Books are good to learn new concepts, but to actually understand the concepts and know when the right times to use them are, takes practice and no amount of boo

Books are good to learn new concepts, but to actually understand the concepts and know when the right times to use them are, takes practice and no amount of books will make up for lack of practice here. So, since you have already read a number of books, I would say that practice is the most important thing for you now. Also, in time, you will want to learn other programming languages to give you a more rounded experience of what is available both in terms of tools and also concepts which will help shape how you think about and solve problems in java. Ideally you would learn a number of very different languages. At the very least a functional language as this even help you a lot when you begin writing multithreaded programs in java (and also help you design simpler, more composable code). But for now, practice. Try to set yourself real projects or actually useful tasks and make sure you complete them (ie don't have a load of unfinished projects, but finish them to the point that you could release them to non-programmers if you wanted). Projects should range from both large and small to give you experience and practice working on a range of codebase sizes.