Its a book which should be read by every java programmer.its for beginners in java, every topic that a good java programmer should know like memory management, classes, objects, data types etc are explained in such a real way.
and the best part of the book is that its easy to read, and the puzzles and riddles given after each topic are just amazing and worth to spend a lot of time to think that.its a books that every java learner should read from the beginning.