Java 使用 memcached 的简单例子 缓存

MemCached 安装日志

关键字: memcached
1、下载memcached-1.2.1.tar.gz和libevent-1.3b.tar.gz；
2、安装libevent
tar xvfz  libevent-1.3b.tar.gz
cd libevent-1.3b
./configure && make
make install
3、安装memcache
tar xvfz  memcached-1.2.1.tar.gz
cd  memcached-1.2.1
./configure
make && make install
4、将libevent安装的/usr/local/lib输出到引用库路径
# vi ~/.bash_profile
加入如下一行：
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
5、启动(安装后位置：/usr/local/bin/memcached)
memcached  -d  -m 128 -l 192.168.0.50 -p 11211 -u root
即以root用户，分配最大2GM内存启动memcache
memcached  -d  -m 128 -l 192.168.0.50 -p 11212 -u root
在另外一个端口11212启动另外一个memcache实例

 

* Created on 2006-7-24
 * 连接缓存服务器
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class MemCacheWorkBench {
	
	private static final String POOL_NAME = "danqoo"; 
	
	private static final String CACHE_SERVER = "211.155.224.112:11211";

	private static MemCachedClient client = null;
	
	private static boolean USE_MEMCACHE_FLAG = true;

	public static MemCachedClient getMemCachedClient() {
		if (USE_MEMCACHE_FLAG){
			if (client == null) {
				String[] serverlist = { CACHE_SERVER };
				SockIOPool pool = SockIOPool.getInstance(POOL_NAME);
				pool.setServers(serverlist);
				// 设置初始连接数、最小和最大连接数以及最大处理时间
	
				pool.setInitConn( 5 );       
		        pool.setMinConn( 5 );       
		        pool.setMaxConn( 250 );       
		        pool.setMaxIdle( 1000 * 60 * 30);		        
		        // 设置主线程的睡眠时间
		        pool.setMaintSleep( 30 ); 	
				// 设置TCP的参数，连接超时等
		        pool.setNagle( false );       
		        //连接建立后对超时的控制    
		        pool.setSocketTO( 3000 );    
		        //连接建立时对超时的控制    
		        pool.setSocketConnectTO( 0 );   
				pool.initialize();   
				client = new MemCachedClient();
				// 压缩设置，超过指定大小（单位为K）的数据都会被压缩
				client.setCompressEnable(true);
				client.setCompressThreshold(4096);
				client.setPrimitiveAsString(true);
				client.setPoolName(POOL_NAME);
			}
			return client;
		}else{
			return null;
		}
	}
	
}

/*
 * Created on 2006-7-24
 * 单子模式实加载一个对象
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class MemCacheUtil {
	
	public static String indeKey = "danqoo.index";
	private static Integer OVER_TIME = 5*60*1000;
	private static Log logger = LogFactory.getLog(MemCacheUtil.class);
	private static MemCachedClient mc = MemCacheWorkBench.getMemCachedClient();

	
	public static Object get(String key) {
		if (mc != null && key != null && key.trim().length() > 0)
			return mc.get(key);
		else
			return null;
	}

	public static void set(String key, Object value) {
		if (mc != null && key != null && key.trim().length() > 0)
			mc.set(key, value,new Date(OVER_TIME));//过期时间设置默认
	}
	
	public static void set(String key, Object value,Date date) {
		if (mc != null && key != null && key.trim().length() > 0)
			mc.set(key, value,date);
	}

	public static void delete(String key) {
		if (mc != null && key != null && key.trim().length() > 0)
			mc.delete(key);
	}

	public static void clear() {
		if (mc != null){
			mc.flushAll();
		}	
	}
	
	public static String createKey(String id,Map map){
		StringBuffer sbuf = new StringBuffer();
		sbuf.append(id);
		for (Object key : map.keySet()) {			
			sbuf.append(".").append(key).append("=").append(map.get(key));
		}
		return  Utilities.encodePassword(sbuf.toString(), "md5");
	}
	
	public static String createKey(String id,String paraName,String value){
		StringBuffer sbuf = new StringBuffer();
		sbuf.append(id).append(".").append(paraName).append("=").append(value);
		return Utilities.encodePassword(sbuf.toString(), "md5");
	}
	
	public static String createKey(String id){		
		return Utilities.encodePassword(id.toString(), "md5");
	}
		
}

/** 
 * @Dao层运用缓存机制
 * @date:2008-9-17 
 * @time:上午09:42:03 
 */
public class AdvPicDaoImpl extends SqlMapClientDaoSupport implements IAdvPicDao{
	
	public AdvPicBean getAdvPic(int id) {
		
		return (AdvPicBean)this.getSqlMapClientTemplate().queryForObject("advpic.getAdvPic",id);
	}

	public void setAdvPic(AdvPicBean bean) {
		this.getSqlMapClientTemplate().insert("advpic.setAdvPic",bean);
		
	}		
	 public List<AdvPicBean> getAdvice(int begin,int advType,int advFileType)
	 {
		 Map map=new HashMap();
		 map.put("begin", begin);
		 map.put("adType", advType);
		 map.put("adFileType", advFileType);
		 String key = MemCacheUtil.createKey("advpic.getAdvice",map);
		 List<AdvPicBean> list = (List<AdvPicBean>) MemCacheUtil.get(key);
		 if (list == null ){
			 list =  this.getSqlMapClientTemplate().queryForList("advpic.getAdvice",map);
			 MemCacheUtil.set(key, list);
		 }
		 return list;
	 }


	public List<FLinkForm> findFLinkList(Integer num) {
//		return this.getSqlMapClientTemplate().queryForList("advpic.findFLinkList",num);
		String key = MemCacheUtil.createKey("advpic.findFLinkList","num",Integer.toBinaryString(num));
		Object obj = MemCacheUtil.get(key);
		if (obj !=null){
			return (List)obj;
		}else{
			List value = this.getSqlMapClientTemplate().queryForList("advpic.findFLinkList",num);
			MemCacheUtil.set(key, value);
			return value;
		}
	}

	public FLinkForm getAdvertiseCodeById(String id) {
		return (FLinkForm)this.getSqlMapClientTemplate().queryForObject("advpic.getAdvertiseCodeById", id);
	}

	public WordAdBean getWordAdByKey(String key) {
		return (WordAdBean)this.getSqlMapClientTemplate().queryForObject("advpic.getWordAdByKey", key);
	}			
}