عمل متصفح ويب باستخدام لغة الجافا

// Fig. 27.3: ReadServerFile.java
// Reading a file by opening a connection through a URL.
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;
import javax.swing.JFrame;

public class ReadServerFileTest
{
public static void main( String[] args )
{
ReadServerFile application = new ReadServerFile();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
} // end main
} // end class ReadServerFileTest



class ReadServerFile extends JFrame
{
private JTextField enterField; // JTextField to enter site name
private JEditorPane contentsArea; // to display website

// set up GUI
public ReadServerFile()
{
super( "Simple Web Browser" );

// create enterField and register its listener
enterField = new JTextField( "Enter file URL here" );
enterField.addActionListener(
new ActionListener()
{
// get document specified by user
public void actionPerformed( ActionEvent event )
{
getThePage( event.getActionCommand() );
} // end method actionPerformed
} // end inner class
); // end call to addActionListener

add( enterField, BorderLayout.NORTH );

contentsArea = new JEditorPane(); // create contentsArea
contentsArea.setEditable( false );
contentsArea.addHyperlinkListener(
new HyperlinkListener()
{
// if user clicked hyperlink, go to specified page
public void hyperlinkUpdate( HyperlinkEvent event )
{
if ( event.getEventType() ==
HyperlinkEvent.EventType.ACTIVATED )
getThePage( event.getURL().toString() );
} // end method hyperlinkUpdate
} // end inner class
); // end call to addHyperlinkListener

add( new JScrollPane( contentsArea ), BorderLayout.CENTER );
setSize( 400, 300 ); // set size of window
setVisible( true ); // show window
} // end ReadServerFile constructor

// load document
private void getThePage( String location )
{
try // load document and display location
{
contentsArea.setPage( location ); // set the page
enterField.setText( location ); // set the text
} // end try
catch ( IOException ioException )
{
JOptionPane.showMessageDialog( this,
"Error retrieving specified URL", "Bad URL",
JOptionPane.ERROR_MESSAGE );
} // end catch
} // end method getThePage
} // end class ReadServerFile