Jlabel rolante

/**
 * 
 */
package guj;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.Timer;

/**
 * Um marquee bem simples. Ele não implementa, por exemplo, o "width"
 */
public class SimpleMarquee extends JLabel {

    public SimpleMarquee() {
        super();
        setup ();
    }

    public SimpleMarquee(Icon image, int horizontalAlignment) {
        super(image, horizontalAlignment);
        setup ();
    }

    public SimpleMarquee(Icon image) {
        super(image);
        setup ();
    }

    public SimpleMarquee(String text, Icon icon, int horizontalAlignment) {
        super(text, icon, horizontalAlignment);
        setup ();
    }

    public SimpleMarquee(String text, int horizontalAlignment) {
        super(text, horizontalAlignment);
        setup ();
    }

    public SimpleMarquee(String text) {
        super(text);
        setup ();
    }
    
    private void setup () {
        timer = new Timer (0, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String text = getText();
                if (text != null && text.length() > 1) {
                    setText (text.substring(1) + text.charAt(0));
                }
            }
        });
        timer.setRepeats(true);
        timer.setDelay(period);
        timer.start();
    }

    public int getPeriod () {
        return timer.getDelay();
    }
    
    public void setPeriod (int period) {
        this.period = period;
        timer.setDelay (this.period);
    }
    
    private static final int defaultPeriod = 200;
    private int period = defaultPeriod;
    private Timer timer;
}

package guj;

import java.awt.BorderLayout;

public class ExemploSimpleMarquee extends JFrame {

    private static final long serialVersionUID = -4870168988827281628L;
    private JPanel contentPane;
    private SimpleMarquee lblTextoMuitoLongo;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    ExemploSimpleMarquee frame = new ExemploSimpleMarquee();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public ExemploSimpleMarquee() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);
        contentPane.add(getLblTextoMuitoLongo(), BorderLayout.NORTH);
    }

    private SimpleMarquee getLblTextoMuitoLongo() {
        if (lblTextoMuitoLongo == null) {
            lblTextoMuitoLongo = new SimpleMarquee("Texto muito longo, que deve ser mostrado como um marquee");
        }
        return lblTextoMuitoLongo;
    }
}