Java Swing multithreading and UI freezing

I can't think of this Using worker or invoker, the UI will still freeze After downloading each file, I want to update JList However, JList will only be updated after the tread returns

This is the code:

public class MyUi extends javax.swing.JFrame{
    ...

   private void jButton2ActionPerformed(java.awt.event.ActionEvent evt){

      SwingUtilities.invokelater(new Runnable() {
         //To get out of the event tread
         public void run() {
            dl(); 
         }
       });
   }

   private void dl(){
      ...
      //ini and run the download class
      Download myDownload = new Download();
      myDownload.doDownload(myDlList);
   }

   public void updateJlist(String myString){

       myModel.addElement(myString);
       jList1.repaint();
   }

}

public class Download{
...

  public void doDownload(String[] fileName){
      for(int i=0; i<fileName.length; i++){
         ...//download action...
         //for my jList1 to be updated after each file.
         MyUi.updateJlist(fileName[i]);
      }
   }

}

Any example will help

Solution

Download the file on the background thread and wrap updatejlist () in runnable

Swingworker will be more reliable

Appendix: as @mre said, swing worker can also easily report interim results, as shown here