Text Changed event in JTextArea? How to?

Question

I have been trying to make a text changed event handling mechanism for my JTextArea. For my purposes an event has to be fired whenever there is a change in the

Answer 1

Not the JTextArea, but the contained document receives updates, so you need:

jTextArea.getDocument().addDocumentListener(new DocumentListener() {

        @Override
        public void removeUpdate(DocumentEvent e) {

        }

        @Override
        public void insertUpdate(DocumentEvent e) {

        }

        @Override
        public void changedUpdate(DocumentEvent arg0) {

        }
    });

Answer 2

You are comparing strings with ==

if (currentText == textString)

This will never be true. This compares if the strings are the same String object. You should use equals.

if (currentText.equals( textString) )

You might also want to check out DocumentListeners. See also this How do I compare strings in Java?

Answer 3

I would get the JTextArea's Document via getDocument() (a PlainDocument actually) and use a DocumentListener to listen for changes. This way you'd capture changes from key strokes and also from copy/paste/cut events.