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Redis实现分布式锁

/**  * @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;            /**      * 构造      * @author http://blog.csdn.net/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.csdn.net/java2000_wl      * @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.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);  //只有不存在的时候才设置                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.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);          }      }        /**      * 释放锁      * @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.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);      }            /**      * 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.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 {                  // 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<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,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[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;      }        /**      * 批量释放锁      * @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();      }            /**      * 销毁连接      * @author http://blog.csdn.net/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.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);          }      }  

  

Redis实现分布式锁