Web Start Help

The first time a user downloads a Web Start application, they need to download the Java Web Start client. That client includes a JVM and an application manager that allows the user to configure Web Start and any downloaded Web Start applications.

You can try downloading Ptolemy II as a Web Start application by going to http://ptolemy.eecs.berkeley.edu/ptolemyII/ptII2.0/webstart.htm

Web Start Features:

The best thing about Web Start is that it is easy to update a small part of the application and then the next time the users run the app, they will download just the updated portion instead of having to download the entire application and reinstall.

The way Web Start works is that developers create jar files that are collections of Java .class files, images, platform dependent libraries and other resources. An application consists of multiple jar files and a .jnlp file that describes the application.

Since shipping a standalone installer usually requires splitting an application up into components anyway, then the exercise of building jar files is a useful one, since the jar files could be used for other installers such as InstallAnywhere or InstallShield. I use Web Start as a test bed for figuring out which files need to be shipped. Using Web Start for this is usually much faster than running InstallAnywhere or InstallShield, since if there is a problem in only one jar file, then only that jar file is affected, and I don't necessarily need to rebuild a large installer.

In theory, one can ship one large jar file, but that makes updating the application more difficult, since if the application changes, the entire jar file will be downloaded unless a somewhat more complex jar diff system is used.

The jar files and the .jnlp file may or may not be signed by using a Sun Java code signing certificate. If all the jars are signed, then the application can have access to the local disk, and basically looks like a regular application. If the jars are not signed, then access is limited. It is also possible to run the application in 'sandbox' mode, which is fairly restrictive, but can still do some useful things.

One can use a temporary code signing certificate and eventually pay Verisign $400/year for a permanent code signing certificate.

Installing Web Start

The basic procedure is that one installs Web Start itself and then restarts your browser and downloads the Web Start enabled application.

1. Usually, the web page that includes the Web Start enabled application download attempts to detect if you already have Web Start installed. If the Web Start detection succeeds, then you need not reinstall Web Start.
   However, the Web Start detection can fail, especially under Netscape 6. If the detection fails, the web page will contain text like:

    You need to Install Web Start from Sun before installing . . .
   

2. You may already have Web Start installed, so you may want to try clicking on the Web Start enabled application download and if you have Java Web start installed, either:
   the Java Web Start splash screen should come up and the download should start.
   or you should see a window that asks if you want to download the file or start up javaws. Click on Open using javaws.exe and then OK, and the Java Web Start splash screen should come up.
   If the Java Web Start splash screen comes up, then need not reinstall Web Start.
3. If the Java Web Start splash screen did not appear, then download Java Web Start from http://java.sun.com/cgi-bin/javawebstart-platform.sh?
4. Click on the Java Web Start installer executable
5. Usually, the default location of c:\Program Files\Java Web Start is fine
6. You may need to restart your browser and go back to the Web Start enabled application download page.
7. Note that the Ptolemy II Web Start applications may be signed with a certificate that is not registered with a certificate authority, so you may be prompted with a window stating that the certificate from Claudius Ptolemaus is unknown. You should hit the OK button to proceed with the download

Java Web Start Application Manager

Troubleshooting Web Start

Help while installing

Limitations while installing

Installing Java 3D for use with Web Start

There are problems with Java 3D 1.2.1_03 API under JDK1.4.0, when I run a Java3D app, we get:

Fail to create back buffer - DDERR_INALIDPARAM

The workaround is to use JDK1.3.1

Below are some instructions on installing Java3D: Go to http://java.sun.com/products/java-media/3D/download.html and download Java 3D for Windows (DirectX Version) Runtime for the JRE

Click on the installer. Eventually, it will prompt you for the JRE to install Java 3D in. You should install it under the same JRE that you are running in Web Start. There are at least two ways to determine which JRE you are running:

1. 1) Start up Ptolemy, go to a model, do View -> JVM Properties and look at the java.home property. The value of the java.home property should be something like C:\Program Files\JavaSoft\Java\j2re1.4.2 This value is the JRE that Java 3D should be installed in.
2. Start up the Web Start Application Manager and do File -> Preferences -> Java and look at the command column of the table. The Ptolemy II Web Start edition will use a JVM that is 1.4 or later.

Netscape 6

A quick test is to click on one of the Vergil downloads and if you have Java Web start installed, either:

The Java Web Start FAQ at http://java.sun.com/products/javawebstart/faq.html#11 says:

What are the supported browsers? JavaTM Web Start supports primarily Internet Explorer 4 or higher and Netscape 4.X. However JNLP files can be launched from any browser if the mime-type association is done correctly. Please note that JavaTM Web Start uses the browsers settings and may launch a browser to show a URL these may/may not work with unsupported browsers.

JavaTM Web Start works with Netscape 6. However, you will manually need to register JavaTM Web Start with NS6. This is done in the Navigator/Applications section of the Navigator/Helper Application section. This will be done automatically in a later version of the JavaTM Web Start installer. back to top

Netscape 6 Java Web Start Set up Instructions

1. If necessary, download Java Web Start from http://java.sun.com/cgi-bin/javawebstart-platform.sh?
2. Click on the Java Web Start download and install it.
3. In Netscape 6, go to the preferences window: Edit -> Preferences
4. Click on Navigator in the left hand Category pane
5. Click on Helper Applications
6. The File type application/x-java-jnlp-file should be listed. If it is, you are done, click on OK
7. If application/x-java-jnlp-file was not listed, click on New Type

   Description of type:

   Java Web Start

   File extension:

   JNLP

   MIME Type:

   application/x-java-jnlp-file

   Application to use

   Choose to the javaws.exe binary, usually c:\Program Files\Java Web Start\javaws.exe

8. Click on OK to close the New Type window
9. Click on OK to close the Preference window
10. You should now be able to download Java Web Start applications.

Help while running

Limitations while running

Drive not ready message

Drive not Ready . . .
Abort Retry Cancel

For more information, see

Troubleshooting for developers

Remote Java Web Start Resources

How Web Start .jnlp files are built in Ptolemy II

$PTII/mk/jnlp.mk contains the rules that process the *jnlp.in files and generates *.jnlp files.

If the Web Start application is to have full access to the machine, then the application needs to be signed, which means that the .jnlp file needs to be copied into the jar file that has the main() method and the entire jar file signed.

Since we use the same main() for more than one application and each application has a separate .jnlp file, it is necessary to create a separate java class and jar file for each application. Those jar files are found in $PTII/ptolemy/actor/gui/jnlp.

File not found

java.io.FileNotFoundException: JAR entry doc/mainVergil.htm not found in 
   C:\Program Files\Java Web Start\.javaws\cache\file\D\P-1
   \DMc&c\DMusers\DMcxh\DMptII\DMptolemy\RMptolemy.jar
	at sun.net.www.protocol.jar.JarURLConnection.connect(Unknown Source)
	at sun.net.www.protocol.jar.JarURLConnection.getInputStream(Unknown Source)
	at javax.swing.JEditorPane.getStream(Unknown Source)
	at javax.swing.JEditorPane.setPage(Unknown Source)
	at ptolemy.actor.gui.HTMLViewer.setPage(HTMLViewer.java:195)
	at ptolemy.actor.gui.HTMLViewerTableau$Factory.createTableau(HTMLViewerTableau.java:169)
	at ptolemy.actor.gui.TableauFactory.createTableau(TableauFactory.java:116)
	at ptolemy.actor.gui.Configuration.createPrimaryTableau(Configuration.java:151)
	at ptolemy.actor.gui.Configuration.openModel(Configuration.java:267)
	at ptolemy.actor.gui.HTMLViewer.hyperlinkUpdate(HTMLViewer.java:139)
	at javax.swing.JEditorPane.fireHyperlinkUpdate(Unknown Source)

I had this problem several months back and putting the following
line (I put this code early in Jbinit() ):

ClassLoader loader=this.getClass().getClassLoader();
Thread.currentThread().setContextClassLoader(loader);

hope this helps, md

It turns out that is is necessary to modify Ptolemy II so that if it is looking for a resource and fails then we should try stripping out the text before the jar URL !/ separator and look for the resource in the classpath.

Another thing to look for is hrefs that are relative and use ../ instead of ptolemy/. Relative URLS will not work when looking for resources using the classpath

"Unsigned application requesting unrestricted access to system"

1. Start up Web Start, clear the cache and reload.
2. Check that the jar files are signed: cd $PTII; make jnlp_verify
   If one of the jar files will not verify, use jar -tvf file.jar to verify that the file actually has data files in it
3. Resign the jar files: cd $PTII; make jnlp_clean jnlp_all
4. Rebuild the jar files: cd $PTII; make clean install

Bad Mime Type

Bad MIME type returned from server when accessing resource: 
   http://www.gigascale.org/ptolemy/src/ptII/vergil.jnlp - text/html

Spaces in path names