Parsing JSON Array within JSON Object

Question

I have some JSON with the following structure:

{"source":[            {"name":"john","age":20},            {"name":"michael","age":25},            {"name":"sara", "age":23}          ] } 

I have named this JSON string as mainJSON. I'm trying to access the elements "name" and "age" with the following Java code:

JSONArray jsonMainArr = new JSONArray(mainJSON.getJSONArray("source")); for (int i = 0; i < jsonMainArr.length(); i++) {  // **line 2**      JSONObject childJSONObject = jsonMainArr.getJSONObject(i);      String name = childJSONObject.getString("name");      int age     = childJSONObject.getInt("age"); } 

I'm being shown the following exception for line number 2:

org.json.JSONException: JSONArray initial value should be a string or collection or array. 

Please guide me as to where I'm making the mistake and how to rectify this.

Answer 1

mainJSON.getJSONArray("source") returns a JSONArray, hence you can remove the new JSONArray.

The JSONArray contructor with an object parameter expects it to be a Collection or Array (not JSONArray)

Try this:

JSONArray jsonMainArr = mainJSON.getJSONArray("source");  

Answer 2

Your code is fine, just replace the following line:

JSONArray jsonMainArr = new JSONArray(mainJSON.getJSONArray("source")); 

with this line:

JSONArray jsonMainArr = mainJSON.getJSONArray("source");