I am trying to extract some common classes out to be a common jar, and I want to reference it by the appengine project in Eclipse.

It compiles well but could not run. The console just told that some classes from the common jar project could not be found.

I know I can just export the project into a jar, but I may want to change it sometimes, so I prefer keep it dynamic.

And I know maven may be an option but there is no official maven support for appengine, and I will not try to learn it.

Then how can I make it work?