redis实现分布式锁
public class RedisDistriLock {
private final JedisPool jedisPool;
public RedisDistriLock(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) {
je.printStackTrace();
if (conn != null) {
broken = true;
conn.close();
}
} finally {
if (conn != null && !broken) {
conn.close();
}
}
return retFlag;
}
public static void main(String[] args) {
JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
jedisPoolConfig.setMaxTotal(20);
jedisPoolConfig.setMaxIdle(10);
JedisPool jedisPool = new JedisPool(jedisPoolConfig, "192.168.72.128", 6379);
RedisDistriLock lock = new RedisDistriLock(jedisPool);
String result = lock.acquireLockWithTimeout("aaa",11111,13331);
System.out.println("lock:" + result);
System.out.println(lock.releaseLock("aaa",result));
}
}Java代码GitHub地址: 地址