Simulando uma porcentagem no JProgressBar e NetBeans

import java.awt.<em>;

import java.awt.event.</em>;

import java.util.*;

import javax.swing.<em>;

import javax.swing.Timer;

import javax.swing.event.</em>;

public class ProgressBar

{

public static void main(String[] args)

{

JFrame frame = new ProgressBarFrame();

frame.show();

}

}

class ProgressBarFrame extends JFrame

{

private Timer activitMonitor;

private JButton startButton;

private JTextArea textArea;

private JProgressBar progressBar;

private SimulatedActivity activity;

public ProgressBarFrame()
{
	setTitle("ProgressBar");
	setSize(300,200);
	addWindowListener(new WindowAdapter()
	{
		public void windowClosing(WindowEvent e)
		{
			System.exit(0);
		}
		
	});
	Container contentPane  = getContentPane();
    // esta área de texto contém o resultado gerado pela atividade
	textArea = new JTextArea();
	//configura o painel com botão e barra de progresso
	JPanel panel = new JPanel();
	startButton = new JButton();
	progressBar = new JProgressBar();
	
	panel.add(startButton);
	panel.add(progressBar);
	contentPane.add(new JScrollPane(textArea),"Center");
	contentPane.add(panel,"South");
	//configura a ação do botão
	startButton.addActionListener(new ActionListener()
	{
		public void actionPerformed(ActionEvent event)
		{
			progressBar.setMaximum(100);
			activity = new SimulatedActivity(1000);
			activity.start();
			activitMonitor.start();
			startButton.setEnabled(false);
		}
	});
	//configura a ação do temporizador
	activitMonitor = new Timer(500,new ActionListener()
	{
		public void actionPerformed(ActionEvent event)
		{
			int current = activity.getCurrent();
			//textArea.append(current + "\n");
			progressBar.setString("JESUS TE AMA");
			progressBar.setValue(current);
			
			if(current == activity.getTarget())
			{
				activitMonitor.stop();
				startButton.setEnabled(true);
			}
		}
	});

}

class SimulatedActivity extends Thread

{

private int current,target;

public SimulatedActivity(int t)

{

current = 0;

target = t;

}

public int getCurrent()

{

return current;	

}

public int getTarget()

{

return target;

}

public void run()

{

while(current < target && !interrupted())

{

try{

sleep(100);

}catch(InterruptedException e){

return;

}

current++;

}

}