Java开发中的分布式锁使用教程

1. 基于ZooKeeper的分布式锁

1.1 引入依赖

在项目的pom.xml文件中添加以下依赖：

<dependency><groupId>org.apache.curator</groupId><artifactId>curator-framework</artifactId><version>latest</version>
</dependency>
<dependency><groupId>org.apache.curator</groupId><artifactId>curator-recipes</artifactId><version>latest</version>
</dependency>
<dependency><groupId>org.apache.zookeeper</groupId><artifactId>zookeeper</artifactId><version>latest</version>
</dependency>

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1.2 配置ZooKeeper连接

在application.yml中添加ZooKeeper连接配置：

spring:zookeeper:connect-string: localhost:2181namespace: demo

1.3 编写分布式锁实现类

@Component
public class DistributedLock {@Autowiredprivate CuratorFramework curatorFramework;public InterProcessMutex acquire(String lockPath, long waitTime, long leaseTime, TimeUnit timeUnit) throws Exception {InterProcessMutex lock = new InterProcessMutex(curatorFramework, lockPath);if (!lock.acquire(waitTime, timeUnit)) {throw new RuntimeException("获取分布式锁失败");}if (leaseTime > 0) {lock.acquire(leaseTime, timeUnit);}return lock;}public void release(InterProcessMutex lock) throws Exception {if (lock != null) {lock.release();}}
}

2. 基于Redis的分布式锁

2.1 添加Redisson依赖

在pom.xml中添加如下配置：

<dependency><groupId>org.redisson</groupId><artifactId>redisson-spring-boot-starter</artifactId><version>3.20.0</version>
</dependency>

2.2 配置Redisson连接

在Spring Boot项目的配置文件application.yml中添加Redisson配置：

spring:data:redis:host: localhostport: 6379database: 0redisson:codec: org.redisson.codec.JsonJacksonCodecsingle-server-config:address: "redis://${spring.data.redis.host}:${spring.redis.port}"database: "${spring.data.redis.database}"password: "${spring.data.redis.password}"

2.3 编写分布式锁代码类

import jakarta.annotation.Resource;
import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.springframework.stereotype.Service;
import java.util.concurrent.TimeUnit;@Service
public class RedissonLockService {@Resourceprivate Redisson redisson;public boolean tryLock(String key, long timeout, TimeUnit unit) {RLock lock = redisson.getLock(key);try {return lock.tryLock(timeout, unit);} catch (InterruptedException e) {Thread.currentThread().interrupt();return false;}}
}

3. 注意事项

ZooKeeper锁：利用临时节点与watch机制，每个锁占用一个普通节点/lock，当需要获取锁时在/lock目录下创建一个临时节点，创建成功则表示获取锁成功，失败则watch/lock节点，有删除操作后再去争锁。
Redisson锁：提供了原生的分布式锁实现，支持锁的自动续期和高性能，适合高并发场景。

以上是Java开发中分布式锁的基本使用教程，可以根据实际项目需求选择合适的实现方式。