Generally, how long it will take a java programmer who knows J2SE to master EJB concept and use it in programming? What's its prerequisites(what're the must-have java APIs and non-java technology, concepts, thoughts, philosophy, traning and background)?
Modern software design has been based on some thoughts and lessons from previous software engineering that help people gradually formulating a set of clearly stated questions(WHYs), trying answer these questions we're given, say, EJB(the HOWs). Unfortunately, when we try to learn the new achievement,lots of WHYs are missing(undocumented), or just some dry statements, what we see are a huge statements of HOWs. Many things are taken for granted by the designers, but it's not always the case that a learner will think so. For most people, the difficulty is not HOWs, but WHYs. The WHYs are algebra, HOWs are just arithmetic. When I tried to learn EJB, I clearly felt that there are somethings around or beneath it, it's just those things that bar me from getting a thorough understanding of EJB. For you who already climbed the mountain, could you please tell me what I should prepare well before I begin to study it?
It's said EJB will greatly simplify the development of enterprise computing, but I don't know if it also makes IT manager's work simpler to find a qualified java developer.
thanks a lot