Question

I have seen programs like http://one-jar.sourceforge.net/ and http://fjep.sourceforge.net/index.html promote rolling your application jar and any dependencies into a single, executable jar.

What are the main reasons for/against doing this?

Answer 1

For:

• easier distribution,
• makes classpath problem go away,
• can be packaged even in Ms PowerPoint presentation as a clickable icon, probably OpenOffice also can handle it.

Against:

• difficult packaging – sometimes you hit a corner case such as: how to package native extensions,
• requires extra build step,
• generates larger jars,
• can violate library’s license agreement,
• kills the notion of library reuse,
• makes updates and
• debugging (because of extra classpath loader) more difficult.

So generally, it’s really a great way for quick prototyping, but can get in a way if used in a bigger project.