guava限流

<!--限流-->
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.5</version>
</dependency>
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjrt</artifactId>
    <version>1.9.5</version>
</dependency>
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>16.0.1</version>
</dependency>

============================================================================

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

    double limitNum() default 20;  //速率

}

============================================================================

@Component
@Scope
@Aspect
public class RateLimitAspect {

    private Logger log = LoggerFactory.getLogger(this.getClass());
    //用来存放不同接口的RateLimiter(key为接口名称，value为RateLimiter)
    private ConcurrentHashMap<String, RateLimiter> map = new ConcurrentHashMap<>();

    private static ObjectMapper objectMapper = new ObjectMapper();

    private RateLimiter rateLimiter;

    @Autowired
    private HttpServletResponse response;

    @Pointcut("@annotation(com.yunting.consumer.sandconsumer.annotation.RateLimit)")
    public void serviceLimit() {
    }

    @Around("serviceLimit()")
    public Object around(ProceedingJoinPoint joinPoint) throws NoSuchMethodException {
        Object obj = null;
        //获取拦截的方法名
        Signature sig = joinPoint.getSignature();
        //获取拦截的方法名
        MethodSignature msig = (MethodSignature) sig;
        //返回被织入增加处理目标对象
        Object target = joinPoint.getTarget();
        //为了获取注解信息
        Method currentMethod = target.getClass().getMethod(msig.getName(), msig.getParameterTypes());
        //获取注解信息
        RateLimit annotation = currentMethod.getAnnotation(RateLimit.class);
        double limitNum = annotation.limitNum(); //获取注解每秒加入桶中的token
        String functionName = msig.getName(); // 注解所在方法名区分不同的限流策略

        //获取rateLimiter
        if(map.containsKey(functionName)){
            rateLimiter = map.get(functionName);
        }else {
            map.put(functionName, RateLimiter.create(limitNum));
            rateLimiter = map.get(functionName);
        }

        try {
            if (rateLimiter.tryAcquire()) {
                //执行方法
                obj = joinPoint.proceed();
            } else {
                //拒绝了请求（服务降级）
                String result = objectMapper.writeValueAsString(Result.build(500, "慢点,慢点,太快了！"));
                log.error("拒绝了请求：" + result);
                outErrorResult(result);
            }
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }
        return obj;
    }
    //将结果返回
    public void outErrorResult(String result) {
        response.setContentType("application/json;charset=UTF-8");
        try (ServletOutputStream outputStream = response.getOutputStream()) {
            outputStream.write(result.getBytes("utf-8"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    static {
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    }

}

============================================================================

@PostMapping("/user/xx/xx")
@RateLimit(limitNum = 100)
public Result gitftConsume(@RequestBody GiftConsumeDto giftConsumeDto)