I am SJCP as of 05/2000. That's 13 years ago (70%). Things have moved on in Java. Even though I use Java all the time and write in it fluently, I now (reluctantly) realize my Java skills are insufficient and out-of-date.
I am looking for a book or website to learn Java in-depth through 1.7. These sources need not begin with elementary Java (although they could start with fundamentals); they have to cover all aspects of core Java thoroughly.
A good book I have found is Effective Java, by Joshua Bloch. But useful as this book is, I want one which systematically and rigorously reviews core features of the language. For example, I understand pretty well basic interface definition, use them all the time, and when to use an interface as opposed to an abstract class. I could write an interface without having to look up how to do this. But, for example, I did not understand questions about how to extend interfaces that make use of generics in their signatures. Also, for example, I need to learn in detail the new concurrency model.
I would like, for example, a thorough detailing of Garbage Collection.
It could well be a prep specifically for the Oracle Java certification exams, but need not be.
Any ideas about books, websites, forums (other than this great one!), etc. are welcome and appreciated!