import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.net.*;
import java.io.*;
                    public class Browser extends JPanel {
                      public Browser() {
                        setLayout (new BorderLayout ());
                        final JEditorPane jt = new JEditorPane();
                        final JTextField input = 
                          new JTextField("http://www.tpu.ee");
                        jt.setEditable(false);
                        // reageeri viidetele
                        jt.addHyperlinkListener(new HyperlinkListener () {
                          public void hyperlinkUpdate(
                              final HyperlinkEvent e) {
                            if (e.getEventType() == 
                                HyperlinkEvent.EventType.ACTIVATED) {
                              SwingUtilities.invokeLater(new Runnable() {
                                public void run() {
                                  Document doc = jt.getDocument();
                                  try {
                                    URL url = e.getURL();
                                    jt.setPage(url);
                                    input.setText (url.toString());
                                  } catch (IOException io) {
                                    //vahetus ebaõnnestus
                                    veateade();
                                    jt.setDocument (doc);
                                  }
                                }
                              });
                            }
                          }
                        });
                        JScrollPane pane = new JScrollPane();
                        pane.setBorder (
                          BorderFactory.createLoweredBevelBorder());
                        pane.getViewport().add(jt);
                        add(pane, BorderLayout.CENTER);

                        input.addActionListener (new ActionListener() {
                          public void actionPerformed (ActionEvent e) {
                            try {
                              jt.setPage (input.getText());
                            } catch (IOException ex) {
 										veateade();
                            }
                          }
                        });
                        add (input, BorderLayout.SOUTH);
                        try{jt.setPage(input.getText());}
                        catch(IOException e){veateade();}
                      }
                      
                      void veateade(){
                              JOptionPane.showMessageDialog (
                                Browser.this, "Vigane URL", 
                                "Tõenäoliselt vigane URL", 
                                JOptionPane.ERROR_MESSAGE);                      
                      }
                      
                      public static void main(String argumendid[]){
                        JFrame f=new JFrame("Brauser");
                        f.getContentPane().add(new Browser());
                        f.setSize(300, 300);
                        f.setVisible(true);
                      }
                    }