The power of Java lies in the pre-defined functionality provided by the Java platform application programming interface (API). The Java platform API consists of a collection of packages that each contains a set of classes and interfaces ready for use in your programs.
Detailed Java platform API documentation can be found on the Java website: [ java.sun.com ]
The key to discovering the functionality provided by a certain class or component is to trace its inheritance hierarchy. The Java platform API documentation gives an inheritance hierarchy diagram on each class detail page. Scroll down the detail page to see what methods a class inherits from its chain of base classes.
This book will focus on and utilize a small subset of the total functionality provided by the Java platform API. However, armed with the ability to navigate an inheritance hierarchy, you can easily discover and include in your programs additional Java platform functionality not formally discussed in the text.