写一个aop ，分布式锁

1. 先定义一个注解

   @Retention(RetentionPolicy.RUNTIME)
   @Target(ElementType.METHOD)
   public @interface MyLock {
       String name();
       long waitTime() default 0;
       long leaseTime() default -1;
       TimeUnit timeUnit() default TimeUnit.SECONDS;
   }

2. 再写一个切面

   @Slf4j
   @Aspect
   @Component
   public class MyLockAspect {
       @Around("@annotation(lock)")
       public Object lock(ProceedingJoinPoint pjp, MyLock lock) throws Throwable{
           log.info(lock.name());
           return pjp.proceed();
       }
   }

3. 然后在要被增强的方法上加上注解

   @MyLock(name="test-redison-lock", leaseTime = 10,timeUnit = TimeUnit.SECONDS)

4. 补全具体切面

   @Slf4j
   @Aspect
   @Component
   public class MyLockAspect {
       @Autowired
       private RedissonClient redissonClient;
   
       @Around("@annotation(myLock)")
       public Object lock(ProceedingJoinPoint pjp, MyLock myLock) throws Throwable {
           log.info(myLock.name());
           RLock lock = redissonClient.getLock(myLock.name());
           boolean locked = false;
           try {
               locked = lock.tryLock(myLock.waitTime(), myLock.leaseTime(), myLock.timeUnit());
               if (!locked) {
                   //没有获取到锁
                   throw new RuntimeException();
               } else {
                   return pjp.proceed();
               }
           } catch (Exception e) {
               throw new RuntimeException(e);
           } finally {
               if (locked) {
                   lock.unlock();
               }
           }
       }
   }