Java and Object Orientation: An Introduction

Transcription

1 John Hunt 2008 AGI-Information Management Consultants May be used for personal purporses only or by libraries associated to dandelon.com network. Java and Object Orientation: An Introduction Second Edition Springer

2 Contents Part 1 Introduction to Object Orientation 1 Introduction to Object Orientation Introduction Programming Paradigms Revolution Versus Evolution Why Learn a New Programming Paradigm? Software Industry Blues The Advantages Claimed for Object Orientation What Are the Problems and Pitfalls of Object Orientation? Pedigree of Object-Oriented Languages Fundamentals of Object Orientation The Basic Principles of Object Orientation Encapsulation Inheritance Abstraction Polymorphism Overloading Operators Overriding Operators Summary Further Reading 19 2 Elements of Object Orientation Introduction Terminology Types of Hierarchy The Move to Object Technology Summary Exercises Further Reading 26 3 Constructing an Object-Oriented System Introduction The Application: Windscreen Wipe Simulation Where Do We Start? Identifying the Objects Identifying the Services Or Methods Refining the Objects Bringing it All Together Where Is the Structure? Summary Exercise Further Reading 36 xv

3 xvi Contents Part 2 Introduction to the Java Language 4 A Brief History of Time, the Universe and Java Introduction What Is Java? Objects in Java History Commercial Versions of Java The Java Environment What Is in a Name? What Is JavaScript? Applications and Applets Applications in Java Further Reading Where to Get More Information 45 5 A Little Java Introduction Setting up the Development Environment Compiling and Executing Java Using the Java Documentation Tool Summary Further Reading 51 6 Java Building Blocks Introduction The Basics of the Language Some Terminology The Message-Passing Mechanism The Statement Terminator Classes Class Definitions Classes and Messages Instances and Instance Variables Classes and Inheritance Instance Creation Constructors Static Initialization Blocks Finalize Methods Supplied Classes Method Definitions... \ The Comments Section The Local Variables Section The Statements Section The Return Operator An Example Method Interface Definitions 64 7 Java Constructs Introduction Numbers and Numeric Operators Numeric Values Arithmetic Operators 68

4 Contents xvii 7.3 Characters and Strings Characters Strings Assignments Variables Temporary Variables Pseudo Variables Variable Scope Special Values-True, False and Null Messages and Message Selectors Invoking Methods Precedence Summary Further Reading 74 8 An Example Java Class Introduction Defining a Class Creating the Class Defining a Class Comment Defining a Method The main Method The Constructor The Accessor Methods The Updater Method The birthday Method Creating an Instance 78 Part 3 Java and Object Orientation 9 Classes, Inheritance and Abstraction Introduction Classes Revisited What Are Classes For? Class-Side Methods A Class or an Instance Inheritance in Classes The Role of a Subclass Capabilities of Classes Restricting a Subclass Abstract Classes Constructors and Their Use The main Method Encapsulation and Polymorphism Introduction Encapsulation Class Modifiers Variable Modifiers Method Modifiers Packages Declaring a Package An Example Package 95

5 xviii Contents Accessing Package Elements An Example of Using a Package Polymorphism Dynamic or Late Binding Method Selection Inner Classes and Reflection Introduction What Are Inner Classes? Types of Inner Class Nested Top-Level Classes Member Inner Classes Method Level/Local Inner Classes Anonymous Inner Classes How and When Should I Use Inner Classes? As Helper Classes As Event Handlers As Anonymous Event Handlers Laying Out a Java Class With Inner Classes Inner class guidelines The Reflection API Data Structures Introduction Data Structure Classes The Abstract Class Dictionary The Hashtable Class The Vector Class The Stack Class A Queue Class Enumeration Arrays Arrays of Objects Basic Type Arrays Multi-Dimensional Arrays The main Method Memory Management Why Have Automatic Memory Management? Memory Management in Java When Is Garbage Collection Performed? Checking the Available Memory Exercise: Vectors Summary Further Reading The Collections API Introduction What Is in the Collections API? Collection Interfaces Collection Set List Map 134

6 Contents xix Part Comparisons Abstract Implementations AbstractCollection AbstractSet Abstractly st AbstractSequentialList AbstractMap Concrete Implementations HashSet ArraySet ArrayList LinkedList HashMap ArrayMap TreeMap The Collections Class Iteration Over Collections Array Sorting and Searching Choosing a Col lection class Summary 144 Further Java 14 Control and Iteration Introduction Control Structures The If Statement The Conditional Operator The switch Statement Iteration for Loops while Loops do Loops An Example of Loops Recursion Summary An Object-Oriented Organizer Introduction The Organizer Class The Class Definition The Updating Protocol The Accessing Protocol The main Method Exercise - the Financial Manager Project Streams and Files Introduction Streams What Is a Stream? Readers and Writers: Character Streams Stream Tokenizers Using the 10 Classes 167

7 xx Contents 16.3, Files Accessing File Information The FileReader Class Constructors The FileWriter Class Constructors The BufferedReader Class Constructors The BufferedWriter Class Constructors The StreamTokenizer Class The PrintWriter Class Constructors Handling File 10 Errors Accessing a File Creating a File Input From the Console Summary Serialization Introduction Saving Objects Reading Objects The ObjectOutputStream Class The ObjectlnputStream Class The Serial izable Interface The transient Keyword The External izable Interface A Simple Serialization Application The Person Class The Family Class The Test Class Exercise - Using Files With the Financial Manager Summary Observers and Observables Introduction The Dependency Mechanism Why Do We Want Dependency? How Does Dependency Work? Constructing Dependencies A Simple Dependency Example Making Dependency Work for You The "Changed" Methods The Observer Interface Extending the Dependency Example Exercise - Dependency and the Financial Manager Summary ; 196 Part 5 Graphical Interfaces and Applets 19 Graphic Programming Using the Abstract Window Toolkit Introduction Windows as Objects Windows in Java The Abstract Window Toolkit The Component Class The Container Class 203

8 Contents xxi 19.7 The Panel Class The Frame Class The Graphics Class A Worked Graphical Application The ExampleFrame Class The ExamplePa.fiel Class Further Reading User Interface Programming Introduction The Event Delegation Model The Philosophy Behind the Event Model A Partial Example The Listener Interfaces GUI Component Classes The Button Class The Checkbox Class The CheckboxGroup Class The Label Class The TextComponent Class The TextField Class The TextArea Class Additional AWT Classes Managing Component Layout Introduction The Flowlayout Manager The Borderlayout Manager The GridLayout Manager The GridBagLayout Manager The CardLayout Manager A Simple GUI Example Putting the Swing into Java Introduction Swing, the JFC and the JDK What Is the MVC? Swinging the MVC Into Action Transitioning to Swing / The SimpleGallery Application A Swinging Gallery Things to Remember Online References A GUI Case Study Introduction The Model-View-Handler Architecture Event Listeners Observers and Observables Frames, Panels and Layout Managers The Class Structure The Accountlnterface Class 248

9 xxii Contents The WindowHandler class TheJPanel Classes The Handler Classes The Account Class The Instance Structure Exercise - A GUI for the Financial Manager Summary Further Reading The Lowdown on Layouts, Borders and Containers Introduction Containers in Swing Layouts for Containers, The Fl owlayout Manager The BorderLayout Manager The GridLayout Manager The GridBagLayout Manager BoxLayout OverlayLayout Borders in Swing The BorderFactory Empty Borders Li neborder class Bevel Border and SoftBevel Border EtchedBorder The MatteBorder class TheTitledBorder CompoundBorder class Using Panels, Layouts and Borders Planning a Display Online References Combining Graphics and GUI Components Introduction The SwingDraw Application The Structure of the Application The Interactions Between Objects The Draw Constructor Changing the Type of Graphic Object Adding a Graphic Object Moving a Graphic Object The Classes The SwingDraw Class The DrawMenuBar class TheDrawToolBar and ButtonPanel Classes The Tool Handler Class The Drawi ng Class The Drawi ngpanel Class The Drawi ngcontroller Class The LookAndFeel Panel Class The Drawi ngexcepti on Class The Figure Class The Square Class 295

10 Contents xxiii The Circle Class The Line Class The TextFigure Class The TextDialog Class Exercises Summary Swing Data Model Case Study... /* Introduction The JTree Swing Component The JTree Constructors The JTree API Changing the Model The JTree Package Interfaces Classes The DefaultMutableTreeNode class Building the Data Model Building the GUI Application Online Resources Java: Speaking in Tongues Introduction Locale Properties Objects ResourceBundle Introduction Naming Properties Files Property Inheritance Accessing Property Values Formatting Output Summary Online References The CUTting Edge Introduction The Simple Editor Cutting and Copying Data Pasting Data Drag and Drop , DragLabel DropTextArea Summary 331 Part 6 Internet Working 29 Sockets in Java Introduction Socket to socket communication Setting Up a Connection An Example Client-Server Application The System Structure Implementing the Server Application Implementing the Client Application 338

11 xxiv Contents 30 Applets and the Internet Introduction Applet Security The Applet Class Working With Applets The Account Applet Change the Root Class Definition Define then nit Method A Brief Introduction to HTML The <applet> HTML Tag Accessing HTML Files Swing and Applets Exercise: Tic-Tac-Toe Applet What to Do Notes Summary Further Reading Servlets: Serving Java up on the Web Introduction How Servlets Work The Structure of the Servlet API An Example Servlet Why Use Servlets? Summary Further Reading Java Server Pages Introduction What Is a JSP? A Very Simple JSP The Components of a JSP Directives Actions Implicit Objects JSP Scripting Making JSPs Interactive Why Use JSPs? Problems With JSPs 368 / 33 Java Database Connectivity Introduction WhatlsJDBC? What the Driver Provides Registering Drivers Opening a Connection Obtaining Data From a Database Creating a Table Applets and Databases Mini SQL Further Reading Online References 379

12 Contents xxv Part 7 Java Development 34 Java Style Guidelines Introduction Code Layout Variables Naming Variables Using Variables Classes Naming Classes The Role of a Class Creating New Data Structure Classes Class Comments Using a Class or an Instance Interfaces Enumerated Types Methods Naming Methods Using Methods Class Methods and Instance Methods Static Initialization Blocks Constructors The finalize Method Programming in Terms of Objects Positioning of Methods Scoping Statement Labels Exception Handling Introduction What Is an Exception? What Is Exception Handling? Throwing an Exception Catching an Exception Defining an Exception Concurrency Introduction Concurrent Processes Threads , Thread States Creating a Thread Thread Groups The Thread Class Implementing a Thread Synchronization A Time Slicing Example Using Schedulers The Time Slicing Source Code 408

13 xxvi Contents Part 8 Object-Oriented Design 37 Object-Oriented Analysis and Design Introduction Object-Oriented Design Methods Object-Oriented Analysis The Booch Method The Steps in the Booch Method Strengths and Weaknesses The Object Modeling Technique The Analysis Phase The Design Phase The Implementation Phase Strengths and Weaknesses The Objectory Method The Requirements Phase The Analysis Phase The Construction Phase Strengths and Weaknesses The Fusion Method The Unified Modeling Language Summary The Unified Modeling Language Introduction The Meta-Model The Models Use Case Diagrams The Object Model Representing Classes Representing Objects Representing Relationships ' Packages Sequence Diagrams Collaboration Diagrams State Machine Diagrams Start Points Events A Set of Transitions A Set of State Variables A Set of States A Set of Exit Points Deployment Diagrams Summary The Unified Process Introduction The Unified Process Overview of the Unified Process Life Cycle Phases Phases, Iterations and Workflows Workflows and Activities Requirements Workflow 448

14 Contents xxvii Interface Descriptions Analysis Workflow Analysis Model Classes Constructing the Analysis Model Design Workflow Identifying Classes Refining the Set of Classes Identifying and Refining Attributes Identifying and Refining Operations Design Use Case Realizations Generating a Sequence Diagram Building a Statechart Diagram Identifying and Refining Associations Identifying Interfaces and Inheritance Remaining Steps Implementation Workflow Testing Workflow Summary 458 Part 9 The Future 40 Areas of Java and Object Technology not Covered Introduction Language Areas Native Code Java Virtual Machine JavaBeans Enterprise JavaBeans Remote Method Invocation Java and C CORBA Java Naming and Directory Interface Java and XML Java 2D and Java 3D Object-Oriented Databases 469 Appendices A The Java API Packages 471 B Java Keywords 472 References 473 Index 477