Java JFrame Window not appearing when run from Eclipse

Question

A very simple problem. I try to run a very simple demo to created and display a Window Frame from Eclipse, and nothing happens. No errors, no window, the code runs to completion.

I added breakpoints and made sure the code runs as expected. The code is straight from Java tutorials (FrameDemo), I just renamed the package to fit where I placed it (other code from this package runs fine):

package ui;

import java.awt.*;
import javax.swing.*;

/* FrameDemo.java requires no other files. */
public class FrameDemo {
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("FrameDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel emptyLabel = new JLabel("");
        emptyLabel.setPreferredSize(new Dimension(175, 100));
        frame.getContentPane().add(emptyLabel, BorderLayout.CENTER);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

My setup (Kepler SR2):

• eclipse.buildId=4.3.2.M20140221-1700
• java.version=1.8.0_05
• java.vendor=Oracle Corporation
• BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
• Framework arguments: -product org.eclipse.epp.package.java.product -keyring /Users/steve/.eclipse_keyring -showlocation
• Command-line arguments: -os macosx -ws cocoa -arch x86_64 -product org.eclipse.epp.package.java.product -keyring /Users/steve/.eclipse_keyring -showlocation

I also checked Configuration -> error logs; still nothing, no errors. I tried other similar demos, same results.

Any help would be appreciated as I have been stuck on this for over a day.

Answer 1

macOS + Eclipse + swt.jar gives this issue.

Turns out, in macOS, Eclipse adds a special argument -XstartOnFirstThread when starting the GUI app if you have swt.jar in the classpath. After removing swt.jar from external libraries (used to build classpath), problem solved.

Answer 2

It turns out I had a library problem. I had had imported all the jars in the .lib directory from jfreechart. In reality only two were needed and some unnecessary ones were labeled swt and experimental. Once I removed all the ones that were not needed, did a clean, and rebuilt, everything worked fine.

Oddly, changing the order of the jfreechart library (which included the conflicting jars) to the bottom did not help, the extra jars had to be removed.

Not a jfreechart issue, obviously my own library import issue. If you run into this I suggest you try to remove some of the libraries that may be conflicting, then clean, build, and run again.

Thanks to Hovercraft Full Of Eels and everyone else who responded for helping me out.