You should think of Java (and any other techonolgy) as a tool. sometimes, a hammer is the best tool, and sometime a screwdriver is better.
You don't say "I want to use a screwdriver, how do i build a picnic table". You figure out what you want to end up with, and THEN decide what are the best tools to use. Should you buy your lumber pre-cut (costs more, but simpler and not as flexible) or should you purchase stock lumber and a table saw? or would a hand saw do?
I always worry when i hear "We're going to re-do everything in XYZ, because XYZ is the FUTURE". There are times when that is the WRONG solution.
just my 2 cents.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors