How to use : Java GUI SwingWorker and JProgressBar

public class MyForm extends JFrame {

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MyForm form = new MyForm();
				form.setVisible(true);
			}
		});
	}

	public MyForm() {
		new BackgroundWorker().execute();
	}
	
	public class BackgroundWorker extends SwingWorker<Void, Void> {

		public BackgroundWorker() {

			});
		}

		@Override
		protected void done() {

		}

		protected Void doInBackground() throws Exception {
			/**
			 *  Do work
			 *  Do work
			 *  Do work
			 */
		}	
	}
}

package com.java.myapp;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;

public class MyForm extends JFrame {
	private JProgressBar progressBar;
	private JButton btnStart;

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MyForm form = new MyForm();
				form.setVisible(true);
			}
		});
	}

	public MyForm() {

		// Create Form Frame
		super("ThaiCreate.Com Java GUI Tutorial");
		setSize(525, 270);
		setLocation(500, 280);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		getContentPane().setLayout(null);

		// Label Title
		final JLabel lblTitle = new JLabel("ProgressBar", JLabel.CENTER);
		lblTitle.setBounds(73, 24, 370, 14);
		getContentPane().add(lblTitle);
		
		// ProgressBar
		progressBar = new JProgressBar();
		progressBar.setStringPainted(true);
		progressBar.setMinimum(0);
		progressBar.setMaximum(100);
		progressBar.setBounds(163, 80, 190, 20);
		getContentPane().add(progressBar);


		// Button Start
		btnStart = new JButton("Start");
		btnStart.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				btnStart.setEnabled(false);
				EventQueue.invokeLater(new Runnable() {
					@Override
					public void run() {
						new BackgroundWorker().execute();
					}
				});
	
			}
		});
		btnStart.setBounds(209, 144, 100, 23);
		getContentPane().add(btnStart);
		
	}
	
	public class BackgroundWorker extends SwingWorker<Void, Void> {

		public BackgroundWorker() {
			addPropertyChangeListener(new PropertyChangeListener() {
				@Override
				public void propertyChange(PropertyChangeEvent evt) {
					progressBar.setValue(getProgress());
				}

			});
		}

		@Override
		protected void done() {
			btnStart.setEnabled(true);
		}

		protected Void doInBackground() throws Exception {
			for (int index = 0; index <= 100; index++) {
				setProgress(index);
				Thread.sleep(100);
				/**
				 *  Do work
				 *  Do work
				 *  Do work
				 */
			}
			return null;
		}
		
	}
	
}

protected Void doInBackground() throws Exception {
	for (int index = 0; index <= 100; index++) {
		setProgress(index);
		Thread.sleep(100);
		/**
		 *  Do work
		 *  Do work
		 *  Do work
		 */
	}
	return null;
}