Thread: Application Auto-Updating Ideas

One of the things I am working on with my current personal project is adding an automatic updating system that checks a dropbox link for new file updates.

This thread is intended to be for brainstorming so post as many ideas as you like for how to make this work as efficiently as possible. I also am having trouble with figuring out how to keep the process platform independent...

Here are the ideas I have so far:

1. The most obvious to me is have an app launcher that simply checks for updates and, if none are available launches the main jar. If an update is available, it downloads the new jar and replaces the old one, then launches the new jar. I would rather, however, avoid the approach of having two jars/a launcher exe + jar because it would mean writing an installer which kills the platform independent goal.

2. Include the main jar inside of the launcher jar (pretty much same process as above). I'm not sure though how I would go about replacing the contents of a running jar file.... you guys may need to help me with that one.

3. Manually replace individual class files? Again I'm not sure if that is even possible...

Any ideas are appreciated!

To swap jars and a java execution, you might need a place to stand while you are doing the swaps.
It could depend on the OS.
Start another program to do the transit, End the current one. Do some cleanup. Start the new version and end the transitive program.

Originally Posted by Norm

To swap jars and a java execution, you might need a place to stand while you are doing the swaps.
It could depend on the OS.
Start another program to do the transit, End the current one. Do some cleanup. Start the new version and end the transitive program.

Yeah I came up with another idea after I posted this and it's kind of like what you just said.

I was thinking have the Launcher class run an update check method, and if there is an update, download a ZIP file with TWO jars. The new program jar and an updater program.

It extracts the ZIP and launches the updater. It then exits itself and lets the updater program take care of the cleanup, AKA delete the old jar and replace it with the new one. The updater then launches the new program and closes itself down. I suppose the main program could also check on start up for the existence of the updater and remove it to finish up the job cleanly.

How does that sound?