back button alert box(Android Studio)

Question

In my first class, I have this piece of code:

public void onBackPressed() {
        new AlertDialog.Builder(this)
                .setIcon(R.drawable.ic_launcher)
                .setTitle(R.string.ALERTA1)
                .setMessage(R.string.ALERTA2)
                .setPositiveButton(R.string.ALERTA3, new DialogInterface.OnClickListener()
                {
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                })
                .setNegativeButton(R.string.ALERTA4, null)
                .show();
    }

This will make an alert box when the back button is pressed, but this works in every class, I only want it to work in this one.

UPDATE:

public void onBackPressed() {
    finish();
}

In every class.

Answer 1

Put this in your other classes:

public void onBackPressed() {
    super.onBackPressed();
    return;
}

That might work.