Java Web Start

Java Web Start is a technology built into the current generation of Java Runtimes. A user can start an application from the web by clicking on a link -this triggers the download and caching of the manifest of the application. The manifest lists which JAR artifacts are to be downloaded, their versions and where to retrieve them, and the entry point of the application. The runtime downloads any artifacts that are not already stored in the cache, then starts the application.

Features

Advantages

• Allows swing applications to be downloaded and run.
• Signed manifests and artifacts enables downloads to be secured.
• If the remote server is polled every time the application is started up, changes can be rolled out fast.
• The manifests allow some per-machine options, including native libraries.]
• A central Java Web Start manager application can list which applications have been downloaded, and purge them on demand.
• Artifact caching enables off-line operation and reduces startup time when on-line.
• Polling for changes creates loggable events that can be used to measure application use.

Disadvantages

• The current implementation of Java Web Start does not download updates to [Endorsed Java Libraries]. This prevents Java Web Start applications for downloading updates to APIs/implementations that are bundled in the JRE, such as JAX-WS in Java 6.
• Signed artifacts are granted total rights to the underlying system; it is the ActiveX problem. You cannot trust third parties to have good intent.

SmartFrog support

We've experimented with publishing SmartFrog as a Java Web start application, as a way of providing a quick-start runtime for demonstrations. The source for this is available in the repository. However, we have not found it a viable method for pushing out updates to server farms, as it is focused on client applications. Users have to start the application and may have to respond to prompts.