Remember though that the class path only refers to previously compiled code. I'm using packages and including the details in the class path, but I'm still getting NoClassDefFoundError exceptions. You need to put the base directory of the package in the class path, rather than the actual directory with the class in it. Package directory names are case sensitive too, so if you changed the example directory to Example the Java run time wouldn't be able to find the class files any more. The code is compressed in a ZIP file, which you will need to decompress before you can use it.
Nobody is perfect and mistakes do occur.
Firstly, you can check if the error has already been reported. All known errata for Wrox books are stored here. The best place to install the documentation is the same folder that you installed the JDK into. After unzipping, your JDK directory will have a new subdirectory called docs . I'm trying to use packages to organise my classes, but I get errors when compiling my program.