SpringBoot集成Redisson实现分布式锁的方法示例

SpringBoot集成Redisson实现分布式锁的方法示例

上篇 《SpringBoot 集成 redis 分布式锁优化》对死锁的问题进行了优化，今天介绍的是 redis 官方推荐使用的 Redisson ，Redisson 架设在 redis 基础上的 java 驻内存数据网格（In-Memory Data Grid），基于NIO的 Netty 框架上，利用了 redis 键值数据库。功能非常强大，解决了很多分布式架构中的问题。

github的wiki地址： https://github.com/redisson/redisson/wiki

官方文档： https://github.com/redisson/redisson/wiki/目录

项目代码结构图：

导入依赖

org.redisson

redisson

3.8.0

属性配置

在 application.properites 资源文件中添加单机&哨兵相关配置

server.port=3000

# redisson lock 单机模式

redisson.address=redis://127.0.0.1:6379

redisson.password=

#哨兵模式

#redisson.master-name= master

#redisson.password=

#redisson.sentinel-addresses=10.47.91.83:26379,10.47.91.83:26380,10.47.91.83:26381

注意：

这里如果不加 redis:// 前缀会报 URI 构建错误

Caused by: java-.URISyntaxException: Illegal character in scheme name at index 0

更多的配置信息可以去官网查看

定义Lock的接口定义类

package com.tuhu.thirdsample.service;

import org.redisson.api.RLock;

import java.util.concurrent.TimeUnit;

/**

* @author chendesheng

* @create 2019/10/12 10:48

*/

public interface DistributedLocker {

RLock lock(String lockKey);

RLock lock(String lockKey, int timeout);

RLock lock(String lockKey, TimeUnit unit, int timeout);

boolean tryLock(String lockKey, TimeUnit unit, int waitTime, int leaseTime);

void unlock(String lockKey);

void unlock(RLock lock);

}

Lock接口实现类

package com.tuhu.thirdsample.service;

import org.redisson.api.RLock;

import org.redisson.api.RedissonClient;

import java.util.concurrent.TimeUnit;

/**

* @author chendesheng

* @create 2019/10/12 10:49

*/

public class RedissonDistributedLocker implements DistributedLocker{

private RedissonClient redissonClient;

@Override

public RLock lock(String lockKey) {

RLock lock = redissonClient.getLock(lockKey);

lock.lock();

return lock;

}

@Override

public RLock lock(String lockKey, int leaseTime) {

RLock lock = redissonClient.getLock(lockKey);

lock.lock(leaseTime, TimeUnit.SECONDS);

return lock;

}

@Override

public RLock lock(String lockKey, TimeUnit unit ,int timeout) {

RLock lock = redissonClient.getLock(lockKey);

lock.lock(timeout, unit);

return lock;

}

@Override

public boolean tryLock(String lockKey, TimeUnit unit, int waitTime, int leaseTime) {

RLock lock = redissonClient.getLock(lockKey);

try {

return lock.tryLock(waitTime, leaseTime, unit);

} catch (InterruptedException e) {

return false;

}

}

@Override

public void unlock(String lockKey) {

RLock lock = redissonClient.getLock(lockKey);

lock.unlock();

}

@Override

public void unlock(RLock lock) {

lock.unlock();

}

public void setRedissonClient(RedissonClient redissonClient) {

this.redissonClient = redissonClient;

}

}

redisson属性装配类

package com.tuhu.thirdsample.common;

import lombok.Data;

import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.context.annotation.Configuration;

/**

* @author chendesheng

* @create 2019/10/11 20:04

*/

@Configuration

@ConfigurationProperties(prefix = "redisson")

@ConditionalOnProperty("redisson.password")

@Data

public class RedissonProperties {

private int timeout = 3000;

private String address;

private String password;

private int database = 0;

private int connectionPoolSize = 64;

private int connectionMinimumIdleSize=10;

private int slaveConnectionPoolSize = 250;

private int masterConnectionPoolSize = 250;

private String[] sentinelAddresses;

private String masterName;

}

SpringBoot自动装配类

package com.tuhu.thirdsample.configuration;

import com.tuhu.thirdsample.common.RedissonProperties;

import com.tuhu.thirdsample.service.DistributedLocker;

import com.tuhu.thirdsample.service.RedissonDistributedLocker;

import com.tuhu.thirdsample.util.RedissonLockUtil;

import org.apache.commons.lang3.StringUtils;

import org.redisson.Redisson;

import org.redisson.api.RedissonClient;

import org.redisson.config.Config;

import org.redisson.config.SentinelServersConfig;

import org.redisson.config.SingleServerConfig;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;

import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;

import org.springframework.boot.context.properties.EnableConfigurationProperties;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

/**

* @author chendesheng

* @create 2019/10/12 10:50

*/

@Configuration

@ConditionalOnClass(Config.class)

@EnableConfigurationProperties(RedissonProperties.class)

public class RedissonAutoConfiguration {

@Autowired

private RedissonProperties redissonProperties;

/**

* 哨兵模式自动装配

* @return

*/

@Bean

@ConditionalOnProperty(name="redisson.master-name")

RedissonClient redissonSentinel() {

Config config = new Config();

SentinelServersConfig serverConfig = config.useSentinelServers().addSentinelAddress(redissonProperties.getSentinelAddresses())

.setMasterName(redissonProperties.getMasterName())

.setTimeout(redissonProperties.getTimeout())

.setMasterConnectionPoolSize(redissonProperties.getMasterConnectionPoolSize())

.setSlaveConnectionPoolSize(redissonProperties.getSlaveConnectionPoolSize());

if(StringUtils.isNotBlank(redissonProperties.getPassword())) {

serverConfig.setPassword(redissonProperties.getPassword());

}

return Redisson.create(config);

}

/**

* 单机模式自动装配

* @return

*/

@Bean

@ConditionalOnProperty(name="redisson.address")

RedissonClient redissonSingle() {

Config config = new Config();

SingleServerConfig serverConfig = config.useSingleServer()

.setAddress(redissonProperties.getAddress())

.setTimeout(redissonProperties.getTimeout())

.setConnectionPoolSize(redissonProperties.getConnectionPoolSize())

.setConnectionMinimumIdleSize(redissonPropertiehttp://s.getConnectionMinimumIdleSize());

if(StringUtils.isNotBlank(redissonProperties.getPassword())) {

serverConfig.setPassword(redissonProperties.getPassword());

}

return Redisson.create(config);

}

/**

* 装配locker类，并将实例注入到RedissLockUtil中

* @return

*/

@Bean

DistributedLocker distributedLocker(RedissonClient redissonClient) {

DistributedLocker locker = new RedissonDistributedLocker();

((RedissonDistributedLocker) locker).setRedissonClient(redissonClient);

RedissonLockUtil.setLocker(locker);

return locker;

}

}

Lock帮助类

package com.tuhu.thirdsample.util;

import com.tuhu.thirdsample.service.DistributedLocker;

import org.redisson.api.RLock;

import java.util.concurrent.TimeUnit;

/**

* @author chendesheng

* @create 2019/10/12 10:54

*/

public class RedissonLockUtil {

private static DistributedLocker redissLock;

public static void setLocker(DistributedLocker locker) {

redissLock = locker;

}

/**

* 加锁

* @param lockKey

* @return

*/

public static RLock lock(String lockKey) {

return redissLock.lock(lockKey);

}

/**

* 释放锁

* @param lockKey

*/

public static void unlock(String lockKey) {

redissLock.unlock(lockKey);

}

/**

* 释放锁

* @param lock

*/

public static void unlock(RLock lock) {

redissLock.unlock(lock);

}

/**

* 带超时的锁

* @param lockKey

* @param timeout 超时时间 单位：秒

*/

public static RLock lock(String lockKey, int timeout) {

return redissLock.lock(lockKey, timeout);

}

/**

* 带超时的锁

* @param lockKey

* @param unit 时间单位

* @param timeout 超时时间

*/

public static RLock lock(String lockKey, TimeUnit unit , int timeout) {

return redissLock.lock(lockKey, unit, timeout);

}

/**

* 尝试获取锁

* @param lockKey

* @param waitTime 最多等待时间

* @param leaseTime 上锁后自动释放锁时间

* @return

*/

public static boolean tryLock(String lockKey, int waitTime, int leaseTime) {

return redissLock.tryLock(lockKey, TimeUnit.SECONDS, waitTime, leaseTime);

}

/**

* 尝试获取锁

* @param lockKey

* @param unit 时间单位

* @param waitTime 最多等待时间

* @param leaseTime 上锁后自动释放锁时间

* @return

*/

public static boolean tryLock(String lockKey, TimeUnit unit, int waitTime, int leaseTime) {

return redissLock.tryLock(lockKey, unit, waitTime, leaseTime);

}

}

控制层

package com.tuhu.thirdsample.task;

import com.tuhu.thirdsample.common.KeyConst;

import lombok.extern.slf4j.Slf4j;

import org.redisson.api.RLock;

import org.redisson.api.RedissonClient;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.TimeUnit;

/**

* @author chendesheng

* @create 2019/10/12 11:03

*/

@RestController

@RequestMapping("/lock")

@Slf4j

public class LockController {

@Autowired

RedissonClient redissonClient;

@GetMapping("/task")

public void task(){

log.info("task start");

RLock lock = redissonClient.getLock(KeyConst.REDIS_LOCK_KEY);

boolean getLock = false;

try {

if (getLock = lock.tryLock(0,5,TimeUnit.SECONDS)){

//执行业务逻辑

System.out.println("拿到锁干活");

}else {

log.info("Redisson分布式锁没有获得锁:{},ThreadName:{}",KeyConst.REDIS_LOCK_KEY,Thread.currentThread().getName());

}

} catch (InterruptedException e) {

log.error("Redisson 获取分布式锁异常,异常信息:{}",e);

}finally {

if (!getLock){

return;

}

//如果演示的话需要注释该代码;实际应该放开

//lock.unlock();

//log.info("Redisson分布式锁释放锁:{},ThreadName :{}", KeyConst.REDIS_LOCK_KEY, Thread.currentThread().getName());

}

}

}

RLock 继承自 java.util.concurrent.locks.Lock ，可以将其理解为一个重入锁，需要手动加锁和释放锁 。

来看它其中的一个方法：tryLock(long waitTime, long leaseTime, TimeUnit unit)

getLock = lock.tryLock(0,5,TimeUnit.SECONDS)

通过 tryLock() 的参数可以看出，在获取该锁时如果被其他线程先拿到锁就会进入等待，等待 waitTime 时间，如果还没用机会获取到锁就放弃，返回 false；若获得了锁，除非是调用 unlock 释放，那么会一直持有锁，直到超过 leaseTime 指定的时间。

以上就是 Redisson 实现分布式锁的核心方法，有人可能要问，那怎么确定拿的是同一把锁，分布式锁在哪？

这就是 Redisson 的强大之处，其底层还是使用的 Redis 来作分布式锁，在我们的RedissonManager中已经指定了 Redis 实例，Redisson 会进行托管，其原理与我们手动实现 Redis 分布式锁类似。

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