How can I use the Class JpcapCaptor loopPacket method without blocking my Windows app

[Sam Picture]

If I use the Class JpcapCaptor processPacket method this application
gets a run-time "java.lang.NoSuchMethodError: setRoutingOption" error
and it closes, and no packets are captured or displayed. I would like
to be able to use this method because unlike the Class JpcapCaptor
loopPacket method it will not block the application's event dispatching
thread which is used by its graphical user interface and
prevent me from being able to interact with it to stop the capture
process, print the capture information, etc.

If I use the Class JpcapCaptor loopPacket method this application gets
a run-time "java.lang.NoSuchMethodError: setRoutingOption" error and it
continues, and packets are captured and displayed. However, as
previously mentioned this method blocks the application's event
dispatching thread which is used by its graphical user interface
which prevents me from being able to interact with it to stop the
capture process, print the capture information, etc.

Since I cannot use the Class JpcapCaptor processPacket method, I need to
find a way to use the Class JpcapCaptor loopPacket method that will not
block the application's event dispatching thread. One way might
be to have the method use a separate thread, for example a SwingWorker
worker thread. There are probably some other ways to do it, as well.
I am a beginning Java programmer and I do not understand how to do any
of them. I need help! I am visually oriented. Please include
example code, not just text explanations so that I can understand the
solution you propose.

import java.io.IOException;
import java.net.URL;
import java.text.MessageFormat;
 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Font;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.Toolkit;
 
import javax.swing.JButton;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JToolBar;
import javax.swing.SwingWorker;
 
import jpcap.*;
import jpcap.packet.Packet;
 
public class JpcapPacketCapture extends JFrame implements PacketReceiver
{
  JFrame frame;
  JTextArea textArea;
  JpcapCaptor jpcapCaptor;
  JpcapPacketCapture jpcapPacketCapture;
 
  int duration;
  int interfaceNo;
  int lineEndOffset;
 
  static URL url1 = JpcapPacketCapture.class.getResource("images/Start.gif");
  ImageIcon start = new ImageIcon(url1);
 
  static URL url2 = JpcapPacketCapture.class.getResource("images/Stop.gif");
  ImageIcon stop = new ImageIcon(url2);
 
  static URL url3 = JpcapPacketCapture.class.getResource("images/Clear.gif");
  static ImageIcon clear = new ImageIcon(url3);
 
  static URL url4 = JpcapPacketCapture.class.getResource("images/Print.gif");
  static ImageIcon print = new ImageIcon(url4);
 
  static URL url5 = JpcapPacketCapture.class.getResource("images/Exit.gif");
  static ImageIcon exit = new ImageIcon(url5);
 
  static URL url6 = JpcapPacketCapture.class.getResource("images/About.gif");
  static ImageIcon about = new ImageIcon(url6);
 
  static URL url7 = JpcapPacketCapture.class.getResource("images/Logo_Small.gif");
  static ImageIcon logoSmall = new ImageIcon(url7);
 
  static URL url8 = JpcapPacketCapture.class.getResource("images/Logo_Large.gif");
  static ImageIcon logoLarge = new ImageIcon(url8);
 
  static URL url9 = JpcapPacketCapture.class.getResource("images/Splash_Scrn.jpg");
  static ImageIcon splashScrn = new ImageIcon(url9);
 
  public JpcapPacketCapture()
  {
    super("Jpcap Packet Capture Version 1.00");
 
    ShowSplashScreen(4000);
 
    FileMenu fileMenu = new FileMenu(this);
    HelpMenu helpMenu = new HelpMenu(this);
    MenuBar menuBar = new MenuBar();
    menuBar.add(fileMenu);
    menuBar.add(helpMenu);
    setMenuBar(menuBar);
 
    JToolBar toolBar = new JToolBar();
    toolBar.setFloatable(true);
    toolBar.setOrientation(JToolBar.HORIZONTAL);
    toolBar.setRollover(true);
    addButtons(toolBar);
 
    textArea = new JTextArea(14, 42);
    textArea.setTabSize(4);
    textArea.setFont(new Font("sansserif", Font.PLAIN, 12));
    textArea.setCaretPosition(textArea.getDocument().getLength());
    textArea.setEditable(false);
 
    Container contentPane = getContentPane();
 
    JPanel panel = new JPanel();
 
    contentPane.add(new JScrollPane(textArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
      JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS));
 
    contentPane.add(toolBar, "North");
  }
 
  class FileMenu extends Menu
  {
    public FileMenu(JpcapPacketCapture mw)
    {
      super("File");
 
      jpcapPacketCapture = mw;
      MenuItem mi;
 
      add(mi = new MenuItem("Start Capure"));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent e)
          {
            StartCapture();
          }
        }
      );
 
      add(mi = new MenuItem("Stop Capure"));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent e)
          {
            StopCapture();
          }
        }
      );
 
      add(mi = new MenuItem("Clear Window"));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent e)
          {
        textArea.setText("");
          }
        }
      );
 
      add(mi = new MenuItem("Print Window"));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent e)
          {
            PrintWindow();
          }
        }
      );
 
      add(mi = new MenuItem("Exit"));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent e)
          {
          System.exit(0);
          }
        }
      );
    }
  }
 
  class HelpMenu extends Menu
  {
    public HelpMenu(JpcapPacketCapture mw)
    {
      super("Help");
      jpcapPacketCapture = mw;
      MenuItem mi;
 
      add(mi = new MenuItem("About..."));
      mi.addActionListener
      ( new ActionListener()
        {
          public void actionPerformed(ActionEvent evt)
          {
          JOptionPane.showMessageDialog(frame,
            "Jpcap Packet Capture Version 1.00                                   \n\n" +
            "This progoram uses Jpcap to capture packets for one of this system's  \n" +
            "network interfaces. The specific network interface to capture packets \n" +
            "for is provided by the user through a program selection dialog.       \n\n",
            "About...", JOptionPane.INFORMATION_MESSAGE, new ImageIcon(logoLarge.getImage()));
          }
        }
      );
    }
  }
 
  public void addButtons(JToolBar toolBar)
  {
    JButton toolbarButtons = null;
 
    toolbarButtons = new JButton(new ImageIcon(start.getImage()));
    toolbarButtons.setToolTipText("Start capture.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
          StartCapture();
        }
      }
    );
    toolBar.add(toolbarButtons);
 
    toolbarButtons = new JButton(new ImageIcon(stop.getImage()));
    toolbarButtons.setToolTipText("Stop capture.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
          StopCapture();
        }
      }
    );
    toolBar.add(toolbarButtons);
 
    toolbarButtons = new JButton(new ImageIcon(clear.getImage()));
    toolbarButtons.setToolTipText("Clear window.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
        textArea.setText("");
        }
      }
    );
    toolBar.add(toolbarButtons);
 
    toolbarButtons = new JButton(new ImageIcon(print.getImage()));
    toolbarButtons.setToolTipText("Print window.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
          PrintWindow();
        }
      }
    );
    toolBar.add(toolbarButtons);
 
    toolbarButtons = new JButton(new ImageIcon(exit.getImage()));
    toolbarButtons.setToolTipText("Exit program.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
        System.exit(0);
        }
      }
    );
    toolBar.add(toolbarButtons);
 
    toolbarButtons = new JButton(new ImageIcon(about.getImage()));
    toolbarButtons.setToolTipText("About program.");
    toolbarButtons.addActionListener
    ( new ActionListener()
      {
        public void actionPerformed(ActionEvent e)
        {
          JOptionPane.showMessageDialog(frame,
            "Jpcap Packet Capture Version 1.00                                                    \n \n" +
              "This progoram uses Jpcap to capture packets for one of this system's  \n" +
       "network interfaces. The specific network interface to capture packets \n" +
       "for is provided by the user through a program selection dialog.       \n\n",
       "About...", JOptionPane.INFORMATION_MESSAGE, new ImageIcon(logoLarge.getImage()));
        }
      }
    );
    toolBar.add(toolbarButtons);
  }
 
  public void receivePacket(Packet packet)
  {
    //
    // Show captured packets in the application's text area.
    //
    if (packet == null)
    {
      textArea.append("Null packet receievd or timeout");
      return;
    }
 
    textArea.append("" + packet + "\n");
  }
 
  public void StartCapture()
  {
  //
  // Get a list of eligible network interfaces.
  //
  NetworkInterface[] devices = JpcapCaptor.getDeviceList();
 
    String[] names = new String[devices.length];
 
    for (int i = 0; i < names.length; i++)
      names[i] = i + "  " + (devices[i].description == null?devices[i].name :mrgreen: evices[i].description);
 
  //
  // Get which network interface to use for capturing from the user.
  //
  Object[] selectionValues = names;
 
    String initialSelection = names[0];
 
    Object selection = JOptionPane.showInputDialog(null, "Capture using which interface?\n",
      "Input", JOptionPane.PLAIN_MESSAGE, null, selectionValues, initialSelection);
 
    textArea.append(selection + "\n");
    textArea.select(0, 1);
    interfaceNo = Integer.parseInt(textArea.getSelectedText());
 
    try
    {
      lineEndOffset = textArea.getLineEndOffset(0);
    }
    catch (Exception e)
    {
    }
 
    textArea.select(3, lineEndOffset);
    String interfaceDescription = textArea.getSelectedText();
    textArea.setText("");
 
    //
    // Open the network interface for capturing.
    //
    try
    {
      jpcapCaptor = JpcapCaptor.openDevice(devices[interfaceNo], 65535, false, 20);
    }
    catch (IOException ioException)
    {
      textArea.append("Error: " + ioException);
    }
 
    //
    // Verify which network interface the user selected to use for capturing.
    //
    textArea.append("Starting packet capture using...\n");
    textArea.append("  �  Interface " + interfaceNo + "\n");
    textArea.append("  �  " + interfaceDescription + "\n");
 
    //
    // Start capturing
    //
    jpcapCaptor.loopPacket(10, this);
  }
 
  public void StopCapture()
  {
    //
    // Stop capturing.
    //
    jpcapCaptor.close();
  }
 
  public void PrintWindow()
  {
    final MessageFormat header = new MessageFormat("");
    final MessageFormat footer = new MessageFormat("");
    textArea.setFont(new Font("sansserif", Font.PLAIN, 9));;
    try
    {
      textArea.print(header, footer, true, null, null, true);
    }
    catch(Exception e)
    {
      e.printStackTrace();
    }
 
    textArea.setFont(new Font("sansserif", Font.PLAIN, 12));
  }
 
  protected static ImageIcon createImageIcon(String path)
  {
    java.net.URL imgURL = JpcapPacketCapture.class.getResource(path);
    if (imgURL != null)
    {
      return new ImageIcon(imgURL);
    }
    else
    {
      System.err.println("Couldn't find file: " + path);
      return null;
    }
  }
 
  public void ShowSplashScreen(int d)
  {
    duration = d;
 
    JPanel splashScreen = (JPanel)getContentPane();
    int width = 470;
    int height =255;
    Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
    int x = (screen.width-width) / 2;
    int y = (screen.height-height) / 2;
    setBounds(x, y, width, height);
    JLabel label = new JLabel(new ImageIcon(splashScrn.getImage()));
    splashScreen.add(label, BorderLayout.CENTER);
    setVisible(true);
 
    try
    {
      Thread.sleep(duration);
    }
    catch (Exception e)
    {
    }
 
    splashScreen.remove(label);
    setVisible(false);
  }
 
  public static void main(String[] args)
  {
    JpcapPacketCapture jpcapPacketCapture = new JpcapPacketCapture();
    JFrame.setDefaultLookAndFeelDecorated(true);
    jpcapPacketCapture.setIconImage(logoSmall.getImage());
    jpcapPacketCapture.setSize(600, 360);
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    int w = jpcapPacketCapture.getSize().width;
    int h = jpcapPacketCapture.getSize().height;
    int x = (dim.width - w) / 2;
    int y = (dim.height - h) / 2;
    jpcapPacketCapture.setLocation(x, y);
    jpcapPacketCapture.setVisible(true);
  }
}

[Rob Spoor]

Check out JProgressBar Doesn't Update. Although these days, SwingWorker is a much nicer way to solve it.