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Redisson分布式锁全攻略：用法、场景与要点

news 来源：原创 2025/4/22 0:14:09

1. 普通可重入锁（RLock）

2. 公平锁（RFairLock）

3. 读写锁(RReadWriteLock)

4. 多重锁(RedissonMultiLock)

1. 普通可重入锁（RLock）

import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;public class RedissonLockExample {public static void main(String[] args) {// 配置 Redisson 客户端Config config = new Config();config.useSingleServer().setAddress("redis://127.0.0.1:6379");// 创建 Redisson 客户端实例RedissonClient redisson = Redisson.create(config);// 获取锁实例RLock lock = redisson.getLock("myLock");try {// 尝试获取锁，最多等待 100 秒，锁持有时间为 10 秒boolean isLocked = lock.tryLock(100, 10, TimeUnit.SECONDS);if (isLocked) {// 执行业务逻辑System.out.println("Lock acquired by " + Thread.currentThread().getName());// 模拟业务逻辑处理Thread.sleep(5000);} else {System.out.println("Failed to acquire lock");}} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {// 释放锁if (lock.isHeldByCurrentThread()) {lock.unlock();System.out.println("Lock released by " + Thread.currentThread().getName());}}// 关闭 Redisson 客户端redisson.shutdown();}
}

应用场景

电商秒杀系统：多个用户同时请求购买商品，通过分布式锁确保同一时间只有一个用户能够成功下单。
分布式任务调度：多个节点同时运行任务，通过锁确保任务的唯一性。

注释说明

tryLock 方法：尝试获取锁，可以指定等待时间和锁的持有时间。
isHeldByCurrentThread 方法：检查当前线程是否持有锁，避免误释放。
unlock 方法：释放锁，确保在 finally 块中调用，防止资源泄漏。

2. 公平锁（RFairLock）

示例代码

import org.redisson.Redisson;
import org.redisson.api.RFairLock;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;public class RedissonFairLockExample {public static void main(String[] args) {// 配置 Redisson 客户端Config config = new Config();config.useSingleServer().setAddress("redis://127.0.0.1:6379");// 创建 Redisson 客户端实例RedissonClient redisson = Redisson.create(config);// 获取公平锁实例RFairLock lock = redisson.getFairLock("myFairLock");try {// 尝试获取锁，最多等待 100 秒，锁持有时间为 10 秒boolean isLocked = lock.tryLock(100, 10, TimeUnit.SECONDS);if (isLocked) {// 执行业务逻辑System.out.println("Fair lock acquired by " + Thread.currentThread().getName());// 模拟业务逻辑处理Thread.sleep(5000);} else {System.out.println("Failed to acquire fair lock");}} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {// 释放锁if (lock.isHeldByCurrentThread()) {lock.unlock();System.out.println("Fair lock released by " + Thread.currentThread().getName());}}// 关闭 Redisson 客户端redisson.shutdown();}
}

应用场景

资源分配系统：多个线程或节点请求资源，通过公平锁确保按请求顺序获取资源。
队列处理系统：多个消费者处理队列中的任务，确保任务按顺序处理。

注释说明

公平锁特点：按照请求顺序获取锁，避免饥饿现象。
tryLock 方法：与普通锁类似，但公平锁会按照请求顺序排队。

3. 读写锁(RReadWriteLock)

示例代码

import org.redisson.Redisson;
import org.redisson.api.RReadWriteLock;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;public class RedissonReadWriteLockExample {public static void main(String[] args) {// 配置 Redisson 客户端Config config = new Config();config.useSingleServer().setAddress("redis://127.0.0.1:6379");// 创建 Redisson 客户端实例RedissonClient redisson = Redisson.create(config);// 获取读写锁实例RReadWriteLock readWriteLock = redisson.getReadWriteLock("myReadWriteLock");// 模拟读操作Thread readThread = new Thread(() -> {try {readWriteLock.readLock().lock();System.out.println("Read lock acquired by " + Thread.currentThread().getName());// 模拟读操作Thread.sleep(2000);} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {readWriteLock.readLock().unlock();System.out.println("Read lock released by " + Thread.currentThread().getName());}});// 模拟写操作Thread writeThread = new Thread(() -> {try {readWriteLock.writeLock().lock();System.out.println("Write lock acquired by " + Thread.currentThread().getName());// 模拟写操作Thread.sleep(2000);} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {readWriteLock.writeLock().unlock();System.out.println("Write lock released by " + Thread.currentThread().getName());}});// 启动线程readThread.start();writeThread.start();try {readThread.join();writeThread.join();} catch (InterruptedException e) {Thread.currentThread().interrupt();}// 关闭 Redisson 客户端redisson.shutdown();}
}

应用场景

缓存系统：多个线程读取缓存，少数线程更新缓存，通过读写锁提高并发性能。
数据库查询与更新：多个线程查询数据库，少数线程更新数据库。

注释说明

读锁共享：多个线程可以同时获取读锁。
写锁独占：写锁获取后，其他线程无法获取读锁或写锁。
锁的释放：确保在 finally 块中释放锁，避免死锁。

4. 多重锁(RedissonMultiLock)

示例代码

import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.redisson.api.RedissonMultiLock;
import org.redisson.config.Config;public class RedissonMultiLockExample {public static void main(String[] args) {// 配置 Redisson 客户端Config config = new Config();config.useSingleServer().setAddress("redis://127.0.0.1:6379");// 创建 Redisson 客户端实例RedissonClient redisson = Redisson.create(config);// 获取多个锁实例RLock lock1 = redisson.getLock("myLock1");RLock lock2 = redisson.getLock("myLock2");// 创建多重锁RedissonMultiLock multiLock = new RedissonMultiLock(lock1, lock2);try {// 尝试获取多重锁，最多等待 100 秒，锁持有时间为 10 秒boolean isLocked = multiLock.tryLock(100, 10, TimeUnit.SECONDS);if (isLocked) {// 执行业务逻辑System.out.println("Multi lock acquired by " + Thread.currentThread().getName());// 模拟业务逻辑处理Thread.sleep(5000);} else {System.out.println("Failed to acquire multi lock");}} catch (InterruptedException e) {Thread.currentThread().interrupt();} finally {// 释放多重锁if (multiLock.isHeldByCurrentThread()) {multiLock.unlock();System.out.println("Multi lock released by " + Thread.currentThread().getName());}}// 关闭 Redisson 客户端redisson.shutdown();}
}