set text in label during an action event [duplicate]

Answer 1

There must be a delay between the setting of "Processing" and "Processed" JLabel text otherwise the change in text will be too quick to observe.

One way to do this is to use a Swing Timer between the 2 setText calls. Your JButton ActionListener could look like this:

public void actionPerformed(ActionEvent e) {
    label.setText("Processing...");

    ActionListener taskPerformer = new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            label.setText("Processed");
        }
    };
    Timer timer = new Timer(1000, taskPerformer); // delay one sec
    timer.setRepeats(false);
    timer.start();
}