redissonClient 分布式锁的使用
在集群的情况下,用户多次请求接口时,存入的内容可能会导致重复,这时候就可以使用分布式锁来限制适用场景 分布式应用,分布式缓存,分布式回话管理,分布式服务(任务,延迟任务,执行器),分布式redis客户端第一步:导入依赖<!-- redis 分布式锁框架 --><dependency><groupId>org.redisson</groupId>&l
在集群的情况下,用户多次请求接口时,存入的内容可能会导致重复,这时候就可以使用分布式锁来限制
适用场景
分布式应用,分布式缓存,分布式回话管理,分布式服务(任务,延迟任务,执行器),分布式redis客户端
第一步:导入依赖
<!-- redis 分布式锁框架 -->
<dependency>
<groupId>org.redisson</groupId>
<artifactId>redisson</artifactId>
<version>3.12.5</version>
</dependency>
第二步:配置连接redis
程序化配置方法
Config config = new Config();
//存放在哪个服务器的redisIP地址加redis端口号
config. useSingleServer().setAddress("127.0.0.1:6379");
RedissonClient redisson = Redisson.create(config);
验证是否连接成功
redisson.getConfig().toJSON().toString()
结果 {"singleServerConfig":{"idleConnectionTimeout":10000,"pingTimeout":1000,"connectTimeout":10000,"timeout":3000,"retryAttempts":3,"retryInterval":1500,"reconnectionTimeout":3000,"failedAttempts":3,"subscriptionsPerConnection":5,"address":"redis://127.0.0.1:6379","subscriptionConnectionMinimumIdleSize":1,"subscriptionConnectionPoolSize":50,"connectionMinimumIdleSize":10,"connectionPoolSize":64,"database":0,"dnsMonitoring":false,"dnsMonitoringInterval":5000},"threads":0,"nettyThreads":0,"codec":{"class":"org.redisson.codec.JsonJacksonCodec"},"codecProvider":{"class":"org.redisson.codec.DefaultCodecProvider"},"resolverProvider":{"class":"org.redisson.liveobject.provider.DefaultResolverProvider"},"redissonReferenceEnabled":true,"useLinuxNativeEpoll":false}
测试写法
public class LockExamples {
public static void main(String[] args) throws InterruptedException {
// 默认连接上127.0.0.1:6379
RedissonClient client = Redisson.create();
// RLock 继承了 java.util.concurrent.locks.Lock 接口
RLock lock = client.getLock("lock");
lock.lock();
System.out.println("lock acquired");
Thread t = new Thread(() -> {
//获取锁,传入要锁的key
RLock lock1 = client.getLock("lock");
//获取锁
lock1.lock();
System.out.println("lock acquired by thread");
//解锁
lock1.unlock();
System.out.println("lock released by thread");
});
t.start();
t.join(1000);
lock.unlock();
System.out.println("lock released");
t.join();
client.shutdown();
}
}
飞花令的写法
@Override
@Transactional(rollbackFor = Exception.class)
public FlyingFlowerV1Vo insert(FlyingFlowerReq flyingFlowerReq, String userId) throws Exception {
//对进来的用户加锁
RLock userLock = redissonClient.getLock(RedissonKey.USER_ID + userId);
try{
//尝试加锁, 最多等待1秒, 1000秒后自动解锁
boolean getUserLock = userLock.tryLock(1, 1000, TimeUnit.MILLISECONDS);
if (getUserLock) {
//业务逻辑的代码,通常在插入修改的操作方法上进行加锁
}catch (Exception e){
//提示
System.out.println("接令频繁"+ userId);
throw new ResultInfo(ResultUtils.error("接令频繁,请稍后再试"));
}finally {
//解锁
if (userLock.isLocked()) {
if (userLock.isHeldByCurrentThread()) {
userLock.unlock();
}
}
}
return null;
}
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