SpringBoot在一定时间内限制接口请求次数的实现示例

<!-- AOP依赖 -->

< dependency >

             < groupId >org.springframework.boot</ groupId >

             < artifactId >spring-boot-starter-aop</ artifactId >

             < version >2.1.5.RELEASE</ version >

</ dependency >

<!-- Map依赖 -->

< dependency >

             < groupId >net.jodah</ groupId >

             < artifactId >expiringmap</ artifactId >

             < version >0.5.8</ version >

</ dependency >

@Documented

@Target (ElementType.METHOD) // 说明该注解只能放在方法上面

@Retention (RetentionPolicy.RUNTIME)

public @interface LimitRequest {

     long time() default 6000 ; // 限制时间 单位：毫秒

     int count() default 1 ; // 允许请求的次数

}

@Aspect

@Component

public class LimitRequestAspect {

     private static ConcurrentHashMap<String, ExpiringMap<String, Integer>> book = new ConcurrentHashMap<>();

     // 定义切点

     // 让所有有@LimitRequest注解的方法都执行切面方法

     @Pointcut ( "@annotation(limitRequest)" )

     public void excudeService(LimitRequest limitRequest) {

     }

     @Around ( "excudeService(limitRequest)" )

     public Object doAround(ProceedingJoinPoint pjp, LimitRequest limitRequest) throws Throwable {

         // 获得request对象

         RequestAttributes ra = RequestContextHolder.getRequestAttributes();

         ServletRequestAttributes sra = (ServletRequestAttributes) ra;

         HttpServletRequest request = sra.getRequest();

         // 获取Map对象， 如果没有则返回默认值

         // 第一个参数是key， 第二个参数是默认值

         ExpiringMap<String, Integer> uc = book.getOrDefault(request.getRequestURI(), ExpiringMap.builder().variableExpiration().build());

         Integer uCount = uc.getOrDefault(request.getRemoteAddr(), 0 );

         if (uCount >= limitRequest.count()) { // 超过次数，不执行目标方法

             return "接口请求超过次数" ;

         } else if (uCount == 0 ){ // 第一次请求时，设置有效时间

//            /** Expires entries based on when they were last accessed */

//            ACCESSED,

//            /** Expires entries based on when they were created */

//            CREATED;

             uc.put(request.getRemoteAddr(), uCount + 1 , ExpirationPolicy.CREATED, limitRequest.time(), TimeUnit.MILLISECONDS);

         } else { // 未超过次数， 记录加一

             uc.put(request.getRemoteAddr(), uCount + 1 );

         }

         book.put(request.getRequestURI(), uc);

         // result的值就是被拦截方法的返回值

         Object result = pjp.proceed();

         return result;

     }

}