Springboot使用redis进行api防刷限流过程详解

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

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface AccessLimit {
  int seconds();
  int maxCount();
  boolean needLogin() default true;
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class AccessLimtInterceptor implements HandlerInterceptor {

  @Autowired
  private RedisService redisService;

  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

    if (handler instanceof HandlerMethod) {
      HandlerMethod hm = (HandlerMethod) handler;
      AccessLimit accessLimit = hm.getMethodAnnotation(AccessLimit.class);
      if (null == accessLimit) {
        return true;
      }
      int seconds = accessLimit.seconds();
      int maxCount = accessLimit.maxCount();
      boolean needLogin = accessLimit.needLogin();

      if (needLogin) {
        //判断是否登录
      }

      String key = request.getContextPath() + ":" + request.getServletPath() + ":" + ip ;

      Integer count = redisService.get(key);

      if (null == count || -1 == count) {
        redisService.set(key, 1);
        redisService.expire(seconds);
        return true;
      }

      if (count < maxCount) {
        redisService.inCr(key);
        return true;
      }

      if (count >= maxCount) {
//        response 返回 json 请求过于频繁请稍后再试
        return false;
      }
    }

    return true;
  }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

// extends WebMvcConfigurerAdapter 已经废弃，java 8开始直接继承就可以
@Configuration
public class IntercepterConfig implements WebMvcConfigurer {
  @Autowired
  private AccessLimtInterceptor accessLimtInterceptor;

  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(accessLimtInterceptor)
        .addPathPatterns("/拦截路径")
        .excludePathPatterns("/不被拦截路径 通常为登录注册或者首页");
  }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("test")
public class TestControler {

  @GetMapping("accessLimit")
  @AccessLimit(seconds = 3, maxCount = 10)
  public String testAccessLimit() {
    //xxxx
    return "";
  }
}