Nam Voth
Posts: 1
Nickname: oliver7
Registered: Mar, 2002
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AppletToDisplayWebPage
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Posted: Mar 6, 2002 11:54 AM
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This prog is from Java How to prog(Deitel & Deitel-4th Edition).The html codes followed are to display the SiteSelector applet.
Why does the applet display in Applet Viewer when I run the html file from there but when I use Internet Explorer or Netscape to display the webpage it won't.
Can anyone help me with this.
Many thanks in advance
Nam
import java.net.*;
import java.util.*;
import java.awt.*;
import java.applet.AppletContext;
import java.applet.*;
// Java extension packages
import javax.swing.*;
import javax.swing.event.*;
public class SiteSelector extends JApplet {
private Hashtable sites; // site names and URLs
private Vector siteNames; // site names
private JList siteChooser; // list of sites to choose from
// read HTML parameters and set up GUI
public void init()
{
// create Hashtable and Vector
sites = new Hashtable();
siteNames = new Vector();
// obtain parameters from HTML document
getSitesFromHTMLParameters();
// create GUI components and layout interface
Container container = getContentPane();
container.add( new JLabel( "Choose a site to browse" ),
BorderLayout.NORTH );
siteChooser = new JList( siteNames );
siteChooser.addListSelectionListener(
new ListSelectionListener() {
// go to site user selected
public void valueChanged( ListSelectionEvent event )
{
// get selected site name
Object object = siteChooser.getSelectedValue();
// use site name to locate corresponding URL
URL newDocument = ( URL ) sites.get( object );
// get reference to applet container
AppletContext browser = getAppletContext();
// tell applet container to change pages
browser.showDocument( newDocument );
}
} // end anonymous inner class
); // end call to addListSelectionListener
container.add( new JScrollPane( siteChooser ),
BorderLayout.CENTER );
} // end method init
// obtain parameters from HTML document
private void getSitesFromHTMLParameters()
{
// look for applet parameters in the HTML document
// and add sites to Hashtable
String title, location;
URL url;
int counter = 0;
// obtain first site title
title = getParameter( "title" + counter );
// loop until no more parameters in HTML document
while ( title != null ) {
// obtain site location
location = getParameter( "location" + counter );
// place title/URL in Hashtable and title in Vector
try {
// convert location to URL
url = new URL( location );
// put title/URL in Hashtable
sites.put( title, url );
// put title in Vector
siteNames.add( title );
}
// process invalid URL format
catch ( MalformedURLException urlException ) {
urlException.printStackTrace();
}
++counter;
// obtain next site title
title = getParameter( "title" + counter );
} // end while
} // end method getSitesFromHTMLParameters
} // end class SiteSelector
this is the html file:
<html>
<title>Site Selector</title>
<body>
<applet code="SiteSelector.class" width="300" height="75">
<param name="title0" value="Java Home Page">
<param name="location0" value="http://java.sun.com/">
<param name="title1" value="Deitel">
<param name="Location1" value="http://www.deitel.com/">
<param name="title2" value="JGuru">
<param name="location2" value="http://www.jGuru.com/">
<param name="title3" value="JavaWord">
<param name="location3" value="http://www.javaworld.com">
</applet>
</body>
</html>
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