lang.String, java.lang.Integer, java.lang.Object)
	 */
	@Override
	public void add(String key, int exp, Object value) {
		Element element = new Element(key, value);
		element.setTimeToLive(exp);
		cache.put(element);
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#replace(java.lang.String, java.lang.Object)
	 */
	@Override
	public void replace(String key, Object value) {
		cache.put(new Element(key, value));
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#replace(java.lang.String, java.lang.Integer, java.lang.Object)
	 */
	@Override
	public void replace(String key, int exp, Object value) {
		add(key, exp, value);
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#get(java.lang.String)
	 */
	@Override
	public Object get(String key) {
		Element element = cache.get(key);
		if(element != null){
			return element.getValue();
		}
		return null;
	}


	/**
	 * 移除某条缓存
	 * @param key 缓存的 KEY
	 * @return
	 */
	@Override
	public Object remove(String key) {
		Element element = cache.get(key);
		cache.remove(key);
		logger.info("remove cache key: {}", key);
		if(element != null){
			return element.getObjectValue();
		}
		return null;
	}


	@Override
	public int removeByPrefix(String prefix) {
        Attribute<Object> keySearch = cache.getSearchAttribute("key");
		//创建一个用于查询的Query对象
		Query query = cache.createQuery();
		//给当前query添加一个筛选条件——可查询属性name的值等于“name1”
		query.addCriteria(keySearch.ilike(prefix+"*"));

		// ehcache 模糊删除
		query.includeAttribute(keySearch);
		query.includeKeys();
		Results result = query.execute();
		List<Result> keys = result.all();
		for (Result key : keys) {
			remove((String)key.getKey());
		}
		return result.size();
	}

	/* (non-Javadoc)
	 * @see com.primeton.dgs.kernel.common.cache.ICache#clear()
	 */
	@Override
	public void clear() {
		cache.removeAll();
	}

    /**
     * 获得缓存队列的长度
     * @return 返回大于等于 0 则代表真实长度，返回 -1 代表无法获得
     */
    @Override public int size() {
        return cache.getSize();
    }


	@Override
	public void close() throws IOException {
		cache.flush();
	}
}