Check type for HyperlinkEvent in Java

/* w w w. j a va  2s .  com*/
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileNotFoundException;
import java.net.IDN;

import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;
import javax.swing.text.html.HTMLDocument;
import javax.swing.text.html.HTMLFrameHyperlinkEvent;

public class Main extends JFrame implements HyperlinkListener {
  private JTextField txtURL= new JTextField("");
  JEditorPane ep = new JEditorPane();
  private JLabel lblStatus= new JLabel(" ");

  public Main() {
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    JPanel pnlURL = new JPanel();
    pnlURL.setLayout(new BorderLayout());
    pnlURL.add(new JLabel("URL: "), BorderLayout.WEST);
    pnlURL.add(txtURL, BorderLayout.CENTER);
    getContentPane().add(pnlURL, BorderLayout.NORTH);
    getContentPane().add( ep, BorderLayout.CENTER);

    getContentPane().add(lblStatus, BorderLayout.SOUTH);

    ActionListener al = new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        try {
          String url = ae.getActionCommand().toLowerCase();
          if (url.startsWith("http://"))
            url = url.substring(7);
          ep.setPage("http://" + IDN.toASCII(url));
        } catch (Exception e) {
          e.printStackTrace();
          JOptionPane.showMessageDialog(Main.this, "Browser problem: " + e.getMessage());
        }
      }
    };
    txtURL.addActionListener(al);

    setSize(300, 300);
    setVisible(true);
  }
  public void hyperlinkUpdate(HyperlinkEvent he) {
    HyperlinkEvent.EventType type = he.getEventType();
    if (type == HyperlinkEvent.EventType.ENTERED) {
        System.out.println(he.getURL().toString());
    } else if (type == HyperlinkEvent.EventType.EXITED) {
      System.out.println("Exited");
    } else if (type == HyperlinkEvent.EventType.ACTIVATED) {
      if (he instanceof HTMLFrameHyperlinkEvent) {
        HTMLFrameHyperlinkEvent evt = (HTMLFrameHyperlinkEvent) he;
        HTMLDocument doc = (HTMLDocument) ep.getDocument();
        doc.processHTMLFrameHyperlinkEvent(evt);
      } else {
        try {
          ep.setPage(he.getURL());
          System.out.println(he.getURL().toString());
        } catch (FileNotFoundException fnfe) {
          ep.setText("Could not open file: <tt>" + he.getURL() + "</tt>.<hr>");
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }
  }

  public static void main(String[] args) {
    new Main();
  }
}