Springboot+Redis实现API接口限流的示例代码

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

spring:
  ## Redis
    redis:
      database: 0
      host: 127.0.0.1
      port: 6379
      password:
      jedis:
        pool:
          max-active: 8
          max-wait: -1ms
          max-idle: 8
          min-idle: 0
      timeout: 2000ms

@Inherited
@Documented
@Target({ElementType.FIELD,ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AccessLimit {

    //指定second 时间内 API请求次数
    int times() default 4;

    // 请求次数的指定时间范围  秒数(redis数据过期时间)
    int second() default 10;
}

import com.ys.xlb.annotation.AccessLimit;
import com.ys.xlb.bean.Code;
import com.ys.xlb.exception.GlobalException;
import com.ys.xlb.utils.IpUtils;
import com.ys.xlb.utils.RequestUtils;
import com.ys.xlb.utils.ResultUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;
import java.util.concurrent.TimeUnit;

/**
 * @ClassName AccessLimitInterceptor
 * @description: API请求限流拦截器
 * @time 2019-04-20 11:08
 **/
@Slf4j
@Component
public class AccessLimitInterceptor implements HandlerInterceptor {

    @Resource
    private RedisTemplate<String, Integer> redisTemplate;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        try{
            // Handler 是否为 HandlerMethod 实例
            if(handler instanceof HandlerMethod){
                // 强转
                HandlerMethod handlerMethod = (HandlerMethod) handler;
                // 获取方法
                Method method = handlerMethod.getMethod();
                // 是否有AccessLimit注解
                if(!method.isAnnotationPresent(AccessLimit.class)){
                    return true;
                }
                // 获取注解内容信息
                AccessLimit accessLimit = method.getAnnotation(AccessLimit.class);
                if(accessLimit == null){
                    return true;
                }
                int times = accessLimit.times();//请求次数
                int second = accessLimit.second();//请求时间范围
                //根据 IP + API 限流
                String key = IpUtils.getIpAddr(request) + request.getRequestURI();
                //根据key获取已请求次数
                Integer maxTimes = redisTemplate.opsForValue().get(key);
                if(maxTimes == null){
                    //set时一定要加过期时间
                    redisTemplate.opsForValue().set(key, 1, second, TimeUnit.SECONDS);
                }else if(maxTimes < times){
                    redisTemplate.opsForValue().set(key, maxTimes+1, second, TimeUnit.SECONDS);
                }else{
                    // 30405 API_REQUEST_TOO_MUCH  请求过于频繁
                    RequestUtils.out(response, ResultUtils.error(Code.API_REQUEST_TOO_MUCH));
                    return false;
                }
            }
        }catch (Exception e){
            log.error("API请求限流拦截异常,请检查Redis是否开启!",e);
            throw new GlobalException(Code.BAD_REQUEST,e.getMessage());
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

 /**
     * IpUtils工具类方法
     * 获取真实的ip地址
     * @param request
     * @return
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if(org.apache.commons.lang.StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
            //多次反向代理后会有多个ip值，第一个ip才是真实ip
            int index = ip.indexOf(",");
            if(index != -1){
                return ip.substring(0,index);
            }else{
                return ip;
            }
        }
        ip = request.getHeader("X-Real-IP");
        if(org.apache.commons.lang.StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)){
            return ip;
        }
        return request.getRemoteAddr();
    }

 /**
     * @Title: out
     * @Description:  response输出JSON数据
     * @param response : 响应请求
     * @param object: object
     * @return void
     **/
    public static void out(ServletResponse response, Object object){
        PrintWriter out = null;
        try {
            response.setContentType("application/json;charset=UTF-8");
            response.setCharacterEncoding("UTF-8");
            out = response.getWriter();
            out.println(JSONObject.fromObject(resultMap).toString());
        } catch (Exception e) {
            log.error("输出JSON报错!"+e);
        }finally{
            if(null != out){
                out.flush();
                out.close();
            }
        }
    }

@Configuration
public class ApplicationConfig implements WebMvcConfigurer {

 //这里需要注入拦截器 否则无法获取到拦截器注入的RedisTemplate<String, Integer> redisTemplate; 
 @Bean
    public AccessLimitInterceptor accessLimitInterceptor(){
        return new AccessLimitInterceptor();
    }

 /**
     * 配置拦截器
     * @author lance
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/**").excludePathPatterns("/static/**","/login.html","/user/login");
        //API限流拦截
        registry.addInterceptor(accessLimitInterceptor()).addPathPatterns("/**").excludePathPatterns("/static/**","/login.html");
    }
}

/**
     * @Title: selectAll
     * @Description: 查询文章信息
     **/
    @AccessLimit(times = 5)
    @RequestMapping(value = "selectAll" , method = {RequestMethod.GET,RequestMethod.POST})
    //GetMapping(value = "selectAll")
    public ResultBody selectAll(Article article) {
        return articleService.selectAll(article);
    }