Question

I have a small image processing application which does multiple things at once using SwingWorker. However, if I run the following code (oversimplified excerpt), it just hangs on JDK 7 b70 (windows) but works in 6u16. It starts a new worker within another worker and waits for its result (the real app runs multiple sub-workers and waits for all this way). Did I use some wrong patterns here (as mostly there is 3-5 workers in the swingworker-pool, which has limit of 10 I think)?

import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;

public class Swing {
       static SwingWorker<String, Void> getWorker2() {
               return new SwingWorker<String, Void>() {
                       @Override
                       protected String doInBackground() throws Exception {
                               return "Hello World";
                       }
               };
       }
       static void runWorker() {
               SwingWorker<String, Void> worker 
                   = new SwingWorker<String, Void>() {
                       @Override
                       protected String doInBackground() throws Exception {
                               SwingWorker<String, Void> sw2 = getWorker2();
                               sw2.execute();
                               return sw2.get();
                       }
               };
               worker.execute();
               try {
                       System.out.println(worker.get());
               } catch (Exception e) {
                       e.printStackTrace();
               }
       }
       public static void main(String[] args) {
               SwingUtilities.invokeLater(new Runnable() {
                       @Override
                       public void run() {
                               runWorker();
                       }
               });
       }

}

Answer 1

As nobody has fired off the link yet, it seems this is actually a known bug:

https://bugs.java.com/bugdatabase/view_bug?bug_id=6880336

Surprisingly there are less than 100 votes for what should be a showstopper bug for most non-trivial applications.