Thread.Sleep() is freezing

Question

Here is a snippet

kit.insertHTML(doc, doc.getLength(), \"Hello\", 0, 0, null);
try{
Thread.sleep(1000);
}catch(Exception e){}

I am using

Answer 1

You are calling sleep on the EDT (Event Dispatching Thread). You should avoid this situation as indeed, it freezes the UI.

To avoid this situation, use a SwingWorker instead or as suggested by HFOE, use a Swing Timer