Foundations of object orientation

Transcription

1 Foreword Preface List of projects discussed in detail in this book Acknowledgments Part 1 Chapter 1 Chapter 2 Foundations of object orientation Objects and classes 1.1 Objects and classes 1.2 Creating objects 1.3 Calling methods 1.4 Parameters 1.5 Data types 1.6 Multiple instances 1.7 State 1.8 What is in an object? 1.9 Java code 1.10 Object interaction 1.11 Source code 1.12 Another example 1.13 Return values 1.14 Objects as parameters 1.15 Summary Understanding class definitions 2.1 Ticket machines Exploring the behavior of a naive ticket machir xiii xiv xxiii xxv Examining a class definition The class header Keywords Fields, constructors, and methods Fields Constructors Parameters: receiving data Choosing variable names Assignment Methods Accessor and mutator methods Printing from methods Method summary Summary of the naive ticket machine Reflecting on the design of the ticket machine Making choices: the conditional statement A further conditional-statement example Scope highlighting Local variables Fields, parameters, and local variables Summary of the better ticket machine Self-review exercises Reviewing a familiar example Calling methods 54

2 2.22 Experimenting with expressions: the Code Pad Summary 58 Chapter 3 Object interaction The clock example Abstraction and modularization Abstraction in software Modularization in the clock example Implementing the clock display Class diagrams versus object diagrams Primitive types and object types The Cl ockdi spl ay source code Class NumberDi spl ay String concatenation The modulo operator Class Cl ockdi spl ay Objects creating objects Multiple constructors Method calls Internal method calls External method calls Summary of the clock display Another example of object interaction The mail-system example The th is keyword Using a debugger Setting breakpoints Single stepping Stepping into methods Method calling revisited Summary 89 Chapter 4 Grouping objects Building on themes from Chapter The collection abstraction An organizer for music files Using a library class Importing a library class Diamond notation Key methods of ArrayLi st Object structures with collections Generic classes Numbering within collections The effect of removal on numbering The general utility of numbering with collections Playing the music files Summary of the music organizer Processing a whole collection The for-each loop Selective processing of a collection A limitation of using strings Summary of the for-each loop Indefinite iteration The while loop Iterating with an index variable Searching a collection Some non-collection examples Improving structure the Track class The Iterator type Index access versus iterators Removing elements Summary of the music-organizer project 126

3 Chapter Another example: An auction system Getting started with the project The n u ll keyword The Lot class The A ucti on class Anonymous objects Chaining method calls Using collections Flexible-collection summary Fixed-size collections A log-file analyzer Declaring array variables Creating array objects Using array objects Analyzing the log file The for loop Arrays and the for-each loop The for loop and iterators Summary 150 More-sophisticated behavior Documentation for library classes The TechSupport system Exploring the TechSupport system Reading the code Reading class documentation Interfaces versus implementation ,3.2 Using library-class methods Checking string equality Adding random behavior The Random class Random numbers with limited range Generating random responses Reading documentation for parameterized classes Packages and import Using maps for associations The concept of a map Using a HashMap Using a map for the TechSupport system Using sets Dividing strings Finishing the TechSupport system Writing class documentation Using javadoc in BlueJ Elements of class documentation Public versus private Information hiding Private methods and public fields Learning about classes from their interfaces The scribble demo Code completion The bouncing-balls demo Class variables and constants The s ta tic keyword Constants Summary 193 Chapter 6 Designing classes Introduction The world-of-zuul game example Introduction to coupling and cohesion Code duplication 201

4 6.5 Making extensions Unit testing within BlueJ The task ,1 Using inspectors Finding the relevant 7.3,2 Positive versus negative source code 205 testing Coupling 6,6.1 Using encapsulation to Test automation Regression testing reduce coupling Automated testing using 6.7 Responsibility-driven JUnit 246 design Recording a test Responsibilities and Fixtures 251 coupling Debugging Localizing change Commenting and style Implicit coupling Manual walkthroughs Thinking ahead A high-level 6.11 Cohesion 219 walkthrough Cohesion of methods Checking state with a Cohesion of classes 220 walkthrough Cohesion for Verbal walkthroughs 260 readability Print statements Cohesion for reuse Turning debugging 6.12 Refactoring 222 information on or off Refactoring and 7.9 Debuggers 263 testing Choosing a debugging An example of strategy 265 refactoring Putting the techniques 6.13 Refactoring for language into practice 265 independence Summary Enumerated types Further decoupling of the command Part 2 Application structures 267 interface Design guidelines 231 Chapter 8 Improving structure with 6.15 Executing without BlueJ 232 inheritance Class methods The main method The network example Limitations in class methods Summary The network project: classes and objects Network source code Discussion of the Chapter 7 Well-behaved objects 236 network application introduction Using inheritance Testing and debugging Inheritance hierarchies

5 8.4 Inheritance in Java 285 Chapter 10 Further abstraction Inheritance and access techniques 326 rights Simulations Inheritance and 10.2 The foxes-and-rabbits initialization 286 simulation Network: adding other post The foxes-and-rabbits types 288 project Advantages of inheritance The Rabbit class 331 (so far) The Fox class Subtyping The Si mul a to r class: Subclasses and setup 337 subtypes ,2.5 The Si mul a to r class: Subtyping and a simulation step 341 assignment Taking steps to Subtyping and improve the parameter passing 295 simulation Polymorphic variables Abstract classes Casting The Animal 8.8 The O bject class 297 superclass Autoboxing and wrapper Abstract methods 344 classes Abstract classes The collection hierarchy More abstract methods Summary Multiple inheritance An A ctor class 351 Chapter 9 More about inheritance Flexibility through 9.1 The problem: network s display abstraction 353 method Selective drawing Static type and dynamic type Drawable actors: Calling di spl ay from multiple inheritance 354 NewsFeed Interfaces Overriding An A ctor interface Dynamic method lookup Multiple inheritance of 9.5 Super call in methods 311 interfaces Method polymorphism Interfaces as types Object methods: to S trin g Interfaces as specifications Object equality: equal s and hashcode Library support through abstract 9.9 Protected access 318 classes and 9.10 The i nstanceof operator 320 interfaces Another example of 10.7 A further example of inheritance with overriding 321 interfaces Summary The Class class 361

6 Chapter Abstract class or interface? Event-driven simulations Summary of inheritance Summary 364 Building graphical user interfaces Introduction Components, layout, and event handling AWT and Swing The ImageViewer example First experiments: creating a frame Adding simple components An alternative structure Adding menus Event handling Centralized receipt of events Inner classes Anonymous inner classes Summary of key GUI elements ImageViewer 1.0: the first complete version Image-processing classes Adding the image Layout Nested containers Image filters Dialogs Summary of layout management ImageViewer 2.0: improving program structure ImageViewer 3.0: more interface components Buttons Borders Further extensions Another example: MusicPlayer Summary 411 Chapter 12 Handling errors The address-book project Defensive programming Client-server interaction ,2.2 Parameter checking Server-error reporting Notifying the user Notifying the client object Exception-throwing principles Throwing an exception Checked and unchecked exceptions The effect of an exception Using unchecked exceptions Preventing object creation Exception handling Checked exceptions: the throws clause Anticipating exceptions: the try statement Throwing and catching multiple exceptions Multi-catch Java Propagating an exception The finally clause Defining new exception classes Using assertions Internal consistency checks 440

7 The assert statement Guidelines for using assertions Assertions and the BlueJ unit testing framework Error recovery and avoidance Error recovery Error avoidance File-based input/output Readers, writers, and streams The File class and Path interface File output The try-with-resource statement Text input Scanner: parsing input Object serialization Summary 458 Chapter 13 Designing applications Analysis and design The verb/noun method The cinema booking example Discovering classes Using CRC cards Scenarios Class design Designing class interfaces User interface design Documentation Cooperation Prototyping Software growth Waterfall model Iterative development Using design patterns Structure of a pattern Decorator Singleton Factory method Observer Pattern summary Summary 478 Chapter 14 A case study The case study The problem description Analysis and design Discovering classes Using CRC cards Scenarios Class design Designing class interfaces Collaborators The outline implementation Testing Some remaining issues Iterative development Development steps A first stage Testing the first stage A later stage of development Further ideas for development Reuse Another example Taking things further 499 Appendices A Working with a BlueJ project 500 B Java data types 503

8 C Operators 507 D Java control structures 510 E Running Java without BlueJ 517 F Using the debugger 520 G Unit unit-testing tools 524 H Teamwork tools 526 I Javadoc 528 J Program style guide 531 K Important library classes 535 Index 539