import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
private void logException(Throwable t, boolean isCause) {
  String msg = t.toString();
  if (isCause) {
    msg = "caused by: " + msg;
  }
  groupStart(msg);
  log(t);
  if (t instanceof UmbrellaException) {
    UmbrellaException umbrella = (UmbrellaException) t;
    for (Throwable cause : umbrella.getCauses()) {
      logException(cause, true);
    }
  } else if (t.getCause() != null) {
    logException(t.getCause(), true);
  }
  groupEnd();
}
 

import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
private static void log( @Nonnull final Throwable t, final boolean isCause )
{
  final String msg = ( isCause ? "caused by: " : "" ) + t;
  _groupStart( msg );
  _log( t );
  if ( t instanceof UmbrellaException )
  {
    final UmbrellaException umbrella = (UmbrellaException) t;
    for ( final Throwable cause : umbrella.getCauses() )
    {
      log( cause, true );
    }
  }
  else if ( null != t.getCause() )
  {
    log( t.getCause(), true );
  }
  _groupEnd();
}
 

import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
private static Throwable unwrap(Throwable e) {
    if (e instanceof UmbrellaException) {
        UmbrellaException ue = (UmbrellaException) e;
        if (ue.getCauses().size() == 1)
            return unwrap(ue.getCauses().iterator().next());
    }
    return e;
}
 

import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
@Override
public void onUncaughtException(Throwable e) {
	GWT.log("Unexpected exception", e);
	
	if(e instanceof UmbrellaException) {
		UmbrellaException umbrellaException = (UmbrellaException)e;
		if(umbrellaException.getCause() != null) {
			e = umbrellaException.getCause();
		}
		if(umbrellaException.getCauses() != null) {
			for(Throwable cause : umbrellaException.getCauses()) {
				if(cause instanceof StatusCodeException) {
					e = cause;
					break;
				}
			}
		}
	}
	
	if(e instanceof StatusCodeException) {
		StatusCodeException statusCodeException = (StatusCodeException)e;
		if(statusCodeException.getStatusCode() == 401 
				|| statusCodeException.getStatusCode() == 403) {
			errorLabel.setText("Unauthorized");
		} else {
			errorLabel.setText("HTTP status error: " + statusCodeException.getStatusCode());
		}
	} else {
		errorLabel.setText(e.getMessage());
	}
	dialogBox.center();
}
 

import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
public static Throwable unwrapUmbrellaException(Throwable e) {
    if (e instanceof UmbrellaException) {
        UmbrellaException ue = (UmbrellaException) e;
        if (ue.getCauses().size() == 1) {
            return unwrapUmbrellaException(ue.getCauses().iterator().next());
        }
    }
    return e;
}
 

import com.google.web.bindery.event.shared.UmbrellaException; //导入依赖的package包/类
@Override
public void run() {

    /* Add handlers, setup activities */
    GWT.setUncaughtExceptionHandler(new GWT.UncaughtExceptionHandler() {

        @Override
        public void onUncaughtException(Throwable e) {

            /* open the umbrella if it's an umbrella */
            e = unwrapException(e);

            e.printStackTrace();
            LOG.log(Level.SEVERE, "Uncaught exception", e);
        }

        private static final int MAX_UNWRAPS = 10;

        private Throwable unwrapException(Throwable throwable) {

            Throwable result = throwable;
            int attempts = 0;

            while (attempts < MAX_UNWRAPS) {

                if (result instanceof UmbrellaException && ((UmbrellaException) result).getCauses().size() == 1) {
                    result = ((UmbrellaException) throwable).getCauses().iterator().next();
                } else if (result instanceof com.google.web.bindery.event.shared.UmbrellaException
                        && ((com.google.web.bindery.event.shared.UmbrellaException) result).getCauses().size() == 1) {
                    result = ((com.google.web.bindery.event.shared.UmbrellaException) throwable).getCauses()
                            .iterator().next();
                } else {
                    break;
                }

                attempts++;
            }
            return result;
        }
    });

    /* activity management */
    CachingActivityMapper cached = new CachingActivityMapper(mainActivityMapper);
    ActivityManager mainActivityManager = new ActivityManager(cached, eventBus);
    mainActivityManager.setDisplay(applicationActivity.getViewPanel());

    /* add a panel for the desktop to add to if it needs to */
    SimpleLayoutPanel sp = new SimpleLayoutPanel();
    RootLayoutPanel.get().add(sp);

    applicationActivity.start(sp, eventBus);
}