将java字符串转换为json对象

Question

I have json object named 'jo' in the below code.I convert this json object to java string to return this json object as response.Then how i convert this string back to json object in the required format.Please help me.

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="java.sql.*"%>
<%@page import="java.util.*,java.util.ArrayList"%>
<%@page import="net.sf.json.JSONObject"%>
<%@page import="net.sf.json.JSONArray"%>
<%
    JSONArray cellarray = new JSONArray();
    JSONObject cellobj = null; //new JSONObject();
    JSONObject jo=new JSONObject();
    String country=request.getParameter("count");  
    try{
        Class.forName("com.mysql.jdbc.Driver").newInstance();  
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:
        3306/test","root","root");  
        Statement stmt = con.createStatement();  
        ResultSet rs = stmt.executeQuery("Select * from state 
        where countryid='"+country+"'");  
            while(rs.next()){
                cellobj = new JSONObject();
                cellobj.put("id", rs.getString(1));
                cellobj.put("name", rs.getString(3));
                cellarray.add(cellobj);
            }  
            jo.put("arrayName",cellarray);
            response.setContentType("application/json");
            response.setCharacterEncoding("UTF-8");
            response.getWriter().write(jo.toString());
        }
    catch(Exception e){
        System.out.println(e);
    }
%>

Answer 1

Your questions seems a bit messy + formating of your code is messy too. But as i understood you, in order to convert String back to JSONObject you can do

String someString= getResponseFromServer();
JSONObject jsonObject = new JSONObject(someString);
// and then do with jsonObject variable whatever you desire

Also as people sugested you can use java libraries such as GSON or JSONLib etc

Answer 2

use Code:

String returnString = jo.toString();

and send as response.

Answer 3

You can use various libraries for this task - i recommend using GSON . You can find good tutorials on their site too, here .

I would use a custom object, not a simple JSONObject - you can deserialize and store your objects this way easily.

Answer 4

使用JSONObject

JSONObject jsonObj = new JSONObject("String");

Answer 5

这应该可以解决问题

JSONObject jsonObject = JSONObject.fromObject(jo);

Answer 6

// String to Json Object
JSONObject jsonObject = new JSONObject(stringResponse);

// JsonObject to String
String string = jsonObject.toString();

Answer 7

Wherever you are receiving response , you can use the following code :

 JSONObject json= new JSONObject ( responseString );

Then you can process the same as Json object .

Like String id=json.put("id");

Answer 8

It is just a suggestion, I also faces like this issue.

Finally, I tried with GSON library. GSON is directly convert your JSONString to java class object.

Example:

String jsonString = {"phoneNumber": "8888888888"}

create a new class:

class Phone {

@SerializedName("phoneNumber")
private String phoneNumebr;


public void setPhoneNumber(String phoneNumebr) {
this.phoneNumebr = phoneNumebr;
}

public String getPhoneNumebr(){
return phoneNumber;
}

}

// in java

Gson gson = new Gson();
Phone phone = gson.fromJson(jsonString, Phone.class);

System.out.println(" Phone number is "+phone.getPhoneNumebr());