基于redis实现分布式锁

 1  public static boolean lock(String key){
 2        //获取redisTemplate
 3         RedisTemplate redisTemplate= RedisHelper.getTemplate();
 4         Boolean rs = (Boolean) redisTemplate.execute(new RedisCallback(key, 60*5));
 5         return  rs;
 6     }
 7 
 8     public static class RedisCallback implements org.springframework.data.redis.core.RedisCallback<Boolean> {
 9         private byte[] key;
10         private int expire;
11 
12         public RedisCallback(String key,int expire) {
13             this.expire = expire;
14             this.key = RedisHelper.getTemplate().getStringSerializer().serialize(key);
15         }
16 
17 
18         @Override
19         public Boolean doInRedis(RedisConnection redisConnection) throws DataAccessException {
20             //开启监听，一旦当前key发生变化，事务将被中断,将不会执行返回null
21             redisConnection.watch(key);
22             //若key存在，则获取不到锁
23             byte[] value= redisConnection.get(key);
24             if(value!=null){
25                 return false;
26             }
27             //事务块开始
28             redisConnection.multi();
29             redisConnection.setEx(key,expire,new byte[]{‘Y‘});
30             redisConnection.get(key);
31             //事务块执行，其返回值为执行事务块呢内所有命令的返回值，也就是上边为何加一条get(key),用于判断执行结果
32             List<Object> obj = redisConnection.exec();
33             if(CollectionUtils.isNotEmpty(obj)&&obj.size()==1){
34                 //成功则获取该锁
35                 return true;
36             }
37             return false;
38         }
39     }