使用Aop和自定义注解实现SpringTask定时任务中加锁逻辑的封装

SpringTask的定时任务，在集群环境下会多次执行，我们可以通过使用分布式锁的方式进行解决

    @Scheduled(cron = "1/10 * * * * ?")
    @Async
    public void updateGrassLikeNum() {
        RLock lock = redissonClient.getLock("like:lock");
        try {
            if (lock.tryLock(0, 0, TimeUnit.SECONDS)) {
                grassService.updateLikeNumTask();
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            if (lock.isHeldByCurrentThread() && lock.isLocked()) {
                lock.unlock();
            }
        }

    }

但是，项目中可能存在很多定时任务，每次使用RLock加锁比较麻烦，我们可以使用AOP+自定义注解的方式进行优化

自定义注解

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface LockAnnotation {

    /**
     * 锁名称
     *
     * @return
     */
    String lockName() default "";

    /**
     * 加锁等待时间
     *
     * @return
     */
    long lockWaitTime() default 0;

    /**
     * 锁超时时间
     *
     * @return
     */
    long lockTimeOut() default 0;
}

切面类

@Component
@Aspect
public class LockAspect {

    @Resource
    private RedissonClient redissonClient;

    // 切点
    @Pointcut("@annotation(com.qfedu.common.core.annotataion.LockAnnotation)")
    public void pointcut() {
    }

    // 环绕通知
    @Around("pointcut()")
    public Object around(ProceedingJoinPoint joinPoint) {
        // 获取被注解的方法
        MethodInvocationProceedingJoinPoint mjp = (MethodInvocationProceedingJoinPoint) joinPoint;
        MethodSignature signature = (MethodSignature) mjp.getSignature();
        Method method = signature.getMethod();

        Object ret = null;
        // 获取注解对应的对象
        LockAnnotation annotation = method.getAnnotation(LockAnnotation.class);
        if (annotation != null) {
            String lockName = annotation.lockName();
            long lockWaitTime = annotation.lockWaitTime();
            long lockTimeOut = annotation.lockTimeOut();

            RLock lock = redissonClient.getLock(lockName);
            try {
                if (lock.tryLock(lockWaitTime, lockTimeOut, TimeUnit.SECONDS)) {
                    // 调用目标方法
                    ret = joinPoint.proceed();
                }
            } catch (Throwable e) {
                throw new RuntimeException(e);
            } finally {
                if (lock.isHeldByCurrentThread() && lock.isLocked()) {
                    lock.unlock();
                }
            }
        }
        return ret;
    }

使用自定义注解的定时任务方法修改如下：

    @Scheduled(cron = "1/10 * * * * ?")
    @Async
    @LockAnnotation(lockName = "like:lock", lockWaitTime = 0, lockTimeOut = 10)
    public void updateGrassLikeNum() {
        grassService.updateLikeNumTask();

    }