Spring Boot使用Redis实现分布式锁

在分布式系统中，分布式锁是一种解决并发问题的常用技术。Redis由于其高性能和丰富的特性，成为实现分布式锁的理想选择。本文将详细介绍如何在Spring Boot应用中使用Redis实现分布式锁。

一、环境准备

1. 安装Redis：确保已经安装并运行Redis服务。
2. Spring Boot项目：确保已经创建并配置好了Spring Boot项目。
3. 添加依赖：在 pom.xml中添加Spring Data Redis和Lettuce依赖。

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency><groupId>io.lettuce.core</groupId><artifactId>lettuce-core</artifactId>
</dependency>
​

二、Redis配置

在 application.properties或 application.yml文件中配置Redis连接信息。

spring.redis.host=localhost
spring.redis.port=6379
spring.redis.password=yourpassword # 如果Redis设置了密码
​

三、实现分布式锁

1. 创建Redis配置类

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;@Configuration
public class RedisConfig {@Beanpublic StringRedisTemplate stringRedisTemplate(RedisConnectionFactory factory) {return new StringRedisTemplate(factory);}@Beanpublic ValueOperations<String, String> valueOperations(StringRedisTemplate stringRedisTemplate) {return stringRedisTemplate.opsForValue();}
}
​

2. 创建分布式锁工具类

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Component;import java.util.concurrent.TimeUnit;@Component
public class RedisLock {@Autowiredprivate ValueOperations<String, String> valueOperations;private static final long LOCK_EXPIRE = 30L; // 锁过期时间，30秒private static final String LOCK_VALUE = "LOCKED";public boolean lock(String key) {Boolean success = valueOperations.setIfAbsent(key, LOCK_VALUE, LOCK_EXPIRE, TimeUnit.SECONDS);return success != null && success;}public void unlock(String key) {valueOperations.getOperations().delete(key);}
}
​

3. 使用分布式锁

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class LockController {@Autowiredprivate RedisLock redisLock;@GetMapping("/lock")public String lock() {String key = "myLock";if (redisLock.lock(key)) {try {// 业务逻辑Thread.sleep(2000); // 模拟业务处理时间return "Locked and processed";} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {redisLock.unlock(key);}} else {return "Failed to acquire lock";}return "Unexpected error";}
}
​