利用Redisson实现分布式锁，并防止重复提交

关于Redisson的基础概念，参照Redisson基础。要想实现此功能需要以下几步：

1.依赖包

这里用的是jdk8+的版本<dependency><groupId>org.redisson</groupId><artifactId>redisson</artifactId><version>3.3.2</version></dependency>

2.Spring整合

注意设置schema文件<redisson:client id="redissonClient2"><redisson:single-server address="192.168.238.129:6379"/></redisson:client>

3.工具类

默认锁

@Component
public class DistributedRedisLock implements InitializingBean {
private static final Logger _log = Logger.getLogger(DistributedRedisLock.class);
@Autowired
private RedissonClient redissonClient;
public static Redisson redisson;

/**
* 获取默认锁
*/
public static RLock acquireLock(String lockName) {
RLock fairLock = redisson.getLock(lockName);
fairLock.lock();// 手动去解锁
_log.info("锁 - " + lockName + "获取成功"); return fairLock;
}

/**
* 释放默认锁
*/
public static void realeaseLock(RLock fairLock) {
fairLock.unlock();
}
@Override
public void afterPropertiesSet() throws Exception {
redisson = (Redisson) redissonClient;
_log.info(redisson.getConfig().toJSON());
}
}

如何防止重复呢？

/*** 存入分布式set对象中* @param name* @param value* @return*/public RSet<String> setSet(String name, String value){RSet<String> set = redisson.getSet(name);set.add(value);return  set;}/*** 检查分布式对象是否存在* @param name* @return*/public Boolean existSet(String name){RSet<String> set = redisson.getSet(name);if (!set.isEmpty()) {return  true;}return  false;}

调用代码：

	String lockname="lockname";RLock fairLock=DistributedRedisLock.acquireLock(lockname);try {//不存在设置到redisif (!DistributedRedisLock.existSet(lockname)) {DistributedRedisLock.setSet(lockname, "1111");//业务逻辑begin} else {//redis中有则不处理业务逻辑}}finally {DistributedRedisLock.realeaseLock(fairLock);}