This is of the breed of reference manual that is not simply a bare-bones description, but comes with a reasonable amount of example material as well, which makes it a far more readable and educational proposition. That said, it is not the type of book that most people would choose to learn Java from. (Although there are those of us who actually prefer to learn from reference texts, as their authors are less likely to omit or skip over material which they may view as of little interest, but which may be highly relevant to us).
The question then is, is this the book to have as your desktop companion? It does not cover as much ground as Java in a Nutshell (2nd Edition) , as it is limited in scope to the language itself and the
java.langclasses, (version 1.1 in this edition), albeit it goes down to a much greater depth. You will need some documentation of the other standard packages as well, which makes for a rather expensive proposition.
So while the quality of this book is very high - it has the clearest exposition of inner classes for example that I have read - it has to be recognised that its readership is going to be limited to serious programmers with a pretty generous book budget.