How to create a single .exe file?

Processing
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i tried a simple example in eclipse

package packageName;

import java.awt.FlowLayout;
import javax.swing.*;
	public class main {
	    public static void className(String s[]) {
               JFrame frame = new JFrame("JFrame Example");
	        JPanel panel = new JPanel();
	        panel.setLayout(new FlowLayout());
	        JLabel label = new JLabel("This is a label!");
	        JButton button = new JButton();
	        button.setText("Press me");
	        panel.add(label);
	        panel.add(button);
	        frame.add(panel);
	        frame.setSize(300, 300);
	        frame.setLocationRelativeTo(null);
	        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	        frame.setVisible(true);
	    }
	}

then
file > export > Java > Runnable JAR File > next > select launch configuration > select export destination > finish
i now have a runnable jar file
PNG