how-to-use-volley-string-request-in-android
String uri = String.format("http://somesite.com/some_endpoint.php?param1=%1$s¶m2=%2$s",
num1,
num2);
StringRequest myReq = new StringRequest(Method.GET,
uri,
createMyReqSuccessListener(),
createMyReqErrorListener());
queue.add(myReq);