Ajax front-end and back-end interaction implementation methods using JSON

This article mainly introduces examples of jQuery Ajax front-end and back-end interaction using JSON. The front-end transmits json to the back-end through jQuery Ajax. The back-end receives json, processes the json, and the back-end returns a json to the front-end. If you are interested, you can Find out more, hope it helps everyone.

Requirements:

The front end transmits json to the back end through jQuery Ajax, the back end receives json, processes the json, and the back end returns a json to the front end

How to use servlet here

1. Use $.post method

index.jsp page

 <%@ page contentType="text/html; charset=UTF-8"%>      
  用户ID:   
 传输  

CheckServlet.Java code is as follows

package com.ajax; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class CheckServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /*设置字符集为'UTF-8'*/ request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); String userid = request.getParameter("userid"); // 接收userid String sex = request.getParameter("sex");//接收性别 System.out.println(userid); System.out.println(sex); //写返回的JSON PrintWriter pw = response.getWriter(); String json = "{'success':'成功','false':'失败'}"; pw.print(json); pw.flush(); pw.close(); } }

Since the servlet method is used here, web.xml must be configured

  Ajax  CheckServlet com.ajax.CheckServlet   CheckServlet /Ajax/CheckServlet  

Enter an ID on the page, which can be received and printed in the background. The background uses PrintWriter to write back JSON and returns it to the front end. The front end uses eval to convert JSON into an Object object, and obtains the JSON value through obj.name

2. Using the $.get method, you only need to change the post in the jsp page to get

 <%@ page contentType="text/html; charset=UTF-8"%>      
  用户ID:   
 传输  

The result is the same as $.post

3. Through the $.ajax method

 <%@ page contentType="text/html; charset=UTF-8"%>      
  用户ID:   
 传输  

$.ajax method can also be divided into post and get methods. Modify the sending method by modifying the type

The result is the same as method 1

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