Redis實現分布式鎖__java

來源:互聯網
上載者:User

原文地址:http://blog.csdn.net/java2000_wl/article/details/8740911

參考地址:

http://www.cnblogs.com/dolphin0520/p/3923167.html

http://phl.iteye.com/blog/2029944


/** * @author http://blog.csdn.net/java2000_wl * @version <b>1.0.0</b> */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;/** * 構造 * @author http://blog.csdn.net/java2000_wl */public RedisBillLockHandler(JedisPool jedisPool) {this.jedisPool = jedisPool;}/** * 擷取鎖  如果鎖可用   立即返回true,  否則返回false * @author http://blog.csdn.net/java2000_wl * @param billIdentify * @return */public boolean tryLock(IBillIdentify billIdentify) {return tryLock(billIdentify, 0L, null);}/** * 鎖在給定的等待時間內空閑,則擷取鎖成功 返回true, 否則返回false * @author http://blog.csdn.net/java2000_wl * @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 { // 存在鎖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;}/** * 如果鎖空閑立即返回   擷取失敗 一直等待 * @author http://blog.csdn.net/java2000_wl * @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);}}/** * 釋放鎖 * @author http://blog.csdn.net/java2000_wl * @param billIdentify */public void unLock(IBillIdentify billIdentify) {List<IBillIdentify> list = new ArrayList<IBillIdentify>();list.add(billIdentify);unLock(list);}/** * 批量擷取鎖  如果全部擷取   立即返回true, 部分擷取失敗 返回false * @author http://blog.csdn.net/java2000_wl * @date 2013-7-22 下午10:27:44 * @param billIdentifyList * @return */public boolean tryLock(List<IBillIdentify> billIdentifyList) {return tryLock(billIdentifyList, 0L, null);}/** * 鎖在給定的等待時間內空閑,則擷取鎖成功 返回true, 否則返回false * @author http://blog.csdn.net/java2000_wl * @param billIdentifyList * @param timeout * @param unit * @return */public boolean tryLock(List<IBillIdentify> billIdentifyList, long timeout, TimeUnit unit) {Jedis jedis = null;try {List<String> needLocking = new CopyOnWriteArrayList<String>();List<String> locked = new CopyOnWriteArrayList<String>();jedis = getResource();long nano = System.nanoTime();do {// 構建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執行計數List<Object> 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,獲得鎖jedis.expire(key, DEFAULT_BATCH_EXPIRE_TIME);locked.add(key);} }needLocking.removeAll(locked);// 鎖定資源去除if (CollectionUtils.isEmpty(needLocking)) {return true;} else {// 部分資源未能鎖住LOGGER.debug("keys: " + needLocking + " locked by another business:");}if (timeout == 0) {break;}Thread.sleep(500);} while ((System.nanoTime() - nano) < unit.toNanos(timeout));// 得不到鎖,釋放鎖定的部分對象,並返回失敗if (!CollectionUtils.isEmpty(locked)) {jedis.del(locked.toArray(new String[0]));}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;}/** * 批量釋放鎖 * @author http://blog.csdn.net/java2000_wl * @param billIdentifyList */public void unLock(List<IBillIdentify> billIdentifyList) {List<String> keys = new CopyOnWriteArrayList<String>();for (IBillIdentify identify : billIdentifyList) {String key = (String) identify.uniqueIdentify();keys.add(key);}Jedis jedis = null;try {jedis = getResource();jedis.del(keys.toArray(new String[0]));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.csdn.net/java2000_wl * @date 2013-7-22 下午9:33:45 * @return */private Jedis getResource() {return jedisPool.getResource();}/** * 銷毀串連 * @author http://blog.csdn.net/java2000_wl * @param jedis */private void returnBrokenResource(Jedis jedis) {if (jedis == null) {return;}try {//容錯jedisPool.returnBrokenResource(jedis);} catch (Exception e) {LOGGER.error(e.getMessage(), e);}}/** * @author http://blog.csdn.net/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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