My MessageBox (AlertDialog) is not working as expected

[Naziru Gelajo]

I don't seem to get why it's not working. It is checking the EditText (TextBoxes) to check and see if the input is empty (empty string literal is defined as ""). When I leave all text boxes empty in the app, and click the button, it is supposed to display this AlertDialog. Instead, the app crashes. Any suggestions on what I am doing wrong? Thanks!

 public void calculateMonthlyPayment(View view) {

        if (interest.getText().equals("") || price.getText().equals("") || dwnPymnt.getText().equals("")
                || numYears.getText().equals("")) {
            /*
            Check if any of the input fields is blank during the tapping button process
             */
            AlertDialog.Builder warningMessage = new AlertDialog.Builder(MainActivity.this);
            warningMessage.setMessage("Please make sure that no input fields are empty!")
                .setCancelable(false)
                .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });
            AlertDialog warningAlert = warningMessage.create();
            warningAlert.setTitle("Empty Field(s)");
            warningAlert.show();
        }
 }

[Knute Snortum]

When you say, "The app crashes," what exactly happens?  Error message?  App is unresponsive?  Please TellTheDetails (that's a link).

[Knute Snortum]

        if (interest.getText().equals("") || price.getText().equals("") || dwnPymnt.getText().equals("")
                || numYears.getText().equals("")) {

A better way to do this is...

        if (interest.getText().isEmpty() || ...