Create Android library jar to work with non-Android project

Question

I am working on a library that ideally will have a strictly-Java component and added functionality for Android-specific projects, with the intent to be most useful for Android apps, but also work with other Java apps.

But my question is: how should this be designed? I do not plan on needing resources, so I want to compile it into a JAR, but would I need to make two JARs, one of the Java stuff and another for the Android stuff? Or would a Java-only application be able to use a single JAR so long as it does not use the Android components?

Answer 1

If you make a library that uses pure java and does not use any android apis. It will work on both standard java and android java. However if the library uses any android apis it can't be used in a standard java project.

Answer 2

As far as I know, the JAR would be good for both types of aplications. It seems to mee that both JARs (just Java and android) are totally identical and thus equally compatible. If you don't use any of the android components, including Resources there should not be a problem at all.

You should still check whether you depend on libraries which are available on android and any normal Java distribution or -if not- either tell the user to preinstall the depending libraries or ship them whitin your JAR package and build path. Be carefull not to use libraries which are not available on android because the user has no or really few options to install them on himself.

What I don't understand is why you think your library is more usefull to android developers. I can not think of any example where this could happen. If the problem is really specific for android, you should consider developing the library android-only. If the problem is more general the lib will be usefull to all developers that might come to this problem, not just android.