Нужно сделать исполняемый jar.

import java.awt.*; 
import javax.swing.*; 
import javax.swing.border.*; 
import javax.swing.plaf.metal.*; 
 
 
public class Metalworks { 
 
    public static void main( String[] args ) { 
        JDialog.setDefaultLookAndFeelDecorated(true); 
        JFrame.setDefaultLookAndFeelDecorated(true); 
        Toolkit.getDefaultToolkit().setDynamicLayout(true); 
        System.setProperty('sun.awt.noerasebackground','true'); 
 
        try { 
            javax.swing.plaf.metal.MetalLookAndFeel.setCurrentTheme( new javax.swing.plaf.metal.DefaultMetalTheme()); 
            UIManager.setLookAndFeel('javax.swing.plaf.metal.MetalLookAndFeel'); 
        }   
        catch ( UnsupportedLookAndFeelException e ) { 
            System.out.println ('Metal Look & Feel not supported on this platform. 
Program Terminated'); 
            System.exit(0); 
        } 
        catch ( IllegalAccessException e ) { 
            System.out.println ('Metal Look & Feel could not be accessed. 
Program Terminated'); 
            System.exit(0); 
        } 
        catch ( ClassNotFoundException e ) { 
            System.out.println ('Metal Look & Feel could not found. 
Program Terminated'); 
            System.exit(0); 
        }    
        catch ( InstantiationException e ) { 
            System.out.println ('Metal Look & Feel could not be instantiated. 
Program Terminated'); 
            System.exit(0); 
        } 
        catch ( Exception e ) { 
            System.out.println ('Unexpected error. 
Program Terminated'); 
            e.printStackTrace(); 
            System.exit(0); 
        } 
        JFrame frame = new MetalworksFrame(); 
        frame.setVisible(true); 
    } 
}

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.plaf.metal.*;
 
public class Metalworks {
 
    public Metalworks() {
 
        JDialog.setDefaultLookAndFeelDecorated(true);
        JFrame.setDefaultLookAndFeelDecorated(true);
        Toolkit.getDefaultToolkit().setDynamicLayout(true);
        System.setProperty('sun.awt.noerasebackground','true');
 
        try {
            javax.swing.plaf.metal.MetalLookAndFeel.setCurrentTheme( new javax.swing.plaf.metal.DefaultMetalTheme());
            UIManager.setLookAndFeel('javax.swing.plaf.metal.MetalLookAndFeel');
        }  
        catch ( UnsupportedLookAndFeelException e ) {
            System.out.println ('Metal Look & Feel not supported on this platform. 
Program Terminated');
            System.exit(0);
        }
        catch ( IllegalAccessException e ) {
            System.out.println ('Metal Look & Feel could not be accessed. 
Program Terminated');
            System.exit(0);
        }
        catch ( ClassNotFoundException e ) {
            System.out.println ('Metal Look & Feel could not found. 
Program Terminated');
            System.exit(0);
        }   
        catch ( InstantiationException e ) {
            System.out.println ('Metal Look & Feel could not be instantiated. 
Program Terminated');
            System.exit(0);
        }
        catch ( Exception e ) {
            System.out.println ('Unexpected error. 
Program Terminated');
            e.printStackTrace();
            System.exit(0);
        }
        JFrame frame = new MetalworksFrame();
        frame.setContentPane(new NestedLayout());
        frame.pack();
        frame.setVisible(true);
  
    }
    public static void main( String[] args ) {
    new Metalworks();
    }
}