JSONObject

volley-json.java

String url ="http://ip.jsontest.com/";

        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null,
                new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                etUser.setText("Response :" + response.toString());
            }
        }, new Response.ErrorListener(){
            @Override
            public void onErrorResponse(VolleyError error) {

            }
        });
        ServiceSingleton.getInstance(this).addToRequestQueue(jsonObjectRequest);