springboot中设计基于Redisson的分布式锁注解

如何使用AOP设计一个分布式锁注解？

1、在pom.xml中配置依赖

        <dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId><version>5.3.26</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-aop</artifactId></dependency>

2、逻辑代码

创建一下多个文件夹，并复制粘贴进代码

2.1、RedissonConfig.java

需要配置一下Redisson

import org.redisson.Redisson;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** Redisson 配置**/
@Configuration
public class RedissonConfig {@Beanpublic RedissonClient redissonClient() {Config config = new Config();config.useSingleServer().setAddress("redis://192.168.57.111:6379") // Redis地址.setPassword(null) // 如果没有密码，设置为null.setDatabase(0); // 使用的Redis数据库索引RedissonClient redissonClient = Redisson.create(config);// 测试连接try {redissonClient.getKeys().count();System.out.println("Redisson connected to Redis successfully.");} catch (Exception e) {System.err.println("Failed to connect to Redis: " + e.getMessage());}return redissonClient;}
}

需要修改setAddress("redis://192.168.57.111:6379")中的地址为自己的redis地址

2.2、DistributedLock.java

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Target(ElementType.METHOD) // 作用于方法
@Retention(RetentionPolicy.RUNTIME) // 注解在运行时生效
public @interface DistributedLock {String prefix() default "lock:"; // 锁前缀，默认为 "lock:"String key() default ""; // 锁的Key，支持SpEL表达式long leaseTime() default 30; // 锁的默认持有时间，单位秒long waitTime() default 10; // 获取锁的等待时间，单位秒
}

2.3、DistributedLockAspect.java

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.concurrent.TimeUnit;@Aspect
@Component
public class DistributedLockAspect {@Autowiredprivate RedissonClient redissonClient; // 注入 Redisson 客户端/*** 定义切入点，匹配所有使用 @DistributedLock 注解的方法* @param distributedLock 分布式锁注解对象*/@Pointcut("@annotation(distributedLock)")public void distributedLockPointcut(DistributedLock distributedLock) {}/*** 环绕通知：在目标方法执行前后处理分布式锁逻辑** @param joinPoint 切点，表示目标方法的执行点* @param distributedLock 注解，用于获取注解属性值* @return 目标方法的返回值* @throws Throwable 当目标方法抛出异常时向上抛出*/@Around("distributedLockPointcut(distributedLock)")public Object around(ProceedingJoinPoint joinPoint, DistributedLock distributedLock) throws Throwable {String lockKey = buildLockKey(distributedLock.prefix(),distributedLock.key(), joinPoint); // 生成锁KeyRLock lock = redissonClient.getLock(lockKey);boolean isLocked = false;try {while (true) {// 尝试获取锁isLocked = lock.tryLock(distributedLock.waitTime(), distributedLock.leaseTime(), TimeUnit.SECONDS);if (isLocked) {System.out.println(Thread.currentThread().getName() + " 成功获取锁，key: " + lockKey);return joinPoint.proceed(); // 执行目标方法} else {System.out.println(Thread.currentThread().getName() + " 未获取到锁，key: " + lockKey + "，重试中...");// 等待一段时间后再重试Thread.sleep(500);}}} finally {if (isLocked && lock.isHeldByCurrentThread()) {lock.unlock(); // 释放锁System.out.println(Thread.currentThread().getName() + " 已释放锁，key: " + lockKey);}}}private String buildLockKey(String prefix, String key, ProceedingJoinPoint joinPoint) {if (key.isEmpty()) {throw new IllegalArgumentException("Lock key cannot be empty");}// 拼接锁前缀和原始键String rawKey = prefix + key;// 将拼接后的键通过 MD5 生成唯一的锁键return generateMD5(rawKey);}/*** 使用 MD5 生成锁键* @param input 原始键* @return MD5 生成的锁键*/private String generateMD5(String input) {try {MessageDigest md = MessageDigest.getInstance("MD5");byte[] digest = md.digest(input.getBytes());// 转换为 32 位十六进制字符串StringBuilder hexString = new StringBuilder();for (byte b : digest) {String hex = Integer.toHexString(0xff & b);if (hex.length() == 1) {hexString.append('0');}hexString.append(hex);}return hexString.toString();} catch (NoSuchAlgorithmException e) {throw new RuntimeException("Failed to generate MD5 hash", e);}}}

这三步做完之后，该注解就能用了。

3、业务模拟测试

根据以下创建文件，并写入代码

3.1、InventoryService.java

这里测试可以itemId为键加锁

import com.pshao.charplatform.utils.distributedLock.DistributedLock;
import org.springframework.stereotype.Service;@Service
public class InventoryService {@DistributedLock(prefix = "stock",key = "#itemId", leaseTime = 10, waitTime = 1)public void reduceStock(Long itemId, int quantity) {System.out.println(Thread.currentThread().getName() + " 正在处理库存扣减: itemId=" + itemId + ", quantity=" + quantity);try {Thread.sleep(2000); // 模拟耗时操作，修改为两秒} catch (InterruptedException e) {e.printStackTrace();}System.out.println(Thread.currentThread().getName() + " 完成库存扣减: itemId=" + itemId);}}

这里可以输入以下多个参数，key是必须的，其他可以不输入

String prefix() default "lock:"; // 锁前缀，默认为 "lock:"
String key() default ""; // 锁的Key
long leaseTime() default 30; // 锁的默认持有时间，单位秒
long waitTime() default 10; // 获取锁的等待时间，单位秒

3.2、DistributedLockApplication.java

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;@SpringBootApplication(scanBasePackages = "com.pshao.charplatform")
public class DistributedLockApplication {public static void main(String[] args) {ApplicationContext context = SpringApplication.run(DistributedLockApplication.class, args);InventoryService inventoryService = context.getBean(InventoryService.class);ExecutorService executor = Executors.newFixedThreadPool(3); // 创建3个线程// 模拟多个线程竞争同一资源for (int i = 0; i < 3; i++) {executor.submit(() -> inventoryService.reduceStock(123L, 10));}executor.shutdown();}
}

3.3、运行查看测试结果

测试成功！ 

如果运行后出现，类似以下日志

Action: Correct the classpath of your application so that it contains compatible versions of the classes org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator and org.springframework.util.ClassUtils

考虑是版本冲突，可以参考Correct the classpath of your application so that it contains compatible versions......版本不兼容解决方法-CSDN博客