Пытаясь сделать заставку из jframe, не могу переключать изображения

Я пытаюсь создать рамку screesaver в java.swing, используя построитель GUI NetBeans. Изображения не будут отображаться, когда я устанавливаю цикл infinte, который циклически перемещается между ними. Изображения устанавливаются для отображения в jLabel через setIcon. Вот код ниже:

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;


public class AdFrame extends javax.swing.JFrame {

    /**
     * Creates new form FifthFrame
     */
    public AdFrame() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        getContentPane().setLayout(new java.awt.GridBagLayout());

        jPanel1.setOpaque(false);

        jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/btc_gui/newpackage/btc-zg.jpg"))); // NOI18N

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(30, 30, 30)
                .addComponent(jLabel1)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(41, 41, 41)
                .addComponent(jLabel1)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        getContentPane().add(jPanel1, new java.awt.GridBagConstraints());

        pack();
    }// </editor-fold>                        

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(AdFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(AdFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(AdFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(AdFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                AdFrame ff1 = new AdFrame();
                ff1.setExtendedState(JFrame.MAXIMIZED_BOTH);
                ff1.setVisible(true);
                int index = 0;
                String[] filearray = new String[2];
                filearray[0] = "/btc_gui/newpackage/btc-zg.jpg";
                filearray[1] = "/btc_gui/newpackage/pic2.jpeg";
                while (true){
                    ff1.jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource(filearray[index])));
                    ff1.jLabel1.repaint();
                        try {
                            Thread.sleep(5000);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(AdFrame.class.getName()).log(Level.SEVERE, null, ex);
                        }
                    index++;
                    if (index >= filearray.length) index = 0;
                }
            }

        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JPanel jPanel1;
    // End of variables declaration                   
}