JTextField limiting character amount input and accepting numeric only

Question

here\'s the code that i have on how to limit the character input length

class JTextFieldLimit extends PlainDocument {
  private int limit;
  // optional uppe         


        

Answer 1

yourJTextField.addKeyListener(new KeyAdapter()
        {
            @Override
            public void keyTyped(KeyEvent e)
            {
                // Here limiting the character of your number. for examlpe this wil only accept one digit
                if (yourJTextField.getText().length() == 1) {
                    e.consume();
                }

                // Here limiting your input to only number
                char c = e.getKeyChar();
                if(!((c >= '0') && (c <= '7') || (c == KeyEvent.VK_BACK_SPACE) || (c == KeyEvent.VK_DELETE)))
                {
                    //do what so ever you want
                }
                else
                {
                    //do what so ever you want
                }
            }
        })