October 22, 2003: The Lopica project is now distributing WebStartEx. The Lopica project is a collection of goodies for Java WebStart, so WebStartEx fits perfectly in the picture!
It is distributed in a package called "webstart-wrapper".

July 19, 2003: I think it is time to publish this useful program that enhances WebStart applications. So here is the site where to find it, and eventually updates or news.

The Java Web Start technology is a great deployment technology but I found a limitation: resources must be bundled in some Jar files so complex manipulations of files are not possible.
WebStartEx is a program that simplifies the deployment of an application that was not designed with Web Start in mind, or that requires more freedom.

WebStartEx unjars the desired application to a cache directory and runs it. The working directory is set to the cache directory and no feature from WebStart is lost!
The original jar files content is removed but timestamps and some small information are kept so that the update mechanisms work correctly.
If some jar files content should not be emptied (used by several application, i.e. a common library) it is possible to specify it.

WebStartEx is programmed with the idea to not lose any advantage Web Start offers.
It supports automatic updates when some files are added/deleted/modified.
The original application that is jared is unjared to a cache directory, and the original jar files are emptied to save space (unless specified differently).
Removing the application does remove the cache directory (assuming the configuration of the JNLP file is correct).