Save JSON obj via Jfilechooser

I have my textfields which contains numbers, and i collected that numbers and place them into my json object.

Code :

---

JSONObject obj = new JSONObject();
	String prvi = textField.getText();
	int prvi1 = Integer.parseInt(prvi);
	String drugi = textField_1.getText();
	int drugi1 = Integer.parseInt(drugi);
	obj.put("lambda", new Integer (prvi1));
	obj.put("mttr", new Integer(drugi1));

---

i can use filewriter to save but it has only default folder.

Code :

---

try {
		FileWriter file = new FileWriter("c:\\test.json");
		file.write(obj.toJSONString());
		file.flush();
		file.close();
	} catch (IOException e) {
		e.printStackTrace();
	}
 
	System.out.print(obj);
}

---

i have to save that object via Jfile chooser i suppose

Code :

---

	JFileChooser chooser = new JFileChooser();
		int returnVal = chooser.showSaveDialog(chooser);
		if(returnVal == JFileChooser.APPROVE_OPTION) {
                .....
		}

---

I have no clue how to make my chooser to use that object and save it.
Little help please