import java.util.List;
import java.util.UUID;import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.Transaction;
import redis.clients.jedis.exceptions.JedisException;/*** Jedis实现分布式锁**/
public class DistributionLock {private final JedisPool jedisPool;public DistributionLock(JedisPool jedisPool) {this.jedisPool = jedisPool;}/*** 获取分布式锁* * @param lockName*            竞争获取锁key* @param acquireTimeoutInMS*            获取锁超时时间* @param lockTimeoutInMS*            锁的超时时间* @return 获取锁标识*/public String acquireLockWithTimeout(String lockName,long acquireTimeoutInMS, long lockTimeoutInMS) {Jedis conn = null;boolean broken = false;String retIdentifier = null;try {conn = jedisPool.getResource();String identifier = UUID.randomUUID().toString();String lockKey = "lock:" + lockName;int lockExpire = (int) (lockTimeoutInMS / 1000);long end = System.currentTimeMillis() + acquireTimeoutInMS;while (System.currentTimeMillis() < end) {if (conn.setnx(lockKey, identifier) == 1) {conn.expire(lockKey, lockExpire);retIdentifier = identifier;}if (conn.ttl(lockKey) == -1) {conn.expire(lockKey, lockExpire);}try {Thread.sleep(10);} catch (InterruptedException ie) {Thread.currentThread().interrupt();}}} catch (JedisException je) {if (conn != null) {broken = true;jedisPool.returnBrokenResource(conn);}} finally {if (conn != null && !broken) {jedisPool.returnResource(conn);}}return retIdentifier;}/*** 释放锁* @param lockName 竞争获取锁key* @param identifier 释放锁标识* @return*/public boolean releaseLock(String lockName, String identifier) {Jedis conn = null;boolean broken = false;String lockKey = "lock:" + lockName;boolean retFlag = false;try {conn = jedisPool.getResource();while (true) {conn.watch(lockKey);if (identifier.equals(conn.get(lockKey))) {Transaction trans = conn.multi();trans.del(lockKey);List<Object> results = trans.exec();if (results == null) {continue;}retFlag = true;}conn.unwatch();break;}} catch (JedisException je) {if (conn != null) {broken = true;jedisPool.returnBrokenResource(conn);}} finally {if (conn != null && !broken) {jedisPool.returnResource(conn);}}return retFlag;}}