disky: er er ikke tale om IE, det er Netscape der nævnes,
så API'en forklarer INTET. Måske man skulle læse
spørgsmålene før man svarer?
nielsbrinch: Det du referere til som værende problemet
er det ren html eller er det diverse avancerede plugins?
Prøv denne version har lavet der er en primitiv browser:
SimpleBrowser.java
//package Janet;
//import Janet.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
import java.io.*;
import java.net.*;
import java.awt.print.*;
/**
* Class SimpleBrowser is an extension of {@link JFrame}
* that works as a simple browser.
* The functionality is as described here:
* <UL>
* <LI>Buttons
* <UL>
* <LI><B>Back</B> will move one page back in the history.
* <LI><B>Forward</B> will move one page forward in the history.
* <LI><B>Reload</B> will reload the current page.
* <LI><B>Save</B> will save the contents of the current page
* (unless the address has been modified in which case it will
* attempt to save the page associated with this new address).
* <LI>The tilde button adds a tilde to the address in the
* text field and has been included because some systems
* have problems entering the character from the keyboard.
* </UL>
* <LI>The text field is used to enter a URL pointing to
* a document. Pressing the enter key in the text field
* leads to the page being loaded into the text area.
* <LI>Text area functionality
* <UL>
* <LI>Clicking on a hyperlink will lead to a new page
* being displayed if it represents a valid hyperlink
* with an accessible page.
* <LI>Pressing the shift key and cliking the mouse away from
* a hyperlink leads to a popup menu appearing.
* In the popup menu is a list of all hyperlinks in the
* currently displayed page, and they can be followed
* by clicking on the desired one.
* Clicking elsewhere will dismiss the list.
* </UL>
* </UL>
* <BR><B>Note:</B><BR>
* <UL>
* <LI>The class uses a JEditorPane which may throw exceptions that
* cannot be caught, hence disturbing messages may be printed
* to the console, but does not always impair the functionality.
* <LI>Frames are not fully supported, especially with respect
* to the history.
* </UL>
* <BR><B>Example of use:</B><BR>
* SimpleBrowser browser = new SimpleBrowser( "SimpleBrowser" );
* browser.show();
* @author Carsten Knudsen
* @author Martin Egholm Nielsen
* @version 1.0
**/
public class SimpleBrowser extends JFrame implements Serializable {
private final static String initialGreeting = "<HTML><CENTER><B>Welcome to the SimpleBrowser</B></CENTER></HTML>";
private final static String initialWebAddress = "
http://www.fys.dtu.dk/~janet"; private JTextField address;
private boolean standAlone;
private final JEditorPane pane;
private final JPopupMenu menu;
private java.util.List history = new java.util.ArrayList();
private int historyPointer = -1;
private Listener listener;
private final ActionListener buttonListener;
private JButton back;
private JButton forward;
private JButton reload;
private JButton save;
private JButton tilde;
/**
* Constructor for SimpleBrowser class taking as argument
* a title.
**/
public SimpleBrowser( String title ) {
this( title, false );
}
/**
* Constructor for SimpleBrowser class taking as argument
* a title and a boolean indicating whether the SimpleBrowser
* should run as a stand-alone application.
**/
private SimpleBrowser( String title, boolean standAlone ) {
super( title );
this.standAlone = standAlone;
JFrame frame = this;
JLabel messageField = new JLabel( " " );
pane = new JEditorPane();
//pane = new FormattedPane();
pane.setEditable( false );
pane.setContentType( "text/html" );
pane.setFont( new Font( "Monospaced", Font.BOLD, 16 ) );
pane.setText( initialGreeting );
pane.setCaretPosition( 0 );
Box box = Box.createHorizontalBox();
back = new JButton( "Back" );
back.setToolTipText( "Move one step back in the history." );
forward = new JButton( "Forward" );
forward.setToolTipText( "Move one step forward in the history." );
reload = new JButton( "Reload" );
reload.setToolTipText( "Reload the current page." );
save = new JButton( "Save" );
save.setToolTipText( "Save the referenced contents in a file." );
Insets insets = new Insets( 0, 0, 0, 0 );
back.setMargin( insets );
forward.setMargin( insets );
reload.setMargin( insets );
save.setMargin( insets );
box.add( back );
box.add( forward );
box.add( reload );
box.add( save );
JLabel spaces = new JLabel( " " );
address = new JTextField( initialWebAddress );
tilde = new JButton( "~" );
tilde.setMargin( insets );
tilde.setToolTipText( "Press button to append a ~(tilde) to address." );
box.add( spaces );
box.add( address );
box.add( tilde );
listener = new Listener( frame, pane,
forward, back, reload, save,
messageField, address, tilde );
forward.addActionListener( listener );
back.addActionListener( listener );
reload.addActionListener( listener );
save.addActionListener( listener );
pane.addHyperlinkListener( listener );
address.addActionListener( listener );
tilde.addActionListener( listener );
JPanel panel = new JPanel();
panel.setLayout( new BorderLayout() );
panel.add( box, BorderLayout.NORTH );
panel.add( new JScrollPane( pane ), BorderLayout.CENTER );
panel.add( messageField, BorderLayout.SOUTH );
getContentPane().add( panel );
setSize( 600, 600 );
addWindowListener( new CloseWindow() );
menu = new JPopupMenu();
buttonListener = new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
menu.setVisible( false );
addPage( ae.getActionCommand() );
} // actionPerformed
} ;
pane.addMouseListener( new MouseAdapter() {
public void mouseReleased( MouseEvent me ) {
int x = me.getX();
int y = me.getY();
if ( me.isPopupTrigger() || me.isShiftDown() ) {
setupPopupMenu();
try {
Object o = menu.getComponent( 0 );
menu.show( pane, x, y );
} // try
catch ( ArrayIndexOutOfBoundsException aioobe ) {
} // catch
} // if
else if ( me.isControlDown() ) {
setupImgSrcMenu();
try {
Object o = menu.getComponent( 0 );
menu.show( pane, x, y );
} // try
catch ( ArrayIndexOutOfBoundsException aioobe ) {
} // catch
} // if
} // mouseDragged
} // MouseAdapter
);
//ComponentPrinter.makePrintable( pane );
} // constructor
private void clearPopupMenu() {
boolean more = true;
while ( more ) {
try {
menu.remove( 0 );
} // try
catch ( IllegalArgumentException iae ) {
more = false;
} //catch
} // more
} // clearPopupMenu
private void setupPopupMenu() {
clearPopupMenu();
Document document = pane.getDocument();
if ( document instanceof HTMLDocument ) {
HTMLDocument htmldoc = (HTMLDocument)document;
HTMLDocument.Iterator iterator = htmldoc.getIterator( HTML.Tag.A );
iterator.next();
while ( iterator.isValid() ) {
AttributeSet attr = iterator.getAttributes();
boolean found = false;
Enumeration enum = attr.getAttributeNames();
while ( enum.hasMoreElements() && ! found ) {
Object name = enum.nextElement();
if ( name.equals( HTML.Attribute.HREF ) ) {
found = true;
Object value = attr.getAttribute( name );
boolean problem = false;
URL url = null;
try {
url = new URL( (String)value );
} // try
catch ( MalformedURLException murle ) {
problem = true;
} // catch
if ( ! problem ) {
JButton button = new JButton( (String)value );
menu.add( button );
button.addActionListener( buttonListener );
} // if
} // if
} // while
iterator.next();
} // while
} // if
} // setupPopupMenu
private void setupImgSrcMenu() {
clearPopupMenu();
Document document = pane.getDocument();
if ( document instanceof HTMLDocument ) {
HTMLDocument htmldoc = (HTMLDocument)document;
HTMLDocument.Iterator iterator = htmldoc.getIterator( HTML.Tag.IMG );
iterator.next();
while ( iterator.isValid() ) {
AttributeSet attr = iterator.getAttributes();
boolean found = false;
Enumeration enum = attr.getAttributeNames();
while ( enum.hasMoreElements() && ! found ) {
Object name = enum.nextElement();
if ( name.equals( HTML.Attribute.SRC ) ) {
found = true;
Object value = attr.getAttribute( name );
boolean problem = false;
URL url = null;
try {
url = new URL( (String)value );
} // try
catch ( MalformedURLException murle ) {
problem = true;
} // catch
if ( ! problem ) {
JButton button = new JButton( (String)value );
menu.add( button );
button.addActionListener( buttonListener );
} // if
} // if
} // while
iterator.next();
} // while
} // if
} // setupImgSrcMenu
/**
* The class Listener handles all events related to displaying
* information in the SimpleBrowser.
* It handles buttons being pressed and hyperlinks being activated.
**/
private class Listener
implements ActionListener, HyperlinkListener {
private JFrame frame;
private JEditorPane pane;
private JButton forward, back, reload, save;
private JLabel messageField;
private JTextField address;
private JButton tilde;
/**
* Public constructor for class Listener.
**/
public Listener( JFrame frame,
JEditorPane pane,
JButton forward,
JButton back,
JButton reload,
JButton save,
JLabel messageField,
JTextField address,
JButton tilde ) {
this.frame = frame;
this.pane = pane;
this.forward = forward;
this.back = back;
this.reload = reload;
this.save = save;
this.messageField = messageField;
this.address = address;
this.tilde = tilde;
this.forward.setEnabled( false );
this.back.setEnabled( false );
this.reload.setEnabled( false );
this.save.setEnabled( false );
} // constructor
// handles button events
public void actionPerformed( ActionEvent ae ) {
try {
Object source = ae.getSource();
if ( source.equals( forward ) ) {
if ( historyPointer < history.size() - 1 ) {
Cursor oldCursor = frame.getCursor();
frame.setCursor( new Cursor( Cursor.WAIT_CURSOR ) );
URL url = (URL)history.get( ++historyPointer );
try {
pane.setPage( url );
address.setText( url.toString() );
} // try
catch ( Exception e ) {
} // catch
frame.setCursor( oldCursor );
updateButtons();
}
} // if, forward
else if ( ae.getActionCommand().equals( "Back" ) ) {
if ( historyPointer > 0 ) {
Cursor oldCursor = frame.getCursor();
frame.setCursor( new Cursor( Cursor.WAIT_CURSOR ) );
URL url = (URL)history.get( --historyPointer );
try {
pane.setPage( url );
address.setText( url.toString() );
} // try
catch ( Exception e ) {
} // catch
frame.setCursor( oldCursor );
updateButtons();
}
} // else if, back
else if ( ae.getActionCommand().equals( "Reload" ) ) {
if ( historyPointer > 0 ) {
Cursor oldCursor = frame.getCursor();
frame.setCursor( new Cursor( Cursor.WAIT_CURSOR ) );
URL url = (URL)history.get( historyPointer );
try {
pane.setPage( url );
address.setText( url.toString() );
} // try
catch ( Exception e ) {
} // catch
frame.setCursor( oldCursor );
updateButtons();
}
} // else if, back
else if ( source.equals( tilde ) ) {
address.setText( address.getText() + "~" );
} // else if, tilde
// the user have pressed enter in the address field
else if ( source.equals( address ) ) {
try {
URL url = new URL( ae.getActionCommand() );
pane.setPage( url );
address.setText( url.toString() );
if ( historyPointer > -1 ) {
while ( history.size() - 1 > historyPointer ) {
history.remove( history.size() - 1 );
} // while
history.add( url );
historyPointer++;
updateButtons();
} // if
else {
history.add( url );
historyPointer++;
updateButtons();
} // else
} // try
catch ( MalformedURLException murle ) {
showErrorMessage( "" + murle );
redisplayCurrentPage();
} // catch
catch ( IOException ioe ) {
showErrorMessage( "" + ioe );
redisplayCurrentPage();
} // catch
catch ( NullPointerException npe ) {
showErrorMessage( "" + npe );
redisplayCurrentPage();
} // catch
} // else if, address
else if ( source.equals( save ) ) {
JFileChooser fileChooser = new JFileChooser( new File( System.getProperty( "user.dir" ) ) );
fileChooser.setFileSelectionMode( JFileChooser.FILES_ONLY );
fileChooser.setApproveButtonText( "Save" );
fileChooser.setApproveButtonToolTipText( "Click to save to file." );
int result = fileChooser.showOpenDialog( null );
if ( result == JFileChooser.APPROVE_OPTION ) {
try {
File file = fileChooser.getSelectedFile();
FileOutputStream fos = new FileOutputStream( file );
URL url = new URL( address.getText() );
URLConnection connection = url.openConnection();
InputStream is = connection.getInputStream();
byte[] buffer = new byte[ 8192 ];
int bytes_read;
while( ( bytes_read = is.read( buffer ) ) > 0 ) {
fos.write( buffer, 0, bytes_read );
} // while
fos.close();
is.close();
} // try
catch ( IOException ioe ) {
JOptionPane.showMessageDialog( null,
"IO exception: " + ioe.getMessage(),
"Error",
JOptionPane.ERROR_MESSAGE );
} // catch
} // try
} // else if, save
} // try
// mysterious exceptions are somtimes thrown hence the try-catch CK
catch( Exception q ) {
} // catch
} // actionPerformed
// handles hyperlink events
public void hyperlinkUpdate( HyperlinkEvent e ) {
HyperlinkEvent.EventType type = e.getEventType();
if ( type == HyperlinkEvent.EventType.ACTIVATED ) {
JEditorPane pane = (JEditorPane) e.getSource();
if ( e instanceof HTMLFrameHyperlinkEvent ) {
HTMLFrameHyperlinkEvent evt = (HTMLFrameHyperlinkEvent)e;
HTMLDocument doc = (HTMLDocument)pane.getDocument();
doc.processHTMLFrameHyperlinkEvent(evt);
} // if
else {
try {
URL url = e.getURL();
pane.setPage( url );
address.setText( url.toString() );
updateHistory( url );
updateButtons();
} // try
catch ( MalformedURLException murle ) {
showErrorMessage( "" + murle );
} // catch
catch ( IOException ioe ) {
showErrorMessage( "" + ioe );
} // catch
catch ( NullPointerException npe ) {
showErrorMessage( "" + npe );
} // catch
} // else
} // if
else if ( type == HyperlinkEvent.EventType.ENTERED ) {
messageField.setText( e.getDescription() );
} // else if
else if ( type == HyperlinkEvent.EventType.EXITED ) {
messageField.setText( " " );
} // else if
} // hyperlinkUpdate
} // class Listener
/**
* This methods enables or disables the forward and back buttons
* depending on the historyPointer and history list.
**/
private void updateButtons() {
if ( historyPointer < 0 ) {
forward.setEnabled( false );
back.setEnabled( false );
reload.setEnabled( false );
save.setEnabled( false );
} // if
else {
if ( historyPointer >= 0 ) {
reload.setEnabled( true );
save.setEnabled( true );
} // if
else {
reload.setEnabled( false );
save.setEnabled( false );
} // else
if ( historyPointer > 0 ) {
back.setEnabled( true );
} // if
else {
back.setEnabled( false );
} // else
if ( historyPointer < history.size() - 1 ) {
forward.setEnabled( true );
} // if
else {
forward.setEnabled( false );
} // else
} // else
} // updateButtons
/**
* This method updates the history function with the given URL.
**/
private void updateHistory( URL url ) {
if ( historyPointer > -1 ) {
while ( history.size() - 1 > historyPointer ) {
history.remove( history.size() - 1 );
}
history.add( url );
historyPointer++;
updateButtons();
}
else {
history.add( url );
historyPointer++;
updateButtons();
}
} // updateHistory
private void redisplayCurrentPage() {
URL url = (URL)history.get( historyPointer );
try {
pane.setPage( url );
} // try
catch ( Exception e ) {
} // catch
} // redisplayCurrentPage
/**
* Adds a URL referenced by the text to the browser,
* and updates the history, as well as the button state.
**/
public void addPage( String text ) {
try {
URL url = new URL( text );
pane.setPage( url );
address.setText( url.toString() );
if ( historyPointer > -1 ) {
while ( history.size() - 1 > historyPointer ) {
history.remove( history.size() - 1 );
} // while
history.add( url );
historyPointer++;
updateButtons();
} // if
else {
history.add( url );
historyPointer++;
updateButtons();
} // else
} // try
catch ( MalformedURLException murle ) {
showErrorMessage( "" + murle );
} // catch
catch ( IOException ioe ) {
showErrorMessage( "" + ioe );
} // catch
catch ( NullPointerException npe ) {
showErrorMessage( "" + npe );
} // catch
} // addPage
/**
* Display en error message passed as argument.
**/
private static void showErrorMessage( String message ) {
JOptionPane.showMessageDialog( null,
message,
"Error",
JOptionPane.ERROR_MESSAGE );
} // showErrorMessage
/**
* The public method setWebAddress sets the web address that
* appears in the SimpleBrowser.
**/
public void setInitialWebAddress( String webAddress ) {
address.setText( webAddress );
} // setInitialWebAddress
/**
* The class CloseWindow makes it possible for the browser
* to be shut down by clicking in the right hand corner.
**/
private class CloseWindow extends WindowAdapter implements Serializable {
public void windowClosing( WindowEvent e ) {
if ( standAlone )
System.exit( 0 );
else
dispose();
} // windowClosing
} // CloseWindow
/**
* Method main allows SimpleBrowser to work as a stand-alone application.
**/
public static void main( String[] args ) {
SimpleBrowser browser = new SimpleBrowser( "SimpleBrowser", true );
browser.setVisible( true );
} // main
} // SimpleBrowser
