SpringBoot利用限速器RateLimiter实现单机限流

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>

    <dependency>
      <groupId>cn.hutool</groupId>
      <artifactId>hutool-all</artifactId>
    </dependency>

    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
    </dependency>

server:
  port: 8080
  servlet:
    context-path: /demo

@SpringBootApplication
public class SpringBootDemoRatelimitGuavaApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootDemoRatelimitGuavaApplication.class, args);
    }
}

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RateLimiter {
    int NOT_LIMITED = 0;

    /**
     * qps (每秒并发量)
     */
    @AliasFor("qps") double value() default NOT_LIMITED;

    /**
     * qps (每秒并发量)
     */
    @AliasFor("value") double qps() default NOT_LIMITED;

    /**
     * 超时时长,默认不等待
     */
    int timeout() default 0;

    /**
     * 超时时间单位,默认毫秒
     */
    TimeUnit timeUnit() default TimeUnit.MICROSECONDS;
}

@Slf4j
@Aspect
@Component
public class RateLimiterAspect {
    /**
     * 单机缓存
     */
    private static final ConcurrentMap<String, com.google.common.util.concurrent.RateLimiter> RATE_LIMITER_CACHE = new ConcurrentHashMap<>();

    /**
      这里记得改成你自己注解实际的包路径,我看有些小伙伴说报错, 就是路径不对识别不到
    */
    @Pointcut("@annotation(com.**.RateLimiter)")
    public void rateLimit() {

    }

    @Around("rateLimit()")
    public Object pointcut(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();
        // 通过 AnnotationUtils.findAnnotation 获取 RateLimiter 注解
        RateLimiter rateLimiter = AnnotationUtils.findAnnotation(method, RateLimiter.class);
        if (rateLimiter != null && rateLimiter.qps() > RateLimiter.NOT_LIMITED) {
            double qps = rateLimiter.qps();
            // TODO 这个key可以根据具体需求配置,例如根据ip限制,或用户
            String key = method.getDeclaringClass().getName() + StrUtil.DOT + method.getName();
            if (RATE_LIMITER_CACHE.get(key) == null) {
                // 初始化 QPS
                RATE_LIMITER_CACHE.put(key, com.google.common.util.concurrent.RateLimiter.create(qps));
            }

            // 尝试获取令牌
            if (RATE_LIMITER_CACHE.get(key) != null && !RATE_LIMITER_CACHE.get(key).tryAcquire(rateLimiter.timeout(), rateLimiter.timeUnit())) {
                throw new RuntimeException("手速太快了，慢点儿吧~");
            }
        }
        return point.proceed();
    }
}

@Slf4j
@RestController
public class TestController {

    /**
     * 接口每秒只能请求一次,不等待
     * @return
     */
    @RateLimiter(value = 1.0)
    @GetMapping("/test1")
    public Dict test1() {
        log.info("【test1】被执行了。。。。。");
        return Dict.create().set("msg", "hello,world!").set("description", "别想一直看到我，不信你快速刷新看看~");
    }

    /**
     * 接口每秒只能请求一次,等待一秒
     * @return
     */
    @RateLimiter(value = 1.0, timeout = 1,timeUnit = TimeUnit.SECONDS)
    @GetMapping("/test3")
    public Dict test3() {
        log.info("【test3】被执行了。。。。。");
        return Dict.create().set("msg", "hello,world!").set("description", "别想一直看到我，不信你快速刷新看看~");
    }
}