1、引入依赖
<!-- guava 限流 -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>25.1-jre</version>
</dependency>
2、自定义注解
@Target({ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ServiceLimit {
String description() default "";
}
3、AOP实现类
@Component
@Scope
@Aspect
public class LimitAspect {
////每秒只发出5个令牌，此处是单进程服务的限流,内部采用令牌捅算法实现
private static RateLimiter rateLimiter = RateLimiter.create(5.0);
//Service层切点 限流
@Pointcut("@annotation(com.itstyle.seckill.common.aop.ServiceLimit)")
public void ServiceAspect() {
}
@Around("ServiceAspect()")
public Object around(ProceedingJoinPoint joinPoint) {
Boolean flag = rateLimiter.tryAcquire();
Object obj = null;
try {
if(flag){
obj = joinPoint.proceed();
}
} catch (Throwable e) {
e.printStackTrace();
}
return obj;
}
}
4、使用
@Override
@ServiceLimit
@Transactional
public Result startSeckil(long seckillId,long userId) {
//todo 操作
}
