Revised MainActivity

 Button PostButton, GetButton;
    TextView UsernameTextView, PasswordTextView;
    EditText UsernameEditText, PasswordEditText;
   // 192.168.1.210

    // static fields
    private static String URL = "http://192.168.1.210/cpsscripts/total_items.php";
    private static String GET_TOTAL = "gettotal";


    // objetcs
    JSONParser jsonParser ;
    List<NameValuePair> params;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Views Import
       PostButton = (Button) findViewById(R.id.post_button);
        GetButton = (Button) findViewById(R.id.get_button);
        UsernameEditText = (EditText) findViewById(R.id.username_edittext);
        PasswordEditText = (EditText) findViewById(R.id.password_edittext);
        UsernameTextView = (TextView) findViewById(R.id.username_textView);
        PasswordTextView = (TextView) findViewById(R.id.password_textView);


        // Objects
//          jsonParser = new JSONParser();
//          params = new ArrayList<NameValuePair>();
//
//
//          params.add(new BasicNameValuePair("", ""));


            PostButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    new GetTotal().execute();

//                  try {
//                      JSONObject json = jsonParser.getJSONFromURL(URL, params);
//                      String res = json.getString("gettotal");
//                      UsernameTextView.setText(res);
//                  } catch (JSONException e) {
//                      e.printStackTrace();
//                  }
                }
            });


     }

        private class GetTotal extends AsyncTask<Void, Void, String>{

            @Override
            protected String doInBackground(Void... args) {
                // TODO Auto-generated method stub
                jsonParser = new JSONParser();
                params = new ArrayList<NameValuePair>();


                params.add(new BasicNameValuePair("", ""));

                try {
                    JSONObject json = jsonParser.getJSONFromURL(URL, params);
                    String res = json.getString("gettotal");
                    //UsernameTextView.setText(res);
                    System.out.println("Res: " + res);
                    return res;
                } catch (JSONException e) {
                    e.printStackTrace();
                }

                return null;
            }

            @Override
            protected void onPostExecute(String result) {
                // TODO Auto-generated method stub
                super.onPostExecute(result);
                UsernameTextView.setText(result);
            }

        }

}