Question

I know this question has come up in some form, one way or another. However, a lot of them are outdated, so I figured I’d ask again plus also ask the real reason for this question.

Both Android and BB development can be accomplished via Java, and while Android adds a lot of classes and functionality on top of the Java SDK, Blackberry seems to rely on Java’s J2ME. If I write an application that targets both platforms, especially from a media playback perspective, how much code reuse can I expect between both platforms? For the record, a PhoneGap based app is not possible (esp due to BB’s implementation of Webkit).

Answer 1

I work on a large app which shares common code across Android, BlackBerry, MIDP, and J2SE (i.e. Desktop Java). I would say that about 75% of the code on a given platform is common code.

Pros:

• One lot of code to develop/test. This is a huge positive!
• If you ever decide to port to other platforms, you’ve already done most of it.

Cons:

• You’re limited to java 1.3 compatibility in the common code (no annotations, collections, etc).
• UI differences can be a pain, particularly with the different event models. MVC is your friend here – at least you can share the model!
• You’ll want to write wrapper classes for all the platform-dependent stuff which needs to interact with your common code. This is extra code which you wouldn’t have to write if you weren’t code sharing.

Whether it’s going to be worth your while depends on a few things… I’d at least think about the following:

1. How large is the project? (Larger = more of a case for sharing code.)
2. How much of your core functionality is realistically going to be shareable? You mention media playback – if that’s going to be 80% of your app’s code then it’s probably not worth the effort to set up shared code.
3. How familiar are you with the different platforms? (More familiar = more idea of the potential pitfalls = more likely to know which code should be shared and how to structure it.)