Redis实现分布式锁
/*** @author http://blog.iyunv.com/java2000_wl
* @version 1.0.0
*/
public class RedisBillLockHandler implements IBatchBillLockHandler {
private static final Logger LOGGER = LoggerFactory.getLogger(RedisBillLockHandler.class);
private static final int DEFAULT_SINGLE_EXPIRE_TIME = 3;
private static final int DEFAULT_BATCH_EXPIRE_TIME = 6;
private final JedisPool jedisPool;
/**
* 构造
* @author http://blog.iyunv.com/java2000_wl
*/
public RedisBillLockHandler(JedisPool jedisPool) {
this.jedisPool = jedisPool;
}
/**
* 获取锁如果锁可用 立即返回true，否则返回false
* @author http://blog.iyunv.com/java2000_wl
* @see com.fx.platform.components.lock.IBillLockHandler#tryLock(com.fx.platform.components.lock.IBillIdentify)
* @param billIdentify
* @return
*/
public boolean tryLock(IBillIdentify billIdentify) {
return tryLock(billIdentify, 0L, null);
}
/**
* 锁在给定的等待时间内空闲，则获取锁成功 返回true， 否则返回false
* @author http://blog.iyunv.com/java2000_wl
* @see com.fx.platform.components.lock.IBillLockHandler#tryLock(com.fx.platform.components.lock.IBillIdentify,
* long, java.util.concurrent.TimeUnit)
* @param billIdentify
* @param timeout
* @param unit
* @return
*/
public boolean tryLock(IBillIdentify billIdentify, long timeout, TimeUnit unit) {
String key = (String) billIdentify.uniqueIdentify();
Jedis jedis = null;
try {
jedis = getResource();
long nano = System.nanoTime();
do {
LOGGER.debug("try lock key: " + key);
Long i = jedis.setnx(key, key);
if (i == 1) {
jedis.expire(key, DEFAULT_SINGLE_EXPIRE_TIME);
LOGGER.debug("get lock, key: " + key + " , expire in " + DEFAULT_SINGLE_EXPIRE_TIME + " seconds.");
return Boolean.TRUE;
} else { // 存在锁
if (LOGGER.isDebugEnabled()) {
String desc = jedis.get(key);
LOGGER.debug("key: " + key + " locked by another business：" + desc);
}
}
if (timeout == 0) {
break;
}
Thread.sleep(300);
} while ((System.nanoTime() - nano) < unit.toNanos(timeout));
return Boolean.FALSE;
} catch (JedisConnectionException je) {
LOGGER.error(je.getMessage(), je);
returnBrokenResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
} finally {
returnResource(jedis);
}
return Boolean.FALSE;
}
/**
* 如果锁空闲立即返回 获取失败 一直等待
* @author http://blog.iyunv.com/java2000_wl
* @see com.fx.platform.components.lock.IBillLockHandler#lock(com.fx.platform.components.lock.IBillIdentify)
* @param billIdentify
*/
public void lock(IBillIdentify billIdentify) {
String key = (String) billIdentify.uniqueIdentify();
Jedis jedis = null;
try {
jedis = getResource();
do {
LOGGER.debug("lock key: " + key);
Long i = jedis.setnx(key, key);
if (i == 1) {
jedis.expire(key, DEFAULT_SINGLE_EXPIRE_TIME);
LOGGER.debug("get lock, key: " + key + " , expire in " + DEFAULT_SINGLE_EXPIRE_TIME + " seconds.");
return;
} else {
if (LOGGER.isDebugEnabled()) {
String desc = jedis.get(key);
LOGGER.debug("key: " + key + " locked by another business：" + desc);
}
}
Thread.sleep(300);
} while (true);
} catch (JedisConnectionException je) {
LOGGER.error(je.getMessage(), je);
returnBrokenResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
} finally {
returnResource(jedis);
}
}
/**
* 释放锁
* @author http://blog.iyunv.com/java2000_wl
* @see com.fx.platform.components.lock.IBillLockHandler#unLock(com.fx.platform.components.lock.IBillIdentify)
* @param billIdentify
*/
public void unLock(IBillIdentify billIdentify) {
List list = new ArrayList();
list.add(billIdentify);
unLock(list);
}
/**
* 批量获取锁如果全部获取 立即返回true, 部分获取失败 返回false
* @author http://blog.iyunv.com/java2000_wl
* @date 2013-7-22 下午10:27:44
* @see com.fx.platform.components.lock.IBatchBillLockHandler#tryLock(java.util.List)
* @param billIdentifyList
* @return
*/
public boolean tryLock(List billIdentifyList) {
return tryLock(billIdentifyList, 0L, null);
}
/**
* 锁在给定的等待时间内空闲，则获取锁成功 返回true， 否则返回false
* @author http://blog.iyunv.com/java2000_wl
* @param billIdentifyList
* @param timeout
* @param unit
* @return
*/
public boolean tryLock(List billIdentifyList, long timeout, TimeUnit unit) {
Jedis jedis = null;
try {
List needLocking = new CopyOnWriteArrayList();
List locked = new CopyOnWriteArrayList();
jedis = getResource();
long nano = System.nanoTime();
do {
// 构建pipeline，批量提交
Pipeline pipeline = jedis.pipelined();
for (IBillIdentify identify : billIdentifyList) {
String key = (String) identify.uniqueIdentify();
needLocking.add(key);
pipeline.setnx(key, key);
}
LOGGER.debug("try lock keys: " + needLocking);
// 提交redis执行计数
List results = pipeline.syncAndReturnAll();
for (int i = 0; i < results.size(); ++i) {
Long result = (Long) results.get(i);
String key = needLocking.get(i);
if (result == 1) { // setnx成功，获得锁
jedis.expire(key, DEFAULT_BATCH_EXPIRE_TIME);
locked.add(key);
}
}
needLocking.removeAll(locked); // 已锁定资源去除
if (CollectionUtils.isEmpty(needLocking)) {
return true;
} else {
// 部分资源未能锁住
LOGGER.debug("keys: " + needLocking + " locked by another business：");
}
if (timeout == 0) {
break;
}
Thread.sleep(500);
} while ((System.nanoTime() - nano) < unit.toNanos(timeout));
// 得不到锁，释放锁定的部分对象，并返回失败
if (!CollectionUtils.isEmpty(locked)) {
jedis.del(locked.toArray(new String));
}
return false;
} catch (JedisConnectionException je) {
LOGGER.error(je.getMessage(), je);
returnBrokenResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
} finally {
returnResource(jedis);
}
return true;
}
/**
* 批量释放锁
* @author http://blog.iyunv.com/java2000_wl
* @see com.fx.platform.components.lock.IBatchBillLockHandler#unLock(java.util.List)
* @param billIdentifyList
*/
public void unLock(List billIdentifyList) {
List keys = new CopyOnWriteArrayList();
for (IBillIdentify identify : billIdentifyList) {
String key = (String) identify.uniqueIdentify();
keys.add(key);
}
Jedis jedis = null;
try {
jedis = getResource();
jedis.del(keys.toArray(new String));
LOGGER.debug("release lock, keys :" + keys);
} catch (JedisConnectionException je) {
LOGGER.error(je.getMessage(), je);
returnBrokenResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
} finally {
returnResource(jedis);
}
}
/**
* @author http://blog.iyunv.com/java2000_wl
* @date 2013-7-22 下午9:33:45
* @return
*/
private Jedis getResource() {
return jedisPool.getResource();
}
/**
* 销毁连接
* @author http://blog.iyunv.com/java2000_wl
* @param jedis
*/
private void returnBrokenResource(Jedis jedis) {
if (jedis == null) {
return;
}
try {
//容错
jedisPool.returnBrokenResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
}
/**
* @author http://blog.iyunv.com/java2000_wl
* @param jedis
*/
private void returnResource(Jedis jedis) {
if (jedis == null) {
return;
}
try {
jedisPool.returnResource(jedis);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
}
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