import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Properties;
import java.util.Set;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;import org.apache.commons.codec.digest.DigestUtils;
import org.apache.ibatis.cache.Cache;
import org.apache.log4j.Logger;import redis.clients.jedis.Jedis;/** 使用第三方缓存服务器，处理二级缓存* zuimao*/
public class RedisCache implements Cache {private static final Logger logger = Logger.getLogger(RedisCache.class);/** The ReadWriteLock. */private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();private final String COMMON_CACHE_KEY = "MYBATIS:";private static final String UTF_8 = "utf-8";/*** 按照一定规则标识key*/private String getKey(Object key) {StringBuilder accum = new StringBuilder();accum.append(COMMON_CACHE_KEY);accum.append(this.id).append(":");accum.append(DigestUtils.md5Hex(String.valueOf(key)));return accum.toString();}/*** redis key规则前缀*/private String getKeys() {return COMMON_CACHE_KEY + this.id + ":*";}private String id; public RedisCache() {}public RedisCache(final String id) {if (id == null) {throw new IllegalArgumentException("必须传入ID");}logger.debug("MybatisRedisCache:id=" + id);this.id = id;}@Overridepublic String getId() {return this.id;}@Overridepublic int getSize() {Jedis jedis = null;int result = 0;try {jedis = RedisStandAloneUtil.getJedisPool().getResource();Set<byte[]> keys = jedis.keys(getKeys().getBytes(UTF_8));if (null != keys && !keys.isEmpty()) {result = keys.size();}logger.debug(this.id+"---->>>>总缓存数:" + result);} catch (Exception e) {logger.error(e.getMessage(), e);} finally {if (jedis != null) {jedis.close();}}return result;}@Overridepublic void putObject(Object key, Object value) {Jedis jedis = null;try {jedis = RedisStandAloneUtil.getJedisPool().getResource();             byte[] keys = getKey(key).getBytes(UTF_8);jedis.set(keys, SerializeUtil.serialize(value));logger.debug("添加缓存--------"+this.id);//getSize();} catch (Exception e) {logger.error(e.getMessage(), e);} finally {if (jedis != null) {jedis.close();}}}@Overridepublic Object getObject(Object key) {Jedis jedis = null;Object value = null;try {jedis = RedisStandAloneUtil.getJedisPool().getResource();value = SerializeUtil.unserialize(jedis.get(getKey(key).getBytes(UTF_8)));logger.debug("从缓存中获取-----"+this.id);//getSize();} catch (Exception e) {logger.error(e.getMessage(), e);} finally {if (jedis != null) {jedis.close();}}return value;}@Overridepublic Object removeObject(Object key) {Jedis jedis = null;Object value = null;try {jedis = RedisStandAloneUtil.getJedisPool().getResource();value = jedis.del(getKey(key).getBytes(UTF_8));logger.debug("LRU算法从缓存中移除-----"+this.id);//getSize();} catch (Exception e) {logger.error(e.getMessage(), e);} finally {if (jedis != null) {jedis.close();}}return value;}@Overridepublic void clear() {Jedis jedis = null;try {jedis = RedisStandAloneUtil.getJedisPool().getResource();Set<byte[]> keys = jedis.keys(getKeys().getBytes(UTF_8));logger.debug("出现CUD操作，清空对应Mapper缓存======>"+keys.size());for (byte[] key : keys) {jedis.del(key);}//下面是网上流传的方法，极大的降低系统性能，没起到加入缓存应有的作用，这是不可取的。//jedis.flushDB();//jedis.flushAll();} catch (Exception e) {logger.error(e.getMessage(), e);} finally {if (jedis != null) {jedis.close();}}}@Overridepublic ReadWriteLock getReadWriteLock() {return readWriteLock;}}