I'm currently in the middle of trying to program some data structures in Java while the first 2 years of my college curriculum were in C++ and I dabbled a little in Java my last semester, but it wasn't all too involved. I bought O'Reilly's Learning Java, but I find myself looking at the API frequently and wondering things, like how to use/construct Iterator classes or something like toArray functions and not having any clue how they work. Google often turns up just discriptions and nothing too indepth and I'm looking for clear examples, ie code, of how to implement and use them. Are there any books that do just that? That will take something like, Interfaces and really show me how to use them effectively without having to go through stuff like for loops? I'm really desparate because these concepts dont seem to be too difficult but being able to code is what is hindering me.