This book teaches the Java programming language to people who are familiar with basic programming concepts. It explains the language without being arduously formal or complete. This book is not an introduction to object-oriented programming, although some issues are covered to establish a common terminology. Other books in this series and much online documentation focus on applets, graphical interfaces, Web sites, databases, components, and other specific kinds of programming tasks. For other references, see "Further Reading" on page 755.This fourth edition provides integrated coverage of the Java programming language as provided by the Java? 2 Platform Standard Edition 5.0 and specified by the Java? Language Specification, Third Edition. It also covers most of the classes in the main packages (java.lang, java.util, java.io) as implemented in the J2SE? Development Kit 5.0 (more commonly known as JDK 5.0, or in the older nomenclature JDK 1.5.0).If you have already read the third edition of this book, you will find some major changes, both in the language and the book, since the 1.3 release that the third edition covered. There are new chapters on generics, enums, and annotationsthe major new language features introduced in the 5.0 releaseand major new sections on assertions and regular expressions. Some existing material has been restructured to accommodate other changes and to improve the general flow of the textsuch as introducing the new boxing and unboxing conversions. But every single chapter has been updated in some way, whether it is a new language feature like variable argument methods; the new enhanced for loop construct; a new class such as Formatter for formatting text output; or changes to classes and methods caused by the addition of generics (such as the collections utilities and the reflection classes)change permeates this entire fourth edition.The Java programming language shares many features common to most programming languag