Redisson与SpringBoot整合_融极_redisson springboot

网络 02-07 5232

概述

实际开发中会遇到分布式锁的情况，解决方案有数据库（不推荐）、Redis（Redission 推荐）、zookeeper等。这里我们介绍redisson方案。官方解释，什么是redisson？ Redis Java Client with features of In-Memory Data Grid。

什么是redisson

redisson是一个在redis的java客户端，是在Redis基础上实现的数据网格功能。他不仅提供了一系列的分布式的Java常用对象，还提供了许多分布式服务。 redisson提供的api均以面向对象的操作方式，将key-value封装成我们熟悉的集合或者对象，我们可以通过这些API更方便的操作数据。同时它提供了多个实现了java.util.concurrent接口的集合类，让我们能在线程安全的环境下操作数据。其中redis的官网也将它纳入推荐使用的工具中。

pom依赖 <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.6.1</version> <relativePath/>  </parent> ...  <dependency> <groupId>org.redisson</groupId> <artifactId>redisson-spring-boot-starter</artifactId> <version>3.16.6</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> redission配置信息 spring.redis.cluster.nodes=${redis.nodes} spring.redis.database=6 spring.redis.timeout=30000 spring.redis.enableTransactionSupport=false spring.redis.password=${redis.password} spring.redis.lettuce.pool.max-wait=30000 spring.redis.lettuce.pool.max-active=100 spring.redis.lettuce.pool.min-idle=50 redisson客户端对象实例化 package com.example.springboot_redis.redis; import lombok.extern.slf4j.Slf4j; import org.redisson.Redisson; import org.redisson.api.RedissonClient; import org.redisson.config.Config; import org.springframework.boot.autoconfigure.data.redis.RedisProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * Redission配置类 */ @Slf4j @Configuration public class RedissionConfig { /** * redisson协议前缀 */ private static final String SCHEMA_PREFIX = "redis://"; /** * 锁超时时间 */ @Value("${spring.redis.lockTimeOut:30000}") private long lockWatchTimeOut; @Bean public RedissonClient redissonClient(RedisProperties redisProperties) { Config config = new Config(); RedisProperties.Sentinel sentinel = redisProperties.getSentinel(); RedisProperties.Cluster redisPropertiesCluster = redisProperties.getCluster(); if (redisPropertiesCluster != null) { //集群redis ClusterServersConfig clusterServersConfig = config.useClusterServers(); for (String cluster : redisPropertiesCluster.getNodes()) { clusterServersConfig.addNodeAddress(SCHEMA_PREFIX + cluster); } if (StringUtils.hasText(redisProperties.getPassword())) { clusterServersConfig.setPassword(redisProperties.getPassword()); } clusterServersConfig.setTimeout((int) redisProperties.getTimeout().toMillis()); clusterServersConfig.setPingConnectionInterval(30000); } else if (StringUtils.hasText(redisProperties.getHost())) { //单点redis SingleServerConfig singleServerConfig = config.useSingleServer(). setAddress(SCHEMA_PREFIX + redisProperties.getHost() + ":" + redisProperties.getPort()); if (StringUtils.hasText(redisProperties.getPassword())) { singleServerConfig.setPassword(redisProperties.getPassword()); } singleServerConfig.setTimeout((int) redisProperties.getTimeout().toMillis()); singleServerConfig.setPingConnectionInterval(30000); singleServerConfig.setDatabase(redisProperties.getDatabase()); } else if (sentinel != null) { //哨兵模式 SentinelServersConfig sentinelServersConfig = config.useSentinelServers(); sentinelServersConfig.setMasterName(sentinel.getMaster()); for (String node : sentinel.getNodes()) { sentinelServersConfig.addSentinelAddress(SCHEMA_PREFIX + node); } if (StringUtils.hasText(redisProperties.getPassword())) { sentinelServersConfig.setPassword(redisProperties.getPassword()); } sentinelServersConfig.setTimeout((int) redisProperties.getTimeout().toMillis()); sentinelServersConfig.setPingConnectionInterval(30000); sentinelServersConfig.setDatabase(redisProperties.getDatabase()); } config.setLockWatchdogTimeout(lockWatchTimeOut); return Redisson.create(config); } } 编写分布式锁工具类 package com.example.springboot_redis.redis; 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.stereotype.Component; import java.util.concurrent.TimeUnit; /** * 分布式Redis锁 */ @Slf4j @Component public class DistributedRedisLock { @Autowired private RedissonClient redissonClient; // 加锁 public Boolean lock(String lockName) { if (redissonClient == null) { log.info("DistributedRedisLock redissonClient is null"); return false; } try { RLock lock = redissonClient.getLock(lockName); // 锁15秒后自动释放，防止死锁 lock.lock(15, TimeUnit.SECONDS); log.info("Thread [{}] DistributedRedisLock lock [{}] success", Thread.currentThread().getName(), lockName); // 加锁成功 return true; } catch (Exception e) { log.error("DistributedRedisLock lock [{}] Exception:", lockName, e); return false; } } // 释放锁 public Boolean unlock(String lockName) { if (redissonClient == null) { log.info("DistributedRedisLock redissonClient is null"); return false; } try { RLock lock = redissonClient.getLock(lockName); lock.unlock(); log.info("Thread [{}] DistributedRedisLock unlock [{}] success", Thread.currentThread().getName(), lockName); // 释放锁成功 return true; } catch (Exception e) { log.error("DistributedRedisLock unlock [{}] Exception:", lockName, e); return false; } } } 功能测试 package com.example.springboot_redis.contoller; import com.example.springboot_redis.redis.DistributedRedisLock; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; /** * 分布式Redis锁测试controller */ @Slf4j @RestController @RequestMapping("/lock") public class LockTestController { private final String LOCK = "LOCK"; @Autowired private DistributedRedisLock distributedRedisLock; // 测试不释放锁 @GetMapping("/testLock") public void testLock() { for (int i = 0; i < 5; i++) { new Thread(() -> { distributedRedisLock.lock(LOCK); }).start(); } } // 实际业务开发使用分布式锁的方式 @PostMapping public void post() { try { if (distributedRedisLock.lock(LOCK)) { // 业务逻辑 log.info("开始业务逻辑"); } else { // 处理获取锁失败的逻辑 log.info("获取锁失败"); } } catch (Exception e) { log.error("处理异常：", e); } finally { distributedRedisLock.unlock(LOCK); } } } 测试结果 2021-12-17 15:03:14.243 INFO 64496 --- [ Thread-21] com.study.practice.utils.DistributeLock : Thread [Thread-21] DistributedRedisLock lock [LOCK] success 2021-12-17 15:03:29.243 INFO 64496 --- [ Thread-23] com.study.practice.utils.DistributeLock : Thread [Thread-23] DistributedRedisLock lock [LOCK] success 2021-12-17 15:03:44.246 INFO 64496 --- [ Thread-20] com.study.practice.utils.DistributeLock : Thread [Thread-20] DistributedRedisLock lock [LOCK] success 2021-12-17 15:03:59.250 INFO 64496 --- [ Thread-19] com.study.practice.utils.DistributeLock : Thread [Thread-19] DistributedRedisLock lock [LOCK] success 2021-12-17 15:04:14.255 INFO 64496 --- [ Thread-22] com.study.practice.utils.DistributeLock : Thread [Thread-22] DistributedRedisLock lock [LOCK] success 结果分析调用方法启用5个线程，每个线程都去获取分布式锁，只有一个线程能获取到锁，其他线程均处于阻塞状态因为没有调用释放锁的方法，且在获取锁的lock（）方法中设置了锁的最大时间为15秒（防止死锁的发生），所以在15秒后锁自动释放，由其他线程进行竞争这把分布式锁然后执行。总结

在实际使用redission作为分布式锁时，操作步骤如下：

调用distributedRedisLock.lock(String lockName) 获取分布式锁；如果返回true，执行业务逻辑。如果返回false，进行阻塞；当执行完业务逻辑后，调用distributedRedisLock.unlock(String lockName)释放锁。参考

SprinBoot2.2.x 整合 Redission （分布式锁） Redisson实现分布式锁(1)—原理