Disable input some symbols to JTextField

Question

How can I disable input of any symbol except digits to JTextField?

Answer 1

For a better user experience

Others have mentioned the use of JFormattedTextField or KeyListeners to prevent invalid data from being entered but from a usability point of view I find it very annoying to start typing into a field and nothing happens.

To provide a better user experience you can allow the user to enter non-numeric values in the field but use a validator to provide feedback to the user and disable the submit button.