防止重复提交

防止重复提交

前端

节流

• 解释：持续触发高频事件，函数每n秒执行一次。

• 业务场景

  输入框的模糊查询

• 目的

  节约流量、内存的损耗，旨在提升性能，在高频率频发的事件中才会用到。

防抖

持续触发高频事件，函数只会执行一次。

后端

• 目的：防止绕过前端校验持续访问接口。

• 实现

  1. 切面类

     package com.xiaoruiit.common.aop;
     
     import com.alibaba.druid.util.StringUtils;
     import com.xiaoruiit.common.utils.IPUtil;
     import com.xiaoruiit.common.utils.IdWorker;
     import com.xiaoruiit.common.utils.Result;
     import org.aspectj.lang.ProceedingJoinPoint;
     import org.aspectj.lang.annotation.Around;
     import org.aspectj.lang.annotation.Aspect;
     import org.aspectj.lang.reflect.MethodSignature;
     import org.springframework.beans.factory.annotation.Autowired;
     import org.springframework.data.redis.core.RedisTemplate;
     import org.springframework.stereotype.Component;
     import org.springframework.web.context.request.RequestContextHolder;
     import org.springframework.web.context.request.ServletRequestAttributes;
     
     import javax.servlet.http.HttpServletRequest;
     import java.lang.reflect.Method;
     import java.util.concurrent.TimeUnit;
     
     /**
      * @author hxr
      */
     @Component
     @Aspect // 定义切面类
     public class AvoidDuplicateSubmitAspect {
         @Autowired
         private RedisTemplate redisTemplate;
     
         @Around("@annotation(com.xiaoruiit.common.aop.AvoidDuplicateSubmit)")
         public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
             // 获取request对象
             HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest();
             String ip = IPUtil.getIP(request);
             // 获取方法签名
             MethodSignature signature = (MethodSignature) joinPoint.getSignature();
             Method method = signature.getMethod();
     
             String className = method.getDeclaringClass().getName();
             String methodName = method.getName();
             String ipKey = String.format("%s#%s", className, methodName);
             int hashCode = Math.abs(ipKey.hashCode());
             // 拼接redisKey,如：127.0.0.1_1234984393
             String redisKey = String.format("%s_%d", ip, hashCode);
     
             String value = (String) redisTemplate.opsForValue().get(redisKey);
             if (!StringUtils.isEmpty(value)) {
                 return Result.validateFailed("请勿重复提交");
             }
     
             // 获取注解
             AvoidDuplicateSubmit avoidDuplicateSubmit = method.getAnnotation(AvoidDuplicateSubmit.class);
             long timeout = avoidDuplicateSubmit.timeout();
             if (timeout < 0) {
                 timeout = 5000;
             }
             // 第一次提交，插入redis
             redisTemplate.opsForValue().set(redisKey, IdWorker.nextId(), timeout, TimeUnit.MILLISECONDS);
             // 继续执行方法
             return joinPoint.proceed();
         }
     
     }

  2. 注解

     package com.xiaoruiit.common.aop;
     
     import java.lang.annotation.ElementType;
     import java.lang.annotation.Retention;
     import java.lang.annotation.RetentionPolicy;
     import java.lang.annotation.Target;
     
     /**
      * @author hxr
      */
     @Target(ElementType.METHOD)
     @Retention(RetentionPolicy.RUNTIME)
     public @interface AvoidDuplicateSubmit {
         /**
          * 指定时间内不可重复提交，单位毫秒
          * @return
          */
         long timeout() default 5000;
     }

• 使用

  方法上加注解 @AvoidDuplicateSubmit
  @AvoidDuplicateSubmit  默认时间5000毫秒
  @AvoidDuplicateSubmit(timeout = 100000) 单位毫秒自己设置控制时间

获取IP真实地址

代理服务器结合java代码

• 1.nginx配置

  参考：https://segmentfault.com/a/1190000019197577

• java代码

  private static final String[] HEADERS_TO_TRY = {
              "X-Forwarded-For",
              "Proxy-Client-IP",
              "WL-Proxy-Client-IP",
              "HTTP_X_FORWARDED_FOR",
              "HTTP_X_FORWARDED",
              "HTTP_X_CLUSTER_CLIENT_IP",
              "HTTP_CLIENT_IP",
              "HTTP_FORWARDED_FOR",
              "HTTP_FORWARDED",
              "HTTP_VIA",
              "REMOTE_ADDR" };
  
  private String getClientIpAddress(HttpServletRequest request) {
      for (String header : HEADERS_TO_TRY) {
          String ip = request.getHeader(header);
          if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
              return ip;
          }
      }
  
      return request.getRemoteAddr();
  }