An Introduction to
Object-Oriented
Programming with
Java
TMC. Thomas Wu
Naval Postgraduate School
M l McGraw-Hill
Boston Burr Ridge, IL Dubuque, IA Madison, WI New York San Francisco St. Louis Bangkok Bogota Caracas Lisbon London Madrid Mexico City Milan New Delhi Seoul Singapore Sydney Taipei Toronto
Contents
Preface xiii
Major Features xiv Supplement Materials xxii Book Organization xxiv Acknowledgments xxvi
Introduction to Computers and Programming Languages 1
0.1 A History of Computers 2 0.2 Computer Architecture 5 0.3 Programming Languages 11 0.4 Java 13
0.5 Exercises 14
Introduction to Object-Oriented Programming and
Software Development 15
1.1 Classes and Objects 16 1.2 Messages and Methods 19 1.3 Class and Instance Data Values 24 1.4 Inheritance 27
1.5 Software Engineering and Software Life Cycle 30 1.6 Having Fun with Java 32
Contents
Java Programming Basics
2.1 The First Java Application 40 2.2 Program Components 49 2.3 Edit-Compile-Run Cycle 59 2.4 The javabook Package 62
2.5 Sample Program: Displaying Messages 63 2.6 The First Java Applet 68
2.7 Exercises 78
Numerical Data
3.1 Variables 84
3.2 Arithmetic Expressions 92 3.3 Constants 98
3.4 The Math Class 100
3.5 InputBox 103 3.6 OutputBox 106
3.7 Sample Program: Loan Calculator 113 3.8 Numerical Representation (Optional) 125 3.9 Exercises 129
Defining Instantiable Classes
4.1 Defining Instantiable Classes 142 4.2 Instantiable Classes and Constructors 154 4.3 Visibility Modifiers: public and private 159
4.4 Local Variables, Return Values, and Parameter Passing 164 4.5 Loan Calculator Program with an Instantiable Class 170 4.6 Exercises 185
Contents ix
Processing Input with Applets 195
5.1 Placing GUI Objects on Applets 196
5.2 Adding an Action Listener to an Event Source 204 5.3 Absolute Positioning of GUI Objects 211
5.4 The Button Class 212
5.5 Converting Text to a Numerical Value 215
5.6 Sample Program: Finding Body Mass Index (BMI) 218 5.7 Running an Applet as an Application 229
5.8 Exercises 230
Selection Statements 235
6.1 The if Statement 236
6.2 Boolean Expressions and Variables 244 6.3 Nested-if Statements 249
6.4 ListBox 256
6.5 The switch Statement 260
6.6 Sample Program: Drawing Shapes 266 6.7 Exercises 289
Repetition Statements 297
7.1 The while Statement 298
7.2 Pitfalls in Writing Repetition Statements 302 7.3 The do-while Statement 307
7.4 ResponseBox 312
7.5 The for Statement 317 7.6 Nested for Statements 322 7.7 The Format Class 325 7.8 Loan Tables 332
X Contents
7.10 (Optional) Recursive Methods 349 7.11 Exercises 353
Characters and Strings 365
8.1 Characters 366 8.2 Strings 369
8.3 Primitive versus Reference Types 381
8.4 StringBuffer 389
8.5 Passing Objects as Parameters 396 8.6 Returning an Object from Methods 401 8.7 Sample Program: Word Play 404 8.8 Exercises 417
425
Arrays
9.1 y.z 9.3 9.4 9.5 9.6 9.7 9.8 Array Basics 426 Arrays of Objects 435Passing Arrays to Methods 446 MultilnputBox 452
Self-Referencing Pointer 455
Sample Development: The Address Book 462 Two-Dimensional Arrays 480
Exercises 488
File Input and Output 493
10.1 File and FileDialog Objects 494 10.2 Low-Level File I/O 500 10.3 High-Level File I/O 506 10.4 Handling Exceptions 513 10.5 Object I/O 519
Contents
10.6 Sample Class: Saving an AddressBook Object 522 10.7 Exercises 531
Reusable Classes and Packages 535
11.1 Object Categories 536
11.2 Method Overriding and Overloaded Methods 538 11.3 Sample Classes: Reusable EggyPeggy and HiLo 545 11.4 Package Organization 572
11.5 Exercises 575
GUI Objects and Event-Driven Programming 581
12.1 Placing Buttons on a Frame 583 12.2 Handling Events 589
12.3 Placing TextField Objects on a Frame 596 12.4 Menus 598
12.5 Handling Mouse Events 605 12.6 Other GUI Objects 615
12.7 Sample Program: A Simple Calculator 620 12.8 Exercises 633
Inheritance and Polymorphism 639
13.1 Defining Classes with Inheritance 640
13.2 Using Classes Effectively with Polymorphism 645 13.3 Inheritance and Member Accessibility 648 13.4 Inheritance and Constructor 654
13.5 Abstract Superclasses and Abstract Methods 659 13.6 When and When Not to Use Inheritance 665 13.7 Sample Program: Computing Course Grades 667 13.8 Exercises 689
XII Contents
Class Roster Maintenance Program 695
14.1 Method Call Sequence Diagram 696 14.2 Problem Statement 697
14.3 Overall Planning 698
14.4 Step 1 Development: Program Shell with Menus 701 14.5 Step 2 Development: Create a New Roster 708 14.6 Step 3 Development: Add Students 716 14.7 Step 4 Development: Delete Students 724 14.8 Step 5 Development: Edit Student Names 728
14.9 Step 6 Development: Edit Test Scores and Compute Grades 734 14.10 Step 7 Development: Display Student Information 741
14.11 Step 8 Development: Storing Grade Rosters 754 14.12 Step 9 Development: Finalize and Improve 764 14.13 The StudentNameDialog Class 765
14.14 The TestScoreDialog Class 775
14.15 Exercises 780
Searching, Sorting, and Recursive Algorithms 785
15.1 Searching 786 15.2 Sorting 792 15.3 Recursion 800
15.4 When Not to Use Recursion 817 15.5 Exercises 819
