Why is my Runnable Jar file not working

Question

I followed about 10 different tutorials and none of them seemed to do the trick, my runnable jar file just isn't working.

My game runs fine when I run it in eclipse, and I was able to make it into a runnable jar file that worked only a day or two ago and have not changed too much code. When I try to run the .jar a java icon pops up at the bottom of my screen but then nothing happens.

It's my launcher is failing to open (if I run without launcher it works fine), there are no errors wether I open with terminal or eclipse.

package com.l3g3nds.threed;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.io.File;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

public class Launcher extends JFrame implements MouseListener, MouseMotionListener {
    private static final long serialVersionUID = 1L;

    protected JPanel window = new JPanel();
    // private JButton play, options, help, quit, credits;
    // private Rectangle rplay, roptions, rhelp, rquit, rcredits;

    protected int buttonWidth = 120;
    protected int buttonHeight = 40;

    public Launcher(int id) {
        JPanel panel = (JPanel) getContentPane();

        JLabel label = new JLabel();
        label.setIcon(new ImageIcon("res/Launcher/schoolbackground.png"));
        System.out.println(Display.lScreen());
        if (Display.lScreen() == 5)
            label.setIcon(new ImageIcon("res/Launcher/quit1.png"));
        if (Display.lScreen() == 4)
            label.setIcon(new ImageIcon("res/Launcher/credits1.png"));
        if (Display.lScreen() == 3)
            label.setIcon(new ImageIcon("res/Launcher/options1.png"));
        if (Display.lScreen() == 2)
            label.setIcon(new ImageIcon("res/Launcher/help1.png"));
        if (Display.lScreen() == 1)
            label.setIcon(new ImageIcon("res/Launcher/beginrunning1.png"));
        panel.add(label);

        setUndecorated(true);

        System.out.println("launched");
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        setLocationRelativeTo(null);
        pack();
        setVisible(true);

        addMouseListener(this);
        addMouseMotionListener(this);

    }

    public void drawButtons() {
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        int cx = e.getX();
        int cy = e.getY();
        if (cx >= 11 && cy >= 14 && cx <= 214 && cy <= 44) {
            dispose();
            new RunGame();
        } else if (cx >= 11 && cy >= 66 && cx <= 70 && cy <= 96) {
            //open help
        } else if (cx >= 11 && cy >= 119 && cx <= 119 && cy <= 144) {
            this.dispose();
            new Options();
        } else if (cx >= 11 && cy >= 170 && cx <= 114 && cy <= 200) {
            //open credits
        } else if (cx >= 11 && cy >= 222 && cx <= 74 && cy <= 254) {
            System.exit(0);
        }

    }

    @Override
    public void mouseEntered(MouseEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mouseExited(MouseEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mousePressed(MouseEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mouseReleased(MouseEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mouseDragged(MouseEvent arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void mouseMoved(MouseEvent e) {
        // TODO Auto-generated method stub
        int mx = e.getX();
        int my = e.getY();
        if (mx >= 11 && my >= 14 && mx <= 214 && my <= 44) {
            if (Display.lScreen() != 1) {
                Display.setlScreen(1);
                new Launcher(1);
                System.out.println("1");
            }
        } else if (mx >= 11 && my >= 66 && mx <= 70 && my <= 96) {
            if (Display.lScreen() != 2) {
                Display.setlScreen(2);
                new Launcher(1);
                System.out.println("2");
            }
        } else if (mx >= 11 && my >= 119 && mx <= 119 && my <= 144) {
            if (Display.lScreen() != 3) {
                Display.setlScreen(3);
                new Launcher(1);
                System.out.println("3");
            }
        } else if (mx >= 11 && my >= 170 && mx <= 114 && my <= 200) {
            if (Display.lScreen() != 4) {
                Display.setlScreen(4);
                new Launcher(1);
                System.out.println("4");
            }
        } else if (mx >= 11 && my >= 222 && mx <= 74 && my <= 254) {
            if (Display.lScreen() != 5) {
                Display.setlScreen(5);
                new Launcher(1);
                System.out.println("5");
            }
        }
        else {
            if (Display.lScreen() != 0) {
                Display.setlScreen(0);
                new Launcher(1);
                System.out.println("0");
            }
        }
    }
}

I'm using a mac if that helps...

Here are screen shots that I took of the exact steps I took

Some warnings I got (I think they are only because of unused variables, I got this message earlier when I was able to get my .jar to work)

This appears that the top of my screen along with the java icon at the bottom, but nothing else happens.

-Thanks

Answer 1

I assume you're making a GUI application, and launching the Jar by clicking on it? Many times if a GUI application has an error at startup, it doesn't visibly do anything, like pop an error message, because it hasn't had a chance to build any sort of GUI to report the error to yet. I would guess that something you changed causes an exception at startup, and that message is not visible because you're launching the jar by clicking on it.

If you run the Jar from the terminal instead (spotlight: "terminal") you will be able to see the stack trace that's preventing your Jar from running, and hopefully that will help you debug further.

$ cd directory/of/jar
$ java -jar name_of_jar.jar
  .... stack trace should appear here, or program should run

---

You can also try to catch the exception in your main method and display a GUI alert, however this doesn't work if the exception is raised before the main method starts (e.g. during class loading). In other words it's a nice-to-have, but doesn't totally solve the problem. You may still need to run the Jar from the command line.

public static void main(String[] args) {
  try {
    // body of main method goes here, including any other error handling
  } catch (Throwable t) {
    JOptionPane.showMessageDialog(
        null, t.getClass().getSimpleName() + ": " + t.getMessage());
    throw t; // don't suppress Throwable
  }
}