PROGRAM DEVELOPMENT IN JAVA: ABSTRACTIONPDF电子书下载

1 Introduction 1

1.1 Decomposition and Abstraction 2

1.2 Abstraction 4

1.2.1 Abstraction by Parameterization 7

1.2.2 Abstraction by Specification 8

1.2.3 Kinds of Abstractions 10

1.3 The Remainder of the Book 12

Exercises 13

2 Understanding Objects in Java 15

2.1 Program Structure 15

2.2 Packages 17

2.3 Objects and Variables 18

2.3.1 Mutability 21

2.3.2 Method Call Semantics 22

2.4 Type Checking 24

2.4.1 Type Hierarchy 24

2.4.2 Conversions and Overloading 27

2.5 Dispatching 29

2.6 Types 30

2.6.1 Primitive Object Types 30

2.6.2 Vectors 31

2.7 Stream Input/Output 32

2.8 Java Applications 33

Exercises 35

3 Procedural Abstraction 39

3.1 The Benefits of Abstraction 40

3.2 Specifications 42

3.3 Specifications of Procedural Abstractions 43

3.4 Implementing Procedures 47

3.5 Designing Procedural Abstractions 50

3.6 Summary 55

Exercises 56

4 Exceptions 57

4.1 Specifications 59

4.2 The Java Exception Mechanism 61

4.2.1 Exception Types 61

4.2.2 Defining Exception Types 62

4.2.3 Throwing Exceptions 64

4.2.4 Handling Exceptions 65

4.2.5 Coping with Unchecked Exceptions 66

4.3 Programming with Exceptions 67

4.3.1 Reflecting and Masking 67

4.4 Design Issues 68

4.4.1 When to Use Exceptions 70

4.4.2 Checked versus Unchecked Exceptions 70

4.5 Defensive Programming 72

4.6 Summary 74

Exercises 75

5 Data Abstraction 77

5.1 Specifications for Data Abstractions 79

5.1.1 Specification of IntSet 80

5.1.2 The Poly Abstraction 83

5.2 Using Data Abstractions 85

5.3 Implementing Data Abstractions 86

5.3.1 Implementing Data Abstractions in Java 87

5.3.2 Implementation of IntSet 87

5.3.3 Implementation of Poly 89

5.3.4 Records 90

5.4 Additional Methods 94

5.5 Aids to Understanding Implementations 99

5.5.1 The Abstraction Function 99

5.5.2 The Representation Invariant 102

5.5.3 Implementing the Abstraction Function and Rep Invariant 105

5.5.4 Discussion 107

5.6 Properties of Data Abstraction Implementations 108

5.6.1 Benevolent Side Effects 108

5.6.2 Exposing the Rep 111

5.7 Reasoning about Data Abstractions 112

5.7.1 Preserving the Rep Invariant 113

5.7.2 Reasoning about Operations 114

5.7.3 Reasoning at the Abstract Level 115

5.8 Design Issues 116

5.8.1 Mutability 116

5.8.2 Operation Categories 117

5.8.3 Adequacy 118

5.9 Locality and Modifiability 120

5.10 Summary 121

Exercises 121

6 Iteration Abstraction 125

6.1 Iteration in Java 128

6.2 Specifying Iterators 130

6.3 Using Iterators 132

6.4 Implementing Iterators 134

6.5 Rep Invariants and Abstraction Functions for Generators 137

6.6 Ordered Lists 138

6.7 Design Issues 143

6.8 Summary 144

Exercises 144

7 Type Hierarchy 147

7.1 Assignment and Dispatching 149

7.1.1 Assignment 149

7.1.2 Dispatching 150

7.2 Defining a Type Hierarchy 152

7.3 Defining Hierarchies in Java 152

7.4 A Simple Example 154

7.5 Exception Types 161

7.6 Abstract Classes 161

7.7 Interfaces 166

7.8 Multiple Implementations 167

7.8.1 Lists 168

7.8.2 Polynomials 171

7.9 The Meaning of Subtypes 174

7.9.1 The Methods Rule 176

7.9.2 The Properties Rule 179

7.9.3 Equality 182

7.10 Discussion of Type Hierarchy 183

7.11 Summary 184

Exercises 186

8 Polymorphic Abstractions 189

8.1 Polymorphic Data Abstractions 190

8.2 Using Polymorphic Data Abstractions 193

8.3 Equality Revisited 193

8.4 Additional Methods 195

8.5 More Flexibility 198

8.6 Polymorphic Procedures 202

8.7 Summary 202

Exercises 204

9 Specifications 207

9.1 Specifications and Specificand Sets 207

9.2 Some Criteria for Specifications 208

9.2.1 Restrictiveness 208

9.2.2 Generality 211

9.2.3 Clarity 212

9.3 Why Specifications? 215

9.4 Summary 217

Exercises 219

10 Testing and Debugging 221

10.1 Testing 222

10.1.1 Black-Box Testing 223

10.1.2 Glass-Box Testing 227

10.2 Testing Procedures 230

10.3 Testing Iterators 231

10.4 Testing Data Abstractions 232

10.5 Testing Polymorphic Abstractions 235

10.6 Testing a Type Hierarchy 235

10.7 Unit and Integration Testing 237

10.8 Tools for Testing 239

10.9 Debugging 242

10.10 Defensive Programming 249

10.11 Summary 251

Exercises 252

11 Requirements Analysis 255

11.1 The Software Life Cycle 255

11.2 Requirements Analysis Overview 259

11.3 The Stock Tracker 264

11.4 Summary 269

Exercises 270

12 Requirements Specifications 271

12.1 Data Models 272

12.1.1 Subsets 273

12.1.2 Relations 274

12.1.3 Textual Information 278

12.2 Requirements Specifications 282

12.3 Requirements Specification for Stock Tracker 286

12.3.1 The Data Model 286

12.3.2 Stock Tracker Specification 289

12.4 Requirements Specification for a Search Engine 291

12.5 Summary 298

Exercises 298

13 Design 301

13.1 An Overview of the Design Process 301

13.2 The Design Notebook 304

13.2.1 The Introductory Section 304

13.2.2 The Abstraction Sections 308

13.3 The Structure of Interactive Programs 310

13.4 Starting the Design 315

13.5 Discussion of the Method 323

13.6 Continuing the Design 324

13.7 The Query Abstraction 326

13.8 The WordTable Abstraction 332

13.9 Finishing Up 333

13.10 Interaction between FP and UI 334

13.11 Module Dependency Diagrams versus DataModels 336

13.12 Review and Discussion 338

13.12.1 Inventing Helpers 339

13.12.2 Specifying Helpers 340

13.12.3 Continuing the Design 341

13.12.4 The Design Notebook 342

13.13 Top-Down Design 343

13.14 Summary 344

Exercises 345

14 Between Design and Implementation 347

14.1 Evaluating a Design 347

14.1.1 Correctness and Performance 348

14.1.2 Structure 353

14.2 Ordering the Program Development Process 360

14.3 Summary 366

Exercises 367

15 Design Patterns 369

15.1 Hiding Object Creation 371

15.2 Neat Hacks 375

15.2.1 Flyweights 375

15.2.2 Singletons 378

15.2.3 The State Pattern 382

15.3 The Bridge Pattern 385

15.4 Procedures Should Be Objects Too 386

15.5 Composites 390

15.5.1 Traversing the Tree 393

15.6 The Power of Indirection 399

15.7 Publish/Subscribe 402

15.7.1 Abstracting Control 403

15.8 Summary 406

Exercises 407

Glossary 409

Index 427