详解Redis如何优雅地实现接口防刷

package main.java.com.shigen.redis.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy,
import java.lang.annotation.Target;

/**
 * @author shigenfu
 * @date 2023/9/6 10:05 上午
 */
 
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface RateLimit {
    
    /**
     * 限定时间
     * 
     * @return 限定时间
     */
     int seconds() default 1;
     /**
     * 最大请求数
     * 
     * @return 最大请求数!
     */
     int max() default 1;
}

/**
* @author shigenfu
* @date 2023/9/6  10:09  上午
*/

@Component
public class RateLimitIntercept extends HandlerInterceptorAdapter {
    
    @Resource
    private RedisTemplate<String, String> redisTemplate;
    public static final String RATE_LIMIT_KEY = "rl:",
    
    @Override
    public boolean preHandle(HttpServletRequest request,HttpServletResponse response,Object handler) throws IOException{
        // 请求是否是方法的请求
        if (handler instanceof HandlerMethod){
            HandlerMethod handlerMethod =(HandlerMethod) handler:
            // 获得注解
            RateLimit methodAnnotation = handlerMethod.getMethodAnnotation(RateLimit.class);
            if (methodAnnotation == null) {
                return true;
            }
            int seconds = methodAnnotation.seconds();
            int max = methodAnnotation.max();
            
            String key = RATE_LIMIT_KEY + request.getRemoteAddr()+ ":"+ request.getRequestURI();
            String times = redisTemplate.opsForValue().get(key);
            if (times = null) {
                redisTemplate.opsForValue().set(key, String.value0f(1), seconds, TimeUnit.SECONDS);
            }else{
                int timesInt = Integer.parseInt(times);
                if(timesInt < max){
                    redisTemplate.opsForValue().set(key, String.value0f(timesInt + 1), seconds, TimeUnit.SECONDs);
                }else{
                    response.sendError(429,"to many requests");
                    return false;
                }
            }
        }
        return true,
    }
}

/**
* @author shigenfu
* @date 2023/9/6 11:30 上午
*/

@Configuration
public class WebConfig implements WebMvcConfigurer {
    
    @Resource
    private RateLimitIntercept rateLimitIntercept;
    
    @Override
    public void addInterceptors(InterceptorRegistry registry){
        registry.addInterceptor(rateLimitIntercept),
    }
}

/**
 * @author shigenfu
 * @date 2023/9/6 11:25 上午
 */
 
@RestController
@RequestMapping(value ="rate")
public class RateLimitTestController {
    
    @GetMapping(value = "test")
    @RateLimit(seconds=10，max=2)
    public String test(){
        return UUID.randomUUID().toString();
    }
}

 ab -c 2 -n 10 127.0.0.1:9000/rate/test