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.

Answer 2

A quick solution:

JTextField textField = new JTextField() {
  public void processKeyEvent(KeyEvent ev) {
    char c = ev.getKeyChar();
    if (c >= 48 && c <= 57) { // c = '0' ... c = '9'
      super.processKeyEvent(ev);
    }
  }
};

The problem with the above solution is that the user cannot use the Delete, Left Arrow, Right Arrow, or Backspace keys in the text field, so I suggest using this solution:

this.portTextField = new JTextField() {
  public void processKeyEvent(KeyEvent ev) {
    char c = ev.getKeyChar();
    try {
      // Ignore all non-printable characters. Just check the printable ones.
      if (c > 31 && c < 127) {
        Integer.parseInt(c + "");
      }
      super.processKeyEvent(ev);
    }
    catch (NumberFormatException nfe) {
      // Do nothing. Character inputted is not a number, so ignore it.
    }
  }
};

Answer 3

Look at JFormattedTextField.

Answer 4

You can create a beautiful text field in java that accepts or allows only numeric values.. You can even set the precision for the float values... check the code in zybocodes

Answer 5

numberField = new JFormattedTextField(NumberFormat.getInstance());

Formatted text field tutorial

Answer 6

I think it is the best solution:

JTextField textField = new JFormattedTextField(new MaskFormatter("###")); //