how add a listener for jtexfield when it changing?

Question

I have a JTextField. I want to invoke a function when the text in it is changed.

How do I do that?

Answer 1

The appropriate listener in Java's swing to track changes in the text content of a JTextField is a DocumentListener, that you have to add to the document of the JTextField:

myTextField.getDocument().addDocumentListener(new DocumentListener() {
    // implement the methods
});

Answer 2

Use Key Listener in this way

JTextField tf=new JTextField();
tf.addKeyListener(new KeyAdapter()
    {
        public void keyPressed(KeyEvent ke)
        {
            if(!(ke.getKeyChar()==27||ke.getKeyChar()==65535))//this section will execute only when user is editing the JTextField
            {
                System.out.println("User is editing something in TextField");
            }
        }
    });

Answer 3

You can use Caret Listener

        JTextField textField = new JTextField();
    textField.addCaretListener(new CaretListener() {

        @Override
        public void caretUpdate(CaretEvent e) {
            System.out.println("text field have changed");

        }
    });

Answer 4

You can add a KeyListener or a ActionListener to the field and capture events.