Java restrict jtextfield textfield only accept numbers

textField.addKeyListener(new KeyAdapter() {
    public void keyPressed(KeyEvent key) {
        String value = textField.getText();
        int l = value.length();
        if (key.getKeyChar() >= '0' && key.getKeyChar() <= '9'|| key.getKeyCode()==KeyEvent.VK_BACK_SPACE) {
           textField.setEditable(true);
           label.setText("");
        } else {
           textField.setEditable(false);
           label.setText("* Enter only numeric digits(0-9)");
        }
    }
});