You should observe a few points first:
* are you examining your own code?
* if not, is the code you are examining "good" Java? if it is, get someone knowledgeable to tell you whether it is "good" Java or not; this means is it well designed, is it structured well, is it maintainable does it follow proper design habits for software development (eg loosely, minimal use of static variables)
* does it actually run well? does not consume lots of memory over time?
Then, you might want to look and see whether the code has consideration for the nuances of the Blackberry platform, see documentation like
http://docs.blackberry.com/en/developers/deliverables/5827/BlackBerry_Java_Application_design_447305... especially the chapter on "Best practices"
