ApiRequest.java

package com.ocelotty.memestream.Services;

import android.app.Activity;
import android.content.Context;

import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonObjectRequest;
import com.ocelotty.memestream.MainActivity;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.UnsupportedEncodingException;

public abstract class ApiRequest<T> {
    protected Context context;
    protected T activity;


    final String url = "http://memestream.herokuapp.com";
    final protected String client_id = "2a571d63f685bd2a9e7e82af192651692848b0e0ec19ae6b05194dd99ffa1500";
    final protected String client_secret = "78a0d630a90dd03dcf50f0b49b7b16894f820d864fc5b6a6ac3c0ce28857bfd6";
    final String api_path = "/api/v1";

    JsonObjectRequest request;

    protected String requestURI(String path) {
        return url + api_path + path;
    }

    protected JsonObjectRequest postRequest(JSONObject params, String uri) {
        request = new JsonObjectRequest(requestURI(uri), params,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            handleRequest(response);
                            VolleyLog.v("VOLLEY Response:%n %s", response.toString(4));
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        String strRespons = new String(error.networkResponse.data);
                        JSONObject errorObject;

                        try {
                            errorObject = new JSONObject(strRespons);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                        handleErrorRequest(VolleyErrorHelper.getMessage(error, context));
                    }
                }
        );

        return request;
    }

    protected JsonObjectRequest getRequest(String uri) {
        request = new JsonObjectRequest(requestURI(uri), null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            VolleyLog.v("Response:%n %s", response.toString(4));
                            handleRequest(response);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        VolleyLog.e("Error: %n %s", error.getMessage());
                        String errorRes = VolleyErrorHelper.getMessage(error, context);
                        handleErrorRequest(errorRes);
                    }
                }
        );

        return request;
    }

    protected void handleRequest(JSONObject response) {
    }

    protected void handleErrorRequest(String response) {
    }
}

RegistrationActivity

public class RegistrationActivity extends Activity implements UserRegistrationDelegator {
  public onClick(costam) {
    try
      {
        userRegistration = new UserRegistration(mEmail,mPassword,mPasswordConfirmation);
        ApplicationController.getInstance().addToRequestQueue(userRegistration.call(this));
      }
  }

  public void onUserRegistered(User user) {
        Intent k = new Intent(ApplicationController.getInstance().getApplicationContext(), MainActivity.class);
        startActivity(k);
        finish();
    }

    public void onUserRegistrationError(String error) {
        showProgress(false);
        userRegistration = null;
        Toast.makeText(getApplicationContext(), error,
                Toast.LENGTH_LONG).show();
    }
}

UserRegistration.java

package com.ocelotty.memestream.Services.Api;

import android.app.Activity;
import android.util.Log;

import com.android.volley.toolbox.JsonObjectRequest;
import com.ocelotty.memestream.MainActivity;
import com.ocelotty.memestream.Services.Api.Delegators.UserRegistrationDelegator;
import com.ocelotty.memestream.Services.ApiRequest;

import org.json.JSONException;
import org.json.JSONObject;
import com.ocelotty.memestream.Models.User;

/* Allows user registration. Returns QueueRequest to handle
 *
 * Example usage:
 * UserRegistration userRegistration = new UserRegistration("foo@bar.com", "pass", "pass");
 *
 * ApplicationController.getInstance().addToRequestQueue(userRegistration.call(this));
 * this - Activity (implements UserRegistrationDelegator)
 */
public class UserRegistration<T extends UserRegistrationDelegator> extends ApiRequest {
    public static class UnmatchedPasswordsException extends Exception {
        public UnmatchedPasswordsException(String s) {
            super(s);
        }
    }

    public String email, password, passwordConfirmation;

    private User user = null;

    public JsonObjectRequest request;

    /*
     * @param [String] email
     * @param [String] password
     * @param [String] passwordConfirmation
     *
     * Throws UnmatchedPasswordsException if password does not match confirmation
     */
    public UserRegistration(String email, String password, String passwordConfirmation) throws UnmatchedPasswordsException {
        this.email                = email;
        this.password             = password;
        this.passwordConfirmation = passwordConfirmation;

        checkPasswords();
    }

    public JsonObjectRequest call(T activity) {
        this.activity = activity;

        return postRequest(userParams(), "/users.json");
    }

    private void checkPasswords() throws UnmatchedPasswordsException {
        if (!password.equals(passwordConfirmation)) {
            Log.d("UserRegistration", "Passwords did not match");

            throw new UnmatchedPasswordsException("MEME_STREAM_PASSWORD_UNMATCHED");
        }
    }

    protected JSONObject userParams() {
        JSONObject user_params = new JSONObject();

        // Temp variable
        JSONObject payload = new JSONObject();

        try {
            payload.put("email", email);
            payload.put("password", password);
            payload.put("password_confirmation", passwordConfirmation);

            user_params.put("user", payload);
        }  catch (JSONException e) {
            e.printStackTrace();
        }

        return user_params;
    }

    protected void handleRequest(JSONObject response) {
        long   id    = 0;
        String email = null;

        try {
            id = response.getLong("id");
            email = response.getString("email");
        } catch (JSONException e) {
            e.printStackTrace();
        }

        User user = new User(id, email);

        T registrationActivity = (T) activity;
        registrationActivity.onUserRegistered(user);
    }

    protected void handleErrorRequest(String response) {
        T registrationActivity = (T) activity;
        registrationActivity.onUserRegistrationError(response);
    }
}

UserRegistrationDelegator.java

package com.ocelotty.memestream.Services.Api.Delegators;

import com.ocelotty.memestream.Models.User;

/**
 * Created by koleksiuk on 06/01/14.
 */
public interface UserRegistrationDelegator {
    void onUserRegistered(User user);
    void onUserRegistrationError(String response);
}