Making a jar of an android project to use in another android project?

I made an android project using eclipse. It looks like:

src/
   ActivityMain.java
   lib/
      Square.java
      Circle.java

I want to export only the /lib package really as a jar (don't want to include stuff at the top level like ActivityMain.java). Are there any special rules I need to be aware of before jar-ing this for use in ano开发者_开发技巧ther android project, or I should be all set?

Thanks

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Bear in mind that Square and Circle cannot reference resources (at least not via R. syntax), and that JARs cannot package resources, manifest entries, etc. If all you are trying to JAR up is pure Java code (perhaps using Android APIs), then you should be fine.