Java Tutorial/Development/JNLP
An Example JNLP File
<?xml version="1.0" encoding="utf-8"?>
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@(#)webpad.jnlp 1.3 02/07/29
Copyright (c) 2002 Sun Microsystems, Inc. All Rights Reserved.
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This software is provided "AS IS," without a warranty of any kind. ALL
EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
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OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
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<jnlp spec="1.0" codebase="http://localhost/jws" href="Notepad.jnlp">
<information>
<title>Notepad Demo</title>
<vendor>Sun Microsystems, Inc.</vendor>
</information>
<resources>
<property name="jnlp.publish-url" value="$$context/publish"/>
<j2se version="1.3+" href="http://java.sun.ru/products/autodl/j2se"/>
<jar href="Notepad.jar"/>
</resources>
<application-desc main-class="Notepad"/>
</jnlp>
File: index.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Java Web Start Demo</TTLE>
</HEAD>
<BODY>
<H1>Java Web Start Demo</H1>
This link is to the Notepad.jnlp file.
</BODY>
</HTML>
Uses the JNLP API to open and save files
/*
*
* Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import javax.jnlp.*;
public class JWSFileChooserDemo extends JPanel
implements ActionListener {
static private final String newline = "\n";
JButton openButton, saveButton;
JTextArea log;
public JWSFileChooserDemo() {
super(new BorderLayout());
//Create the log first, because the action listeners
//need to refer to it.
log = new JTextArea(5,20);
log.setMargin(new Insets(5,5,5,5));
log.setEditable(false);
JScrollPane logScrollPane = new JScrollPane(log);
//Create the open button. We use the image from the JLF
//Graphics Repository (but we extracted it from the jar).
openButton = new JButton("Open a File...",
createImageIcon("images/Open16.gif"));
openButton.addActionListener(this);
//Create the save button. We use the image from the JLF
//Graphics Repository (but we extracted it from the jar).
saveButton = new JButton("Save a File...",
createImageIcon("images/Save16.gif"));
//PENDING: removed the Save button action listener
//so that people won"t overwrite existing files.
//See bug 4761577.
//saveButton.addActionListener(this);
saveButton.setEnabled(false);
//For layout purposes, put the buttons in a separate panel
JPanel buttonPanel = new JPanel();
buttonPanel.add(openButton);
buttonPanel.add(saveButton);
//Add the buttons and the log to this panel.
add(buttonPanel, BorderLayout.PAGE_START);
add(logScrollPane, BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent e) {
//Handle open button action.
if (e.getSource() == openButton) {
FileOpenService fos = null;
FileContents fileContents = null;
try {
fos = (FileOpenService)ServiceManager.
lookup("javax.jnlp.FileOpenService");
} catch (UnavailableServiceException exc) { }
if (fos != null) {
try {
fileContents = fos.openFileDialog(null, null);
} catch (Exception exc) {
log.append("Open command failed: "
+ exc.getLocalizedMessage()
+ newline);
log.setCaretPosition(log.getDocument().getLength());
}
}
if (fileContents != null) {
try {
//This is where a real application would do something
//with the file.
log.append("Opened file: " + fileContents.getName()
+ "." + newline);
} catch (IOException exc) {
log.append("Problem opening file: "
+ exc.getLocalizedMessage()
+ newline);
}
} else {
log.append("User canceled open request." + newline);
}
log.setCaretPosition(log.getDocument().getLength());
}
//Handle save button action.
if (e.getSource() == saveButton) {
FileSaveService fss = null;
FileContents fileContents = null;
ByteArrayInputStream is = new ByteArrayInputStream(
(new String("Saved by JWSFileChooserDemo").getBytes()));
//XXX YIKES! If they select an
//XXX existing file, this will
//XXX overwrite that file.
try {
fss = (FileSaveService)ServiceManager.
lookup("javax.jnlp.FileSaveService");
} catch (UnavailableServiceException exc) { }
if (fss != null) {
try {
fileContents = fss.saveFileDialog(null,
null,
is,
"JWSFileChooserDemo.txt");
} catch (Exception exc) {
log.append("Save command failed: "
+ exc.getLocalizedMessage()
+ newline);
log.setCaretPosition(log.getDocument().getLength());
}
}
if (fileContents != null) {
try {
log.append("Saved file: " + fileContents.getName()
+ "." + newline);
} catch (IOException exc) {
log.append("Problem saving file: "
+ exc.getLocalizedMessage()
+ newline);
}
} else {
log.append("User canceled save request." + newline);
}
log.setCaretPosition(log.getDocument().getLength());
}
}
/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = JWSFileChooserDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn"t find file: " + path);
return null;
}
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("JWSFileChooserDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
JComponent newContentPane = new JWSFileChooserDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application"s GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
