making a GSON request using volley

Question

I have the following json response

{
  \"tag\": [
    {
      \"listing_count\": 5,
      \"listings\": [
        {
          \"source\": \"source1\",
               


        

Answer 1

Just create a GsonRequest Class as follows (taken from Android Developer Docs)

public class GsonRequest extends Request {
private final Gson gson = new Gson();
private final Class clazz;
private final Map headers;
private final Listener listener;

/**
 * Make a GET request and return a parsed object from JSON.
 *
 * @param url URL of the request to make
 * @param clazz Relevant class object, for Gson's reflection
 * @param headers Map of request headers
 */
public GsonRequest(String url, Class clazz, Map headers,
        Listener listener, ErrorListener errorListener) {
    super(Method.GET, url, errorListener);
    this.clazz = clazz;
    this.headers = headers;
    this.listener = listener;
}

@Override
public Map getHeaders() throws AuthFailureError {
    return headers != null ? headers : super.getHeaders();
}

@Override
protected void deliverResponse(T response) {
    listener.onResponse(response);
}

@Override
protected Response parseNetworkResponse(NetworkResponse response) {
    try {
        String json = new String(
                response.data,
                HttpHeaderParser.parseCharset(response.headers));
        return Response.success(
                gson.fromJson(json, clazz),
                HttpHeaderParser.parseCacheHeaders(response));
    } catch (UnsupportedEncodingException e) {
        return Response.error(new ParseError(e));
    } catch (JsonSyntaxException e) {
        return Response.error(new ParseError(e));
    }
}
} 

Now in your class file (Activity) just call the this class as follows:

RequestQueue queue = MyVolley.getRequestQueue();
GsonRequest myReq = new GsonRequest(Method.GET,
                                                    "http://JSONURL/",
                                                    TagList.class,
                                                    createMyReqSuccessListener(),
                                                    createMyReqErrorListener());

            queue.add(myReq);

We also need to create two methods -

1. createMyReqSuccessListener() - receive the response from GsonRequest
2. createMyReqErrorListener() - to handle any error

as follows:

private Response.Listener createMyReqSuccessListener() {
    return new Response.Listener() {
        @Override
        public void onResponse(MyClass response) {
           // Do whatever you want to do with response;
           // Like response.tags.getListing_count(); etc. etc.
        }
    };
}

and

private Response.ErrorListener createMyReqErrorListener() {
    return new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            // Do whatever you want to do with error.getMessage();
        }
    };
}

I hope it will make some sense.