在javascript中获取json数组对象

Question

Hi how to get json array elements in different ids in response?

//server side jsp

 <%@page import="net.sf.json.JSONObject"%>
<%@page import="net.sf.json.JSONArray"%>
<%
  JSONArray arrayObj=new JSONArray();               
 JSONObject obj=new JSONObject();
 obj.put("name","data");// how can i display string "name" in secondcombobox id?
 obj.put("roll_no","data"); how can i display string "roll_no" in thirdcombobox id?
 out.println(obj.toString());
%>

client side jsp where retrieving json array elements in javascript

 $("#firstcombo").change(function() {
 $.get('comboboxpage.jsp', { combo1Val : $(this).val() }, function(responseData) {
 $("#secondcomboboxid").replaceWith(data.name);// here i want to display name, how can i do it?
 $("#thirdcomboboxid").replaceWith(data.roll_no);// here i want to display roll no, how can i do it?
});
});

<input type="text" id="secondcomboboxid" name="secondcomboboxid"/>// how can i show name here?
<input type="text" id="thirdcomboboxid" name="thirdcomboboxid"/> how can i show roll_no here?

How can i display name in secondcomboboxid and roll no in thirdcomboboxid ? I googled a lot but could not find any solution, Any ideas please

Answer 1

If you are loading JSON data, you'd better use the method .getJSON() that will take care of parsing the response to a JSON object automatically.

Then you response data being an object, you can access its properties with the dot notation: data.name.

Special case thought for the second property "roll no". As there is a white space, you would have to use the array notation to access the value: data['roll no'].

$.getJSON('comboboxpage.jsp', { combo1Val : $(this).val() }, function(data) {
    $("#secondcomboboxid").replaceWith(data.name);
    $("#thirdcomboboxid").replaceWith(data['roll_no']);
});

More generally, as mentionned by @diEcho, to parse a json string, you can use $.parseJSON()

Answer 2

use

responseData.name
responseDate.roll_no

or use parseJSON

var obj = jQuery.parseJSON('{"name":"John"}');
alert( obj.name === "John" );

Answer 3

So, if I get your setup correctly, you're handling eg, :8080 with some simple servlet and you want to give back JSON data via a jsp. I think this is not a great idea, but for prototyping, I suppose... Here's a possible just make it work :

<%  
    JSONArray arrayObj=new JSONArray();                       
    arrayObj.put("name");
    arrayObj.put("roll no");
    out.println(arrayObj.toString());
%>

See above for the front-end components.

Answer 4

try this

<%
          JSONObject arrayObj= new JSONObject();

           arrayObj.put("name","john");
           arrayObj.put("roll no","007");


          response.setContentType("application/json");
          response.getWriter().write(arrayObj.toString());

%>

client side

$.ajax({
url:'comboboxpage.jsp',
dataType:'json',
type:'GET',
success:function(data){
console.log(data);
},
error:function(jxhr){
console.log(jxhr.responseText);
}

}); 

here is a helpful link