Java in a Nutshell, 4th Edition

Chapters 2 and 3 documented the Java programming language. This chapter switches gears and covers the Java platform -- a vast collection of predefined classes available to every Java program, regardless of the underlying host system on which it is running. The classes of the Java platform are collected into related groups, known as packages. This chapter begins with an overview of the packages of the Java platform that are documented in this book. It then moves on to demonstrate, in the form of short examples, the most useful classes in these packages. Most of the examples are code snippets only, not full programs you can compile and run. For fully fleshed-out, real-world examples, see Java Examples in a Nutshell (O'Reilly). That book expands greatly on this chapter and is intended as a companion to this one.