Does Java thread sleep puts swing ui to sleep

Question

I have the following code where I am trying to run a check at every hour interval on the selected directory(s) using thread.sleep() method through JFileChooser. But the issue is whenever I try to select the directory and execute the method, it puts the UI to sleep as well. Can someone help me out of this?

if (option == JFileChooser.APPROVE_OPTION) {
    selectedDirectory = chooser.getSelectedFiles();
    try {
        while (true) {
            runCheck(selectedDirectory);
            Thread.sleep(1000*5);//1000 is 1 second
        }
    } catch (InterruptedException e1) {
        Thread.currentThread().interrupt();
        e1.printStackTrace();
    }               
} 

Answer 1

Your thread.sleep() puts the UI to sleep because it is being invoked on the Event Dispatch Thread which is responsible for running the gui. Thus, the UI stops processing events and 'goes to sleep'.

To avoid this you can make use of javax.swing.Timer.

Timer t = new Timer(1000 * 5, new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        // do your reoccuring task
    }
});

This won't leave your UI unresponsive.

Answer 2

You are correct about the code putting the UI to sleep. Since sleep is called on the Event Dispatch Thread (the thread responsible for running the gui) the UI stops processing events and 'goes to sleep'.

Timer t = new Timer(1000 * 5, new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        // do your reoccuring task
    }
});

This will cause your reoccurring task to be performed off of the EDT, and thus it wont leave your ui unresponsive.