A Volley request class for easy parsing of JSON using Gson.

GsonRequest.java

/**
 * Copyright 2013 Adam Speakman
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package your.pkg.here;

import java.io.UnsupportedEncodingException;

import com.android.volley.NetworkResponse;
import com.android.volley.ParseError;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.toolbox.HttpHeaderParser;
import com.android.volley.toolbox.JsonRequest;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonSyntaxException;

public class GsonRequest<T> extends JsonRequest<T> {

    Class<T> mResponseClass;

    public GsonRequest(int method, String url, String requestBody, Class<T> responseClass, Listener<T> listener,
            ErrorListener errorListener) {
        super(method, url, requestBody, listener, errorListener);
        mResponseClass = responseClass;
        // Do some generic stuff in here - for example, set your retry policy to
        // longer if you know all your requests are going to take > 2.5 seconds
        // etc etc...
    }

    @Override
    protected Response<T> parseNetworkResponse(NetworkResponse networkResponse) {
        try {
            String jsonString = new String(networkResponse.data, HttpHeaderParser.parseCharset(networkResponse.headers));
            T response = new GsonBuilder().create().fromJson(jsonString, mResponseClass);
            com.android.volley.Response<T> result = com.android.volley.Response.success(response,
                    HttpHeaderParser.parseCacheHeaders(networkResponse));
            return result;
        } catch (UnsupportedEncodingException e) {
            return com.android.volley.Response.error(new ParseError(e));
        } catch (JsonSyntaxException e) {
            return com.android.volley.Response.error(new ParseError(e));
        }
    }

}