I had an urgent need to learn Java quickly and bought several books: SAMS Java 2, Deitel&Deitel's How to Program Java to name but two, but this book is the best by far.
Pretty much all basic principles are demonstrated in the first few chapters, and backed up with some great examples. Also, the first chapters resist from telling you everything about a principle or class which avoids confusion and allow you to build a complete picture of the language in your head.
Later chapters concrete over your knowledge and fill in the gaps - it's much easier to understand than the other books that I started to read because you have all the basic principles from a very early stage.
In combination with the JAVA and JAVA ENTERPRISE IN A NUTSHELL books, this makes an excellent resource.