// WebAPIHelper Class

public class WebAPIHelper {
    private PopupWindow popupWindow;

    public boolean isProgressVisible = false;

    int requestNumber;
    LayoutInflater layoutInflater;
    LogInFragment logInFragment;

    public WebAPIHelper(int requestNumber, LogInFragment logInFragment, boolean isProgressVisible) {
        this.requestNumber = requestNumber;
        this.logInFragment = logInFragment;
        this.isProgressVisible = isProgressVisible;
        layoutInflater = (LayoutInflater) logInFragment.getActivity()
                .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    }

    public void callRequest(final String url) {

        String final_url = Constant.BasicUrl + url.replace(" ", "%20");
        System.out.println(final_url);
        new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                showProgDialog();
            }
        }, 100);

        StringRequest stringRequest = new StringRequest(Method.GET, final_url, new Response.Listener<String>() {

            @Override
            public void onResponse(String response) {
                try {
                    if (requestNumber == Constant.LOGIN) {

                        TestData data = new TestData();

                        JSONObject jsonObject = new JSONObject(response);

                        data.status = jsonObject.getString("status");
                        data.msg = jsonObject.getString("msg");

                        if (jsonObject.getString("status").equals("1")) {

                            JSONObject jObjData = jsonObject.getJSONObject("data");

                            data.user_id = jObjData.getString("user_id");
                            data.username = jObjData.getString("username");
                            data.email = jObjData.getString("email");
                        }

                        logInFragment.setResponse(requestNumber, data);
                    }
                    dissmissDialog();
                } catch (Exception e) {
                    System.out.println("catch :" + e.toString());
                } finally {
                    dissmissDialog();
                }
            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                // TODO Auto-generated method stub
                VolleyLog.d("volly error:", error.getMessage());

                dissmissDialog();
            }
        });

        MyApplication.getInstance().addToRequestQueue(stringRequest, "MYTestApp");
    }

    @SuppressLint("InflateParams")
    public void showProgDialog() {
        if (isProgressVisible) {
            try {
                View popupView = layoutInflater.inflate(R.layout.dialog_progress, null);
                popupWindow = new PopupWindow(popupView, RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
                popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);
                popupView.setOnClickListener(new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        // dissmissDialog();
                    }
                });
            } catch (Exception e) {
            }
        }
    }

    public void dissmissDialog() {
        try {
            if (popupWindow != null) {
                if (popupWindow.isShowing())
                    popupWindow.dismiss();
                popupWindow = null;
            }
        } catch (Exception e) {
            popupWindow = null;
        }
    }
}

// MyApplication Class

public class MyApplication extends Application {

	public MyApplication() {
		super();
	}

	public static final String TAG = "MYTestApp";

	private RequestQueue mRequestQueue;

	private static MyApplication mInstance;

	@Override
	public void onCreate() {
		super.onCreate();
		mInstance = this;
	}

    @Override
    protected void attachBaseContext(Context base) {
		// Multidex support install
        MultiDex.install(base);
        super.attachBaseContext(base);
    }

	public static synchronized MyApplication getInstance() {
		return mInstance;
	}

	public RequestQueue getRequestQueue() {
		if (mRequestQueue == null) {
			mRequestQueue = Volley.newRequestQueue(getApplicationContext());
		}
		return mRequestQueue;
	}

	public <T> void addToRequestQueue(Request<T> req, String tag) {
		req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
		getRequestQueue().add(req);
	}

	public <T> void addToRequestQueue(Request<T> req) {
		req.setTag(TAG);
		getRequestQueue().add(req);
	}

	public void cancelAllRequests(Object tag) {
		if (mRequestQueue != null) {
			mRequestQueue.cancelAll(tag);
		}
	}
}

// Constant class is just simple class

public class Constant {
    public static int LOGIN = 5001;
	
	// Show snackbar anywhere you want using Constant.showMsg(context, msg);
    public static void showMsg(Context context, String msg) {

        Snackbar snackbar = Snackbar.make(((Activity) context).findViewById(android.R.id.content), msg, Snackbar.LENGTH_LONG);
        View view = snackbar.getView();
        TextView tv = (TextView) view.findViewById(android.support.design.R.id.snackbar_text);
        tv.setBackgroundColor(ContextCompat.getColor(context, R.color.transparent));
        tv.setTextColor(Color.WHITE);

        snackbar.show();
    }
}

// How to use WebAPIHelper

WebAPIHelper webhelper = new WebAPIHelper(Constant.LOGIN, LogInFragment.this, true);
webhelper.callRequest("your url and get parameters");