Java-Redis-Redisson分布式锁的功能使用及实现

2022-11-13 14:11:22 java

前置

Java-Redis-Redisson配置基础上我们进行了改造,让锁的使用更加方便

基础设施

RedissonLock

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface RedissonLock {
    int lockTime() default 3; //加锁的时间默认3秒,  如果任务在3秒内执行完毕那么自动释放锁,如果任务3秒内没有执行完毕也会释放锁, 所以内容执行时间过长适当加大锁的时间
    String key() default "" ;  //唯一标识,如果没有那么默认为token->sessionId
    String doc() default "重复提交请求,请稍后再试";
    boolean repeatLock() default false; //可重复加锁直到加锁成功,默认为false不能重复加锁
    int repeatLockCount() default -1; //可重复加锁限制加锁的次数, 默认-1直到成功,设置10那么加锁10次都没成功就直接返回
    int lockWaitTimeMs() default 100; //重复加锁默认的阻塞时间100毫秒,可以自己定义
}

RepeatSubmitAspect

import com.application.Result;
import com.commonutils.NullUtils;
import com.redis.utils.DistributedRedisLock;
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.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
import org.springframework.WEB.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.Http.httpservletRequest;
@Aspect
@Component
public class RepeatSubmitAspect {
    @Value("${spring.redis.redisson.tokenName}")
    private  String tokenName;
    @Autowired
    private DistributedRedisLock redisLock;
    @Pointcut("@annotation(noRepeatSubmit)")
    public void pointCut(RedissonLock noRepeatSubmit) {
    }
    public static HttpServletRequest getRequest() {
        ServletRequestAttributes ra= (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        return ra.getRequest();
    }
    @Around("pointCut(noRepeatSubmit)")
    public Object around(ProceedingJoinPoint pjp, RedissonLock noRepeatSubmit) throws Throwable {
        int lockSeconds = noRepeatSubmit.lockTime();
        String doc = noRepeatSubmit.doc();
        String keyName = noRepeatSubmit.key();
        boolean b = noRepeatSubmit.repeatLock();
        int repeatLockCount = noRepeatSubmit.repeatLockCount();
        int lockWaitTimeMs = noRepeatSubmit.lockWaitTimeMs();
        HttpServletRequest request = getRequest();
        Assert.notNull(request, "request can not null");
        //如果没有唯一表示那么就使用token或者sessionID来唯一表示
        if(!NullUtils.notEmpty(keyName)){
            String token = request.getHeader(tokenName);
            if(NullUtils.notEmpty(token)){
                keyName=token;
            }else{
                //使用sessionID (注意保证分布式session共享)
                keyName = request.getSession().getId();
            }
            System.out.println("tokenName:"+keyName);
        }
        String path = request.getServletPath();
        String key = geTKEy(keyName, path);
        //加锁
        boolean isSuccess = redisLock.acquire(key, lockSeconds,b,repeatLockCount,lockWaitTimeMs);
        if (isSuccess) {
            // 获取锁成功
            Object result;
            try {
                // 执行
                result = pjp.proceed();
            } finally {
                // 解锁
                redisLock.release(key);
            }
            return result;
        } else {
            // 获取锁失败,认为是重复提交的请求
            return Result.Error(doc);
        }
    }
    private String getKey(String token, String path) {
        return token + path;
    }
}

DistributedRedisLock



import com.multithreading.utils.SleepTools;
import lombok.SneakyThrows;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.concurrent.TimeUnit;

@Component
public class DistributedRedisLock {
    private static final Logger logger = LoggerFactory.getLogger(DistributedRedisLock.class);
    //从配置类中获取redisson对象
    @Autowired
    private RedissonClient redissonClient;
    private final String LOCK_TITLE = "redisLock_";
    private final ThreadLocal<Integer> count = new ThreadLocal<>();//计数

    //加锁 , 线程加锁的时候发现,锁有人用了 ,那么就会进入自旋等待
    @SneakyThrows
    public boolean acquire(String lockKey, long seconds, boolean repeatLock, int repeatLockCount, int lockWaitTimeMs) {
        count.set(0); //初始化值
        //获取锁对象
        RLock mylock = redissonClient.getLock((LOCK_TITLE + lockKey));
        do {
            //尝试加锁
            boolean b = mylock.tryLock(0, seconds, TimeUnit.SECONDS);;
            if (b) {
                logger.info("获取锁成功");
                return true;
            }
            logger.info("尝试获取锁" + Thread.currentThread().getName());
            //获取加锁的次数,如果是-1那么持续加锁,如果满足加锁次数那么结束加锁
            if (repeatLockCount != -1 && count.get().equals(repeatLockCount)) {
                logger.warn(Thread.currentThread().getName() + "尝试加锁失败以尝试了:" + count.get() + "次");
                return false;
            }
            SleepTools.ms(lockWaitTimeMs);
            //加锁次数增加
            count.set(count.get() + 1);
        } while (repeatLock);
        logger.warn("重复提交");
        return false;
    }

    //手动锁的释放
    public void release(String lockKey) {
        //获取所对象
        RLock mylock = redissonClient.getLock((LOCK_TITLE + lockKey));
        // 这里判断下当前key是否上锁,不然业务执行时间大于锁自动释放时间后,解锁报异常
        if (mylock.isLocked()&&mylock.isHeldByCurrentThread()) { // 是否还是锁定状态并且锁是当前线程的
                mylock.unlock(); // 释放锁
                logger.info("解锁:" + lockKey);
        }

    }
}

功能使用和介绍

  • 支持配置锁的时间
  • 支持配置锁的key(同一个key的请求会被锁住)
  • 支持重复加锁
  • 支持重复加锁的次数
  • 支持重复加锁的间隔时间

通过以上功能的的组合能做到,幂等性,分布式悲观锁, 超时丢弃 ,不止在Controller里使用,而是在任何基于Spring容器管理的Bean都支持,当然如果特殊的场景我们可以直接使用DistributedRedisLock类,注意在任何时候都要释放锁

    
    @RedissonLock
    @GetMapping(value = "/updateAgeAsyncLock" )
    public Result updateAgeAsyncLock() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }

    
    @RedissonLock(doc = "加锁失败")
    @GetMapping(value = "/updateAgeAsyncLockDoc" )
    public Result updateAgeAsyncLockDoc() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }
    
    @RedissonLock(lockTime = 15)
    @GetMapping(value = "/updateAgeAsyncLock0" )
    public Result updateAgeAsyncLock0() {
         userService.updateAgeAsyncLock();
         return Result.Ok();
    }

    
    @RedissonLock(lockTime = 15,key = "updateAgeAsyncLock")
    @GetMapping(value = "/updateAgeAsyncLock1" )
    public Result updateAgeAsyncLock1() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }
    
    @RedissonLock(lockTime = 15,key = "updateAgeAsyncLock",repeatLock = true)
    @GetMapping(value = "/updateAgeAsyncLock2" )
    public Result updateAgeAsyncLock2() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }

    
    @RedissonLock(lockTime = 15,key = "updateAgeAsyncLock",repeatLock = true,repeatLockCount = 10)
    @GetMapping(value = "/updateAgeAsyncLock3" )
    public Result updateAgeAsyncLock3() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }
    
    @RedissonLock(lockTime = 15,key = "updateAgeAsyncLock",repeatLock = true,repeatLockCount = 10,lockWaitTimeMs = 500)
    @GetMapping(value = "/updateAgeAsyncLock4" )
    public Result updateAgeAsyncLock4() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }
    
    @RedissonLock(lockTime = 15,key = "updateAgeAsyncLock",repeatLock = true,lockWaitTimeMs = 500)
    @GetMapping(value = "/updateAgeAsyncLock4" )
    public Result updateAgeAsyncLock4() {
        userService.updateAgeAsyncLock();
        return Result.Ok();
    }

验证方式: 使用jmeter多线程10000请求 ,注意使用jmeter的时候不要使用默认锁key的方式,因为jmeter每次请sessionID都不同的,想要验证效果我们需要手动加key或者使用token

其他悲观锁的实现方式

public class DistributedRedisLock {
    //从配置类中获取redisson对象
    @Autowired
    private RedissonClient redissonClient;
    private  final String LOCK_TITLE = "redisLock_";
    //加锁 , 线程加锁的时候发现,锁有人用了 ,那么就会进入自旋等待
    public  boolean acquire(String lockName){
        //声明key对象
        String key = LOCK_TITLE + lockName;

        //获取锁对象
        RLock mylock = redissonClient.getLock(key);
        //一直等待直到加锁成功后,并且设置锁过期时间,防止死锁的产生
        mylock.lock(10, TimeUnit.SECONDS);
        System.err.println("======lock======"+Thread.currentThread().getName());
        //加锁成功
        return  true;
    }
    //锁的释放
    public    void release(String lockName){
        //必须是和加锁时的同一个key
        String key = LOCK_TITLE + lockName;
        //获取所对象
        RLock mylock = redissonClient.getLock(key);
     // 这里判断下当前key是否上锁,不然业务执行时间大于锁自动释放时间后,解锁报异常
        if(mylock.isLocked()){ // 是否还是锁定状态
            if(mylock.isHeldByCurrentThread()){ // 时候是当前执行线程的锁
                mylock.unlock(); // 释放锁
                System.err.println("======unlock======"+Thread.currentThread().getName());
            }
        }
    }
}

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