Java 2: The Complete Reference

1186 Pages·2002·16.141 MB·English

by  Herbert Schildt

Java 2:
™
The Complete Reference,
Fifth Edition
About the Author
HerbertSchildtistheworld’sleading
programmingauthor.Heisanauthorityonthe
C,C++,Java,andC#languages,andisamaster
Windowsprogrammer.Hisprogrammingbooks
havesoldmorethat3millioncopiesworldwide
andhavebeentranslatedintoallmajorforeign
languages.Heistheauthorofnumerous
bestsellers,includingJava2:TheComplete
Reference,Java2:ABeginner'sGuide,Java2
ProgrammersReference,C++:TheComplete
Reference,C:TheCompleteReference,andC#:
TheCompleteReference.Schildtholdsamaster's
degreeincomputersciencefromtheUniversity
ofIllinois.Hecanbereachedathisconsulting
officeat(217)586-4683.
Java 2:
™
The Complete Reference,
Fifth Edition
Herbert Schildt
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DOI: 10.1036/007222858X
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Contents at a Glance
Part I The Java Language
1 The Genesis of Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 An Overview of Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3 Data Types, Variables, and Arrays . . . . . . . . . . . . . . . . . . . . . . . 41
4 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5 Control Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6 Introducing Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
7 A Closer Look at Methods and Classes . . . . . . . . . . . . . . . . . . . 155
8 Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
9 Packages and Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
10 Exception Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
11 Multithreaded Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
12 I/O, Applets, and Other Topics . . . . . . . . . . . . . . . . . . . . . . . . . 313
v
vi Java™ 2: The Complete Reference
Part II The Java Library
13 String Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
14 Exploring java.lang . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
15 java.util Part 1: The Collections Framework . . . . . . . . . . . . . . . 439
16 java.util Part 2: More Utility Classes . . . . . . . . . . . . . . . . . . . . . 505
17 Input/Output: Exploring java.io . . . . . . . . . . . . . . . . . . . . . . . . 537
18 Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 587
19 The Applet Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627
20 Event Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 653
21 Introducing the AWT: Working with Windows,
Graphics, and Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 687
22 Using AWT Controls, Layout Managers, and Menus . . . . . . . 735
23 Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799
24 New I/O, Regular Expressions, and Other Packages . . . . . . . 843
Part III Software Development Using Java
25 Java Beans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 885
26 A Tour of Swing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 921
27 Servlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949
28 Migrating from C++ to Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981
Part IV Applying Java
29 The DynamicBillboard Applet . . . . . . . . . . . . . . . . . . . . . . . . . . 1011
30 ImageMenu: An Image-Based Web Menu . . . . . . . . . . . . . . . . 1047
31 The Lavatron Applet: A Sports Arena Display . . . . . . . . . . . . 1057
32 Scrabblet: A Multiplayer Word Game . . . . . . . . . . . . . . . . . . . . 1069
A Using Java’s Documentation Comments . . . . . . . . . . . . . . . . . . 1133
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1141
Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv
Part I
The Java Language
1 The Genesis of Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Java’s Lineage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
The Birth of Modern Programming: C . . . . . . . . . . . . . . . . . . . . . . . 4
The Need for C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The Stage Is Set for Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The Creation of Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The C# Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Why Java Is Important to the Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Java Applets and Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Portability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Java’s Magic: The Bytecode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
The Java Buzzwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Simple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Object-Oriented . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
vii
viii Java™ 2: The Complete Reference
Robust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Multithreaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Architecture-Neutral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Interpreted and High Performance . . . . . . . . . . . . . . . . . . . . . . . . . 14
Distributed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Dynamic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
The Continuing Revolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2 An Overview of Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Object-Oriented Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Two Paradigms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Abstraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
The Three OOP Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
A First Simple Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Entering the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Compiling the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
A Closer Look at the First Sample Program . . . . . . . . . . . . . . . . . . 27
A Second Short Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Two Control Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
The if Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
The for Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Using Blocks of Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Lexical Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Whitespace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Separators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
The Java Keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
The Java Class Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3 Data Types, Variables, and Arrays . . . . . . . . . . . . . . . . . . . . . . 41
Java Is a Strongly Typed Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
The Simple Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Integers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
short . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
int . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Floating-Point Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
double . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Booleans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
A Closer Look at Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Integer Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Floating-Point Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Boolean Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51