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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