ajax用json完结多少传输

 JSON(JavaScript Object
Notation)
是一种轻量级的数据调换格式。它依照ECMAScript,ECMAScript的二个子集。
JSON采纳完全部独用立于言语的文本格式,不过也选拔了就好像于C语言家族的习惯(包罗C、C++、C#Java、JavaScript、PerlPython等)。那几个特点使JSON成为能够的数据沟通语言。
易于人读书和编辑,同时也易于机器解析和转变(一般用来升高网络传输速率)。

json不难说便是javascript中的对象和数组,所以那三种结构正是目的和数组二种结构,通过那二种结构可以表示各个繁复的构造。

一 、对象:对象在js中象征为“{}”括起来的内容,数据结构为
{key:value,key:value,…}的键值对的布局,在面向对象的言语中,key为对象的性质,value为对应的属性值,所以很不难掌握,取值方法为
对象.key 获取属性值,那些属性值的品种能够是
数字、字符串、数组、对象几种。

② 、数组:数组在js中是中括号“[]”括起来的剧情,数据结构为
[“java”,”javascript”,”vb”,…],取值情势和享有语言中千篇一律,使用索引获取,字段值的档次能够是
数字、字符串、数组、对象两种。

透过对象、数组2种结构就足以组合成复杂的数据结构了。

 

 

应用JSON前须求先的导入json.jar包

ECMAScript 1

传输单个对象:

新建二个 servlet

package com.itnba.maya.a;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONObject;

/**
 * Servlet implementation class C
 */
@WebServlet("/C")
public class C extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public C() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        //模拟从数据库中查处
        Dog a=new Dog();
        a.setName("小黄");
        a.setAge(5);
        a.setZl("哈士奇");

        JSONObject obj=new JSONObject();
        obj.put("name", a.getName());
        obj.put("age", a.getAge());
        obj.put("zl", a.getZl());

        JSONObject bb=new JSONObject();
        bb.put("obj", obj);

        response.getWriter().append(bb.toString());
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

效果如下:

ECMAScript 2

jsp页面

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script type="text/javascript" src="js/jquery-1.11.1.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
    $("#k").click(function(){
        $.ajax({
            url:"C",
            data:{},
            type:"POST",
            dataType:"JSON",
            success:function(httpdata){
                $("#x").append("<li>"+httpdata.obj.name+"</li>");
                $("#x").append("<li>"+httpdata.obj.age+"</li>");
                $("#x").append("<li>"+httpdata.obj.zl+"</li>")
            }
        })
    });
});
</script>
</head>
<body>
查看
<h1>
<ul id="x">
</ul></h1>
</body>
</html>

 效果如下:

ECMAScript 3

 传输集合或数组:

servlet:

package com.itnba.maya.a;

import java.io.IOException;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONArray;
import org.json.JSONObject;

/**
 * Servlet implementation class D
 */
@WebServlet("/D")
public class D extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public D() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        //模拟从数据库中查出
        Dog a1=new Dog();
        a1.setName("小黄");
        a1.setAge(5);
        a1.setZl("哈士奇");

        Dog a2=new Dog();
        a2.setName("中黄");
        a2.setAge(6);
        a2.setZl("泰迪");

        Dog a3=new Dog();
        a3.setName("大黄");
        a3.setAge(7);
        a3.setZl("京巴");

        ArrayList<Dog> list=new ArrayList<Dog>();
        list.add(a1);
        list.add(a2);
        list.add(a3);

        JSONArray arr= new JSONArray();
        //遍历集合
        for(Dog d:list){
            JSONObject obj=new JSONObject();
            obj.put("name", d.getName());
            obj.put("age", d.getAge());
            obj.put("zl", d.getZl());
            arr.put(obj);
        }

        response.getWriter().append(arr.toString());
    }


    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

 效果如下:

ECMAScript 4

jsp页面:

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script type="text/javascript" src="js/jquery-1.11.1.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
    $("#k").click(function(){
        $.ajax({
            url:"D",
            data:{},
            type:"POST",
            dataType:"JSON",
            success:function(httpdata){
                for(var i=0;i<httpdata.length;i++){
                    var n=httpdata[i].name
                    var a=httpdata[i].age
                    var z=httpdata[i].zl
                    var tr="<tr>"
                        tr+="<td>"+n+"</td>"
                        tr+="<td>"+a+"</td>"
                        tr+="<td>"+z+"</td>"
                        tr+="</tr>"
                        $("#x").append(tr)
                }    
            }
        })
    });
});
</script>

</head>
<body>
查看
<h1>
<table width="100%" id="x" border="1px">
</table>
</h1>
</body>
</html>

 

 效果如下:

ECMAScript 5