Volley Server request class

HttpCaller.java

/**
 * this class helps us to make http calls
 */

public class HttpCaller {

    private Context context;
    //private ProgressDialog pDialog;
    private HttpProgressDialog httpProgressDialog;

    public HttpCaller(Context context) {
        this.context = context;
    }

    // this is for POST method
    public void callServer(String URL,
                           final HashMap<String, String> params,
                           final HttpCaller.VolleyCallback callback) {

        if (!checkInternetConnection(context)) {
            showNoInternetDialogue(context);
            return;
        }

        httpProgressDialog = new HttpProgressDialog(context);
        httpProgressDialog.showDialog();

        RequestQueue requestQueue = Volley.newRequestQueue(context);
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URL, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                callback.onSuccess(response);
                httpProgressDialog.hideDialog();

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                callback.onError(volleyError.toString());
                showSMR(context, volleyError);
                httpProgressDialog.hideDialog();
            }
        }
        ) {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError{
                Log.e("serverParams", params.toString());
                return params;
            }

            @Override
            public Map<String, String> getHeaders() {
                return new HashMap<>();
            }

        };
        //setting up the retry policy for slower connections
        int socketTimeout = 120000;//120000 milli seconds - change to what you want
        RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        stringRequest.setRetryPolicy(policy);

        requestQueue.add(stringRequest);
    }


    public void getCaller(String URL, final HttpCaller.VolleyCallback callback) {
        if (!checkInternetConnection(context)) {
            showNoInternetDialogue(context);
            return;
        }

        httpProgressDialog = new HttpProgressDialog(context);
        httpProgressDialog.showDialog();

        RequestQueue requestQueue = Volley.newRequestQueue(context);
        StringRequest stringRequest = new StringRequest(Request.Method.GET, URL, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                callback.onSuccess(response);
                httpProgressDialog.hideDialog();

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                callback.onError(volleyError.toString());
                showSMR(context, volleyError);
                httpProgressDialog.hideDialog();
            }
        }
        ) {
            @Override
            protected Map<String, String> getParams() {
                return new HashMap<>();
            }

            @Override
            public Map<String, String> getHeaders() {
                Map<String, String> headers = new HashMap<>();
                headers.put("Content-Type", "application/x-www-form-urlencoded");
                return headers;
            }

        };
        //setting up the retry policy for slower connections
        int socketTimeout = 120000;//120000 milli seconds - change to what you want
        RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        stringRequest.setRetryPolicy(policy);

        requestQueue.add(stringRequest);
    }

    // interface for callback
    public interface VolleyCallback {
        void onSuccess(String result);
        void onError(String error);
    }

  

    private static boolean checkInternetConnection(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

    private static void showNoInternetDialogue(final Context context) {
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setCancelable(true);
        builder.setMessage("Please enable Internet");
        builder.setPositiveButton("WIFI SETTINGS", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                context.startActivity(new Intent(WifiManager.ACTION_PICK_WIFI_NETWORK));
            }
        });
        builder.setNegativeButton("MOBILE INTERNET", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                context.startActivity(new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS));
            }
        });
        builder.setTitle(R.string.app_name);
        AlertDialog dialog = builder.create();
        dialog.show();
    }
}

HttpProgressDialog.java

/**
 * this is for showing progress dialogue when user makes http call
 */

public class HttpProgressDialog {

    private Dialog dialog;
    private ProgressBar progressBar;

    public HttpProgressDialog(Context context) {
        dialog = new Dialog(context);
        dialog.setContentView(R.layout.progress_layout);
        dialog.setCancelable(false);
        if(dialog.getWindow() != null){
            dialog.getWindow()
                    .setLayout(ViewGroup.LayoutParams.MATCH_PARENT,
                            ViewGroup.LayoutParams.WRAP_CONTENT);
            dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
        }
        progressBar = (ProgressBar)dialog.findViewById(R.id.progressBar);
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                progressBar.getIndeterminateDrawable().setColorFilter(randomColor(), PorterDuff.Mode.MULTIPLY);
                new Handler().postDelayed(this, 300);
            }
        }, 0);

    }

   public void showDialog(){
        dialog.show();
    }

   public void hideDialog(){
        dialog.cancel();
    }

    // get random color
    private int randomColor(){
        int[] colors  = new int[]{
                Color.RED,
                Color.YELLOW,
                Color.WHITE,
                Color.GREEN,
                Color.BLUE
        };
        return colors[new Random().nextInt(4)];
    }
}