Is there any way to accept only numeric values in a JTextField?

Question

Is there any way to accept only numeric values in a JTextField? Is there any special method for this?

Answer 1

A simple approach is to subclass JTextField and override createDefaultModel() by returning customised PlainDocument subclass. Example - a textfield for integers only:

public class NumberField extends JTextField {


@Override
protected Document createDefaultModel() {
    return new Numberdocument();
}

class Numberdocument extends PlainDocument
{
    String numbers="1234567890-";
    @Override
    public void insertString(int offs, String str, AttributeSet a)
            throws BadLocationException {
        if(!numbers.contains(str));
        else    super.insertString(offs, str, a);
    }
}

Process input in insertString() any way.