Json_Ajax 页面交互双向传值

1. json 跟字符串,数组,map,bean之间的数据转换

    1) JsonObject 

package com.Ip.Ie;

import java.util.HashMap;
import java.util.Map;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class JsonObject {
	public static void main(String[] args) {
	String json1 = "{'result':'1', 'returnval':'获取成功', 'recordcount':1, 'table':{'no':1}}";
	JSONObject j = JSONObject.fromObject(json1);
	System.out.println(j.get("returnval"));
	
	String json2 = "{'result':'1', 'returnval':[{'id':'9'},{'name':'Jack'}]}";
	JSONObject r = JSONObject.fromObject(json2);
	System.out.println(JSONObject.fromObject(JSONArray.fromObject(r.get("returnval")).get(1)).get("name"));
	
	Map<String,String> mp = new HashMap<String, String>();
	mp.put("firstName", "firstName");
	mp.put("lastName", "lastName");
	JSONObject json3 = JSONObject.fromObject(mp);
	System.out.println(json3.get("firstName"));
	
	boolean[] booarry=new boolean[]{true,false,true};
	JSONArray json4=JSONArray.fromObject(booarry);
	System.out.println(json4.get(2));
	
	Shop shop = new Shop("Marry", "金钟路");
	JSONObject json5 = JSONObject.fromObject(shop);
	System.out.println(json5.get("name"));
	
	String shopResult = "{'name':'Marry2','property':'金钟路2'}";
	JSONObject json6 = JSONObject.fromObject(shopResult);
	Shop shop2 = (Shop) JSONObject.toBean(json6,Shop.class);
	System.out.println(shop2.getProperty());
	
	
	}
}

    2) Shop

package com.Ip.Ie;

public class Shop {
private String name;
private String property;
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public String getProperty() {
	return property;
}
public void setProperty(String property) {
	this.property = property;
}
public Shop() {
}
public Shop(String name, String property) {
	this.name = name;
	this.property = property;
}

}

2. json 和后台数据的双向交互

    1) Serlvet 中间层

package com.servlet;

import java.io.*;
import java.net.*;
import java.text.ParseException;
import javax.servlet.*;
import javax.servlet.http.*;
//import net.sf.json.*;

import net.sf.json.JSONObject;

import java.io.*;
import java.net.*;
import java.text.ParseException;
import javax.servlet.*;
import javax.servlet.http.*;
//import net.sf.json.*;
 
public class JSONExample extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
	String line = null;
	StringBuffer json = new StringBuffer();
	 try {
         BufferedReader reader = req.getReader();
         while((line = reader.readLine()) != null) {
             json.append(line);
         }
     }
     catch(Exception e) {
         System.out.println("Error reading JSON string: " + e.toString());
     }
    JSONObject Json = JSONObject.fromObject(json.toString());
	System.out.println(Json.get("sex"));
	PrintWriter out = resp.getWriter();
	out.append("{'Name':'Machel'}");
	out.flush();
	out.close();
	//super.service(req, resp);
}
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        String json = readJSONStringFromRequestBody(request);
 
        //Use the JSON-Java binding library to create a JSON object in Java
        JSONObject jsonObject = null;
        try {
            //如果是用json-lib的话,前面引进的包改为
            //import  net.sf.json.*;   //这里改为
            //jsonObject = JSONObject.fromObject(json);
            //fromObject(object)是static的。也可以用fromString(string)的，但官方是不建议用fromString的。
            jsonObject = JSONObject.fromObject(json);
        }
        catch(Exception pe) {
            System.out.println("ParseException: " + pe.toString());
        }
 
        String responseText = "You have a " + jsonObject.getInt("year") + " "
            + jsonObject.getString("make") + " " + jsonObject.getString("model")
            + " " + " that is " + jsonObject.getString("color") + " in color.";
 
        response.setContentType("text/xml");
        response.getWriter().print(responseText);
    }
 
    private String readJSONStringFromRequestBody(HttpServletRequest request){
        StringBuffer json = new StringBuffer();
        String line = null;
        try {
            BufferedReader reader = request.getReader();
            while((line = reader.readLine()) != null) {
                json.append(line);
            }
        }
        catch(Exception e) {
            System.out.println("Error reading JSON string: " + e.toString());
        }
        return json.toString();
    }
}

    2) ajax 页面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'ajax.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
    <div οnclick="loadXMLDoc()">click</div>
    <span id="span"></span>
    <div id="myDiv"></div>
  </body>
  	<script type="text/javascript">
  function loadXMLDoc()
  {
  var htmlText = "{'sex':'man'}";
  var xmlhttp;
  if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
  else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
  xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    var TextHttp = xmlhttp.responseText;
    var obj = eval ("(" + TextHttp + ")");
    document.getElementById("myDiv").innerHTML=obj.Name;
    }
  }
xmlhttp.open("POST","/IP/JSONExample/JSONExample?wtd=delete",true);
xmlhttp.send(htmlText);
}
</script>
</html>

3. json 需要支持的包