SpringBoot3+Redis+Lua脚本实现分布式锁
相关依赖包
xml
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<spring-boot.version>3.0.2</spring-boot.version>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
application.yml Redis配置
yml
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spring:
data:
redis:
host: 192.168.5.133
port: 6379
password:
database: 0
lettuce:
pool:
max-active: 8
max-idle: 8
min-idle: 0
max-wait: "-1ms"
Lua脚本
获取锁脚本 tryLock.lua
bash
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-- KEYS[1] 是锁的键
-- ARGV[1] 是请求ID
-- ARGV[2] 是锁的过期时间（秒）
local lockKey = KEYS[1]
local requestId = ARGV[1]
local expireTime = tonumber(ARGV[2])
-- 尝试获取锁
local lockValue = redis.call('GET', lockKey)
-- 如果锁不存在，尝试设置锁
if not lockValue then
if redis.call('SETNX', lockKey, requestId) then
-- 设置锁的过期时间
redis.call('EXPIRE', lockKey, expireTime)
return 1
end
return 0
elseif lockValue == requestId then
-- 如果请求ID与当前锁持有者匹配，延长锁的过期时间
redis.call('EXPIRE', lockKey, expireTime)
return 1
else
-- 锁被其他请求持有，无法获取锁
return 0
end
释放锁脚本 releaseLock.lua
bash
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-- KEYS[1] 是锁的键
-- ARGV[1] 是请求ID
local lockKey = KEYS[1]
local requestId = ARGV[1]
-- 获取锁的值
local lockValue = redis.call('GET', lockKey)
-- 检查请求ID是否匹配锁的持有者
if lockValue == requestId then
-- 删除锁
redis.call('DEL', lockKey)
return 1
else
return 0
end
Service层实现
java
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package pub.qingyun.service;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.stereotype.Service;
import java.util.List;
/**
* @author CQY
* @version 1.0
* @date 2024/7/10 10:29
**/
@Service
@Slf4j
public class RedisLockService {
private static final String LOCK_KEY = "distributed-lock";
@Resource
private StringRedisTemplate stringRedisTemplate;
private static final DefaultRedisScript<Long> TRY_LOCK_SCRIPT = new DefaultRedisScript<>();
private static final DefaultRedisScript<Long> RELEASE_LOCK_SCRIPT = new DefaultRedisScript<>();
static {
TRY_LOCK_SCRIPT.setScriptSource(new ResourceScriptSource(new ClassPathResource("script/tryLock.lua")));
TRY_LOCK_SCRIPT.setResultType(Long.class);
RELEASE_LOCK_SCRIPT.setScriptSource(new ResourceScriptSource(new ClassPathResource("script/releaseLock.lua")));
RELEASE_LOCK_SCRIPT.setResultType(Long.class);
}
/**
* 尝试获取分布式锁。
*
* @param requestId 请求ID，用于唯一标识锁的持有者。
* @param expireTime 锁的过期时间（秒）。
* @return 如果成功获取锁返回true，否则返回false。
*/
public boolean tryLock(String requestId, int expireTime) {
Object result = stringRedisTemplate.execute(TRY_LOCK_SCRIPT,
List.of(LOCK_KEY),
requestId,
String.valueOf(expireTime));
assert result != null;
return Long.parseLong(result.toString()) == 1L;
}
/**
* 释放分布式锁。
*
* @param requestId 请求ID，必须与获取锁时使用的相同。
* @return 如果锁成功释放返回true，否则返回false。
*/
public boolean releaseLock(String requestId) {
Object result = stringRedisTemplate.execute(RELEASE_LOCK_SCRIPT,
List.of(LOCK_KEY),
requestId);
assert result != null;
return Long.parseLong(result.toString()) == 1L;
}
}
Controller调用示例代码
java
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package pub.qingyun.controller;
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.RestController;
import pub.qingyun.service.RedisLockService;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
/**
* @author CQY
* @version 1.0
* @date 2024/7/10 10:43
**/
@Slf4j
@RestController
public class LuaLockController {
// Lock timeout in seconds
private static final int LOCK_TIMEOUT_SECONDS = 30000;
private final RedisLockService lockService;
@Autowired
public LuaLockController(RedisLockService lockService) {
this.lockService = lockService;
}
/**
* 尝试获取锁并执行一些操作，然后释放锁。
* 通过尝试获取锁来确保操作的原子性，避免并发问题
*/
@GetMapping("/performOperation")
public String performOperation() {
// 使用UUID作为请求ID
String requestId = UUID.randomUUID().toString();
try {
// 尝试获取锁
boolean tryLock = lockService.tryLock(requestId, LOCK_TIMEOUT_SECONDS);
log.info("获取锁[{}][{}]", requestId, tryLock);
if (tryLock) {
// 执行关键操作
log.info("开始执行主任务[{}]...", requestId);
TimeUnit.SECONDS.sleep(5); // 模拟耗时操作
log.info("任务[{}]执行完成", requestId);
return requestId + " completed successfully.";
} else {
log.info("无法获取锁，任务[{}]被拒绝", requestId);
return "无法获取锁，任务[" + requestId + "]被拒绝";
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
log.error("Interrupted while performing operation.", e);
return "任务[" + requestId + "]执行失败";
} finally {
// 释放锁
boolean releaseLock = lockService.releaseLock(requestId);
log.info("释放锁[{}][{}]", requestId, releaseLock);
}
}
}
SpringBoot3+Redisson实现分布式锁
添加依赖包
xml
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<dependency>
<groupId>org.redisson</groupId>
<artifactId>redisson-spring-boot-starter</artifactId>
<version>3.20.0</version>
</dependency>
配置类
java
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@Configuration
package pub.qingyun.config;
import org.redisson.Redisson;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;
import org.springframework.beans.factory.annotation.Value;
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.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
/**
* @author CQY
* @version 1.0
* @date 2024/7/5 10:58
**/
@Configuration
public class RedisConfig {
@Value("${spring.data.redis.host}")
private String host;
@Value("${spring.data.redis.port}")
private String port;
@Bean
public RedissonClient redissonClient() {
Config config = new Config();
config.useSingleServer().setAddress("redis://" + host + ":" + port + "");
return Redisson.create(config);
}
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(connectionFactory);
template.setKeySerializer(new StringRedisSerializer());
template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
template.afterPropertiesSet();
return template;
}
}
实现类
java
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@Resource
private RedissonClient redissonClient;
public void example() {
RLock rlock = redissonClient.getLock("myLock");
try {
boolean locked = rlock.tryLock(0, 800, TimeUnit.MILLISECONDS);
if (locked) {
// TODO
} else {
log.warn("Thread[{}]Could not acquire lock.", Thread.currentThread().getName());
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
log.error("Error occurred while trying to acquire lock.", e);
} finally {
if (rlock.isHeldByCurrentThread()) {
rlock.unlock();
}
}
}