Reviewed by Matthew E. Ferris
President, Chicagoland Java User Group
Sun Certified Java Programmer

Programmers have come to expect a certain format and quality from O'Reilly titles, and this latest Java offering does not disappoint. To their already meaty catalog of Java books, comes Java I/O, solidifying O'Reilly's place as just about the best friend a developer has.

The labyrinth of classes associated with doing I/O in Java is indeed daunting; I have thrown my hands up more than once wondering why simply reading text from a file needs to involve so many handshakes. Mr. Harold does a good job of explaining that many of the reasons Java I/O is the way it is has to do with cross-platform capabilities of the language. In an orderly fashion, he walks the reader through the various classes and subclasses of the API that allow you to do input and output. Starting with the abstract superclasses that form the basis of all I/O in Java, the author builds a solid foundation for understanding their descendant classes, why one subclass is better suited to a given task, and the performance implications of various methods of I/O.

However, basic input and output are not the only items covered in the book. There are chapters on working with zip files, serialized streams and cryptographic streams. I found particularly helpful the discussion of the various character sets that starts the book out.
It is not uncommon to use a book like this simply for reference - you need to do something fairly quickly and you want an example of how it is done. The book is full of examples that should satisfy that need. My one complaint is that O'Reilly doesn't make it too easy to get to the example code online. When one goes to the page covering this title at the O'Reilly site, there is not a link there for the examples, and I could not get to their ftp site for some reason.
If you want clever cartoons in the margins, and a (shallow) promise of learning a complex topic in 24 hours - look elsewhere. But if you want an in-depth look at a complicated topic - I recommed this book.