springmvc 自定義過濾器 過濾失敗返回自定義的信息

1、我們項目中會經常使用帶springmvc 的攔截器來校驗當前請求的前置規則，比如是不是有訪問權限，參數合法等。

2、攔截器說明：

　　我的項目是自定義類繼承 

org.springframework.web.servlet.handler.HandlerInterceptorAdapter，然后實現其中的三個前置、后置和最后渲染的攔截方法。主要業務一般寫在

preHandle（request,response,object）；方法中，比如參數校驗。

3、為了解決攔截失敗返回參數的一致性，我們需要返回自己的回調信息

 　　

package com.cloudstore.v4.interceptor;

import com.alibaba.fastjson.JSONObject;
import com.cloudstore.init.entity.initMember;
import com.cloudstore.init.service.initMemberService;
import com.cloudstore.v4.entity.TAuthMember;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;

public class AuthHandler extends HandlerInterceptorAdapter {

    @Autowired
    private initMemberService memberService;


    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        String ecId = httpServletRequest.getParameter("ecId");
        if(StringUtils.isEmpty(ecId)){
            writeFailure(httpServletResponse);
            return false;
        } 
        return true;
    }

    private void writeFailure(HttpServletResponse response) throws IOException {
        JSONObject result = new JSONObject();
        result.put("code",0);
        result.put("errMsg","對不起，你沒有權限!");
        response.setCharacterEncoding("UTF-8");
        PrintWriter writer = response.getWriter();
        writer.write(result.toString());
        writer.flush();
        writer.close();

    }

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

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

　

 

　以上是一個簡單的參數校驗。如果不為空就放過，否則，就返回{code:0,errMsg:'你沒有權限'}這樣的數據格式。和我們api的返回格式一樣