ExecutorService queue = Executors.newSingleThreadExecutor();
...
queue.submit(... boot actions ...);
queue.submit(... boot actions ...);
...
queue.submit(new Runnable() {
  public void run() {
    if (!EventQueue.isDispatchThread()) {
      EventQueue.invokeLater(Runnable.this);
      return;
    }
    .... // post-boot gui actions, e.g. setStatus("OK");
  }
});