This is an almanac; and, true to its name, it packs a LOT of information into a SMALL package. Thorough and yet concise, it has the highest content-to-page ratio of any programming reference I have seen. The Java classes are big and the _Java Developers Almanac_ is the tool to use to quickly find the details needed to get programs running. It is a great help for rapid prototyping in new application areas, and to fine-tune and polish the finished product. The "traditional" class documentation found in other reference books can be tiring, frustrating and time consuming to use because it usually only describes what is new to a class, leaving it to the reader to flip around to chase up the inheritance tree to see everything. The "Almanac" tells everything for every class. While this may be a redundant use of paper and ink, it is a great time saver to the programmer trying to use a new class.
This is not a book to learn Java or object oriented programming. This is an excellent reference for the experienced object oriented programmer.
The _Java Developers Almanac_ is a "must have" reference for contractors and "road warrior" programmers who only have a briefcase for an office.