A Volley adapter for JSON requests that will be parsed into Java objects by Gson.

GsonRequest.java

import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkResponse;
import com.android.volley.ParseError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.toolbox.HttpHeaderParser;

import java.io.UnsupportedEncodingException;
import java.util.Map;

/**
 * Volley adapter for JSON requests that will be parsed into Java objects by Gson.
 */
public class GsonRequest<T> extends Request<T> {
    private final Gson gson = new Gson();
    private final Class<T> clazz;
    private final Map<String, String> headers;
    private final Listener<T> 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<T> clazz, Map<String, String> headers,
            Listener<T> listener, ErrorListener errorListener) {
        super(Method.GET, url, errorListener);
        this.clazz = clazz;
        this.headers = headers;
        this.listener = listener;
    }

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

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

    @Override
    protected Response<T> 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));
        }
    }
}

Hi, We can do like this inside Response?
//=================
Type listType = new TypeToken(){}.getType(); // compiler error

return gson.fromJson(jsonString, listType);

//=================
Source: http://stackoverflow.com/questions/5370768/using-a-generic-type-with-gson

Is there a way to create a GsonRequest that delivers an ArrayList of an Object?

Like when you do:

Type type = new TypeToken<ArrayList<Example>>(){}.getType();
ArrayList<Example> = gson.fromJson(jsonString, type);

This is great! Thanks :)

Thank you!!

thanks ficus!

@ficusk Is there a way to handle gzip responses using volley? If I make a string request, the response appears to be scrambled and it loses its gzip encoding.

Nevermind, I figured it out https://gist.github.com/testtubebaby/8526542

@steindekker i get the same problem with you
this code is fail:
return Response.success(gson.fromJson(json, typeOfT), HttpHeaderParser.parseCacheHeaders(response));

thanks！

thanks,

I love you dear

Thanks

@ficusk Hi, We can do like this inside Response?
Type listType = new TypeToken(){}.getType(); // compiler error

@steindekker You can parse Json Array like this:

Type type = new TypeToken<ArrayList<Example>>(){}.getType();
ArrayList<Example> list = gson.fromJson(jsonString, type);

 ListExample listEx = new ListExample ();
 listEx.setList(list);

 // T  t = Primitives.wrap(clazz).cast(listEx);    cast your list into corresponding Class type
                
 return Response.success(Primitives.wrap(clazz).cast(listEx),
                        HttpHeaderParser.parseCacheHeaders(response));

Where T relate to 'ListExample.java' class mentioned below :

public class ListExample {

    List<Example> list;

    public List<Example> getList() {
        return list;
    }

    public void setList(List<Example> list) {
        this.list = list;
    }
}

You can send request like this:

GsonRequest<ListExample> jsonObjReq = new GsonRequest<ListExample>("Your Request Url",
                    ListExample.class, null, new Response.Listener<ListExample>() {
                @Override
                public void onResponse(ListExample response) {	 
		      List<Example> list = response.getList();
                     // Do your stuff here
                }
            },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                           // Do your stuff here
                        }
                    });

@zicjin try this, it's worked for me