ratelimit+aop自定义注解实现应用限流

1、基于springboot项目pom.xml添加如下依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>18.0</version>
</dependency>
<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-redis</artifactId>
</dependency>

2、创建自定义注解：

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

    /**
     *
     * @return
     */
    String value() default "";

    /**
     * 每秒向桶中放入令牌的数量   默认最大即不做限流
     * @return
     */
    double perSecond() default Double.MAX_VALUE;

    /**
     * 获取令牌的等待时间  默认0
     * @return
     */
    int timeOut() default 0;

    /**
     * 超时时间单位
     * @return
     */
    TimeUnit timeOutUnit() default TimeUnit.MILLISECONDS;
}

3、创建aop切面进行环绕通知：

@Aspect
@Component
public class LxRateLimitAspect {

    private final static Logger logger = LoggerFactory.getLogger(LxRateLimitAspect.class);

    private RateLimiter rateLimiter = RateLimiter.create(Double.MAX_VALUE);

    /**
     * 定义切点
     * 1、通过扫包切入
     * 2、带有指定注解切入
     */
//    @Pointcut("execution(public * com.ycn.springcloud.*.*(..))")
    @Pointcut("@annotation(com.ycn.springcloud.annotation.LxRateLimit)")
    public void checkPointcut() { }

    @ResponseBody
    @Around(value = "checkPointcut()")
    public Object aroundNotice(ProceedingJoinPoint pjp) throws Throwable {
        logger.info("拦截到了{}方法...", pjp.getSignature().getName());
        Signature signature = pjp.getSignature();
        MethodSignature methodSignature = (MethodSignature)signature;
        //获取目标方法
        Method targetMethod = methodSignature.getMethod();
        if (targetMethod.isAnnotationPresent(LxRateLimit.class)) {
            //获取目标方法的@LxRateLimit注解
            LxRateLimit lxRateLimit = targetMethod.getAnnotation(LxRateLimit.class);
            rateLimiter.setRate(lxRateLimit.perSecond());
            if (!rateLimiter.tryAcquire(lxRateLimit.timeOut(), lxRateLimit.timeOutUnit()))
                return "服务器繁忙，请稍后再试!";
        }
        return pjp.proceed();
    }
}

4、接口调用自定义注解：

@RequestMapping("/testAnnotation")
@LxRateLimit(perSecond = 1.0, timeOut = 500)
public String testAnnotation() {
    return "get token success";
}

5、运行效果：

ratelimit+aop自定义注解实现应用限流

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