Creating a Java application that downloads its own dependencies

Question

I'm interested in how to distribute a Java application that has a lot of dependencies (specified in a pom.xml in Maven).

Obviously it would be possible to just package everything in one big .jar file. However that seems wasteful, since an update of the application would require sending a new copy of all the dependencies as well.

So I'm looking for a way of distributing the app that does the following:

• Only includes the core application in the main .jar file
• Downloads dependencies as needed when the .jar file is run
• Keeps copies of the dependencies locally, so that if an application update is distributed the dependencies don't need to be downloaded again

What's the best way of achieving this?

Answer 1

Can you just use Maven, with something like described at Maven Run Project ?

This is how I have some of my own applications setup within my own network. I've never needed to worry about messing with the classpaths or downloading / providing dependencies for programs setup like this for a long time. This approach also meets all of your criteria.

Answer 2

you can distribute your file using the web start technology (aka distribute a jnlp file). i believe this will handle most of this functionality for you, including updatability.