The Java Language Specification, Java SE 7 Edition

James Gosling is the creator of the Java programming language and a former Fellow at Sun Microsystems. He developed the original Java compiler and Java Virtual Machine, and was a principal in the Andrew project at Carnegie Mellon University, where he earned a Ph.D. in Computer Science. He joined Liquid Robotics as Chief Software Architect in 2011.   Bill Joy is a co-founder of Sun Microsystems and was the principal architect of the Berkeley version of UNIX®, for which he received a lifetime achievement award from the USENIX Association in 1993. Joy has had a central role in shaping the Java programming language. He joined KPCB as a Greentech Partner in 2005.   Guy L. Steele Jr. is a Software Architect at Oracle Labs, where he conducts research in language design and implementation strategies, parallel algorithms, and computer arithmetic. Steele is a co-creator of the Scheme programming language, an ACM Fellow, an IEEE Fellow, and a member of the National Academy of Engineering.   Gilad Bracha is the creator of the Newspeak programming language and a former Distinguished Engineer at Sun Microsystems. Prior to Sun, he worked on Strongtalk, the Animorphic Smalltalk System. He holds a Ph.D. in Computer Science from the University of Utah.   Alex Buckley is the Specification Lead for the Java programming language and the Java Virtual Machine at Oracle. He holds a Ph.D. in Computing from Imperial College London.

Preface to the Java SE 7 Edition xvii Preface to the Third Edition xix

Preface to the Second Edition xxiii

Preface to the First Edition xxv



 

Chapter 1: Introduction 1

1.1 Organization of the Specification 2

1.2 Example Programs 5

1.3 Notation 6

1.4 Relationship to Predefined Classes and Interfaces 6

1.5 References 7

 

Chapter 2: Grammars 9

2.1 Context-Free Grammars 9

2.2 The Lexical Grammar 9

2.3 The Syntactic Grammar 10

2.4 Grammar Notation 10

 

Chapter 3: Lexical Structure 15

3.1 Unicode 15

3.2 Lexical Translations 16

3.3 Unicode Escapes 17

3.4 Line Terminators 18

3.5 Input Elements and Tokens 19

3.6 White Space 21

3.7 Comments 21

3.8 Identifiers 23

3.9 Keywords 24

3.10 Literals 25

3.11 Separators 40

3.12 Operators 40

 

Chapter 4: Types, Values, and Variables 41

4.1 The Kinds of Types and Values 41

4.2 Primitive Types and Values 42

4.3 Reference Types and Values 52

4.4 Type Variables 58

4.5 Parameterized Types 60

4.6 Type Erasure 65

4.7 Reifiable Types 66

4.8 Raw Types 67

4.9 Intersection Types 71

4.10 Subtyping 72

4.11 Where Types Are Used 74

4.12 Variables 75

 

Chapter 5: Conversions and Promotions 85

5.1 Kinds of Conversion 88

5.2 Assignment Conversion 101

5.3 Method Invocation Conversion 106

5.4 String Conversion 108

5.5 Casting Conversion 108

5.6 Numeric Promotions 117

 

Chapter 6: Names 121

6.1 Declarations 122

6.2 Names and Identifiers 127

6.3 Scope of a Declaration 130

6.4 Shadowing and Obscuring 133

6.5 Determining the Meaning of a Name 140

6.6 Access Control 152

6.7 Fully Qualified Names and Canonical Names 159

 

Chapter 7: Packages 163

7.1 Package Members 163

7.2 Host Support for Packages 165

7.3 Compilation Units 167

7.4 Package Declarations 168

7.5 Import Declarations 170

7.6 Top Level Type Declarations 175

 

Chapter 8: Classes 179

8.1 Class Declarations 181

8.2 Class Members 196

8.3 Field Declarations 201

8.4 Method Declarations 215

8.5 Member Type Declarations 242

8.6 Instance Initializers 243

8.7 Static Initializers 243

8.8 Constructor Declarations 244

8.9 Enums 253

 

Chapter 9: Interfaces 263

9.1 Interface Declarations 264

9.2 Interface Members 268

9.3 Field (Constant) Declarations 269

9.4 Abstract Method Declarations 271

9.5 Member Type Declarations 274

9.6 Annotation Types 275

9.7 Annotations 285

 

Chapter 10: Arrays 291

10.1 Array Types 292

10.2 Array Variables 292

10.3 Array Creation 294

10.4 Array Access 294

10.5 Array Store Exception 295

10.6 Array Initializers 297

10.7 Array Members 298

10.8 Class Objects for Arrays 300

10.9 An Array of Characters is Not a String 301

 

Chapter 11: Exceptions 303

11.1 The Kinds and Causes of Exceptions 304

11.2 Compile-Time Checking of Exceptions 306

11.3 Run-Time Handling of an Exception 311

 

Chapter 12: Execution 315

12.1 Java Virtual Machine Startup 315

12.2 Loading of Classes and Interfaces 318

12.3 Linking of Classes and Interfaces 320

12.4 Initialization of Classes and Interfaces 322

12.5 Creation of New Class Instances 327

12.6 Finalization of Class Instances 331

12.7 Unloading of Classes and Interfaces 335

12.8 Program Exit 336

 

Chapter 13: Binary Compatibility 337

13.1 The Form of a Binary 338

13.2 What Binary Compatibility Is and Is Not 343

13.3 Evolution of Packages 344

13.4 Evolution of Classes 344

13.5 Evolution of Interfaces 361

 

Chapter 14: Blocks and Statements 365

14.1 Normal and Abrupt Completion of Statements 365

14.2 Blocks 367

14.3 Local Class Declarations 367

14.4 Local Variable Declaration Statements 369

14.5 Statements 371

14.6 The Empty Statement 373

14.7 Labeled Statements 373

14.8 Expression Statements 374

14.9 The if Statement 375

14.10 The assert Statement 376

14.11 The switch Statement 379

14.12 The while Statement 383

14.13 The do Statement 385

14.14 The for Statement 387

14.15 The break Statement 392

14.16 The continue Statement 394

14.17 The return Statement 396

14.18 The throw Statement 397

14.19 The synchronized Statement 399

14.20 The try statement 400

14.21 Unreachable Statements 411

 

Chapter 15: Expressions 417

15.1 Evaluation, Denotation, and Result 417

15.2 Variables as Values 418

15.3 Type of an Expression 418

15.4 FP-strict Expressions 419

15.5 Expressions and Run-Time Checks 419

15.6 Normal and Abrupt Completion of Evaluation 421

15.7 Evaluation Order 423

15.8 Primary Expressions 428

15.9 Class Instance Creation Expressions 432

15.10 Array Creation Expressions 442

15.11 Field Access Expressions 446

15.12 Method Invocation Expressions 451

15.13 Array Access Expressions 490

15.14 Postfix Expressions 493

15.15 Unary Operators 495

15.16 Cast Expressions 499

15.17 Multiplicative Operators 500

15.18 Additive Operators 506

15.19 Shift Operators 511

15.20 Relational Operators 512

15.21 Equality Operators 514

15.22 Bitwise and Logical Operators 517

15.23 Conditional-And Operator 519

15.24 Conditional-Or Operator 520

15.25 Conditional Operator 521

15.26 Assignment Operators 523

15.27 Expression 535

15.28 Constant Expressions 536

 

Chapter 16: Definite Assignment 539

16.1 Definite Assignment and Expressions 545

16.2 Definite Assignment and Statements 549

16.3 Definite Assignment and Parameters 558

16.4 Definite Assignment and Array Initializers 558

16.5 Definite Assignment and Enum Constants 559

16.6 Definite Assignment and Anonymous Classes 559

16.7 Definite Assignment and Member Types 559

16.8 Definite Assignment and Static Initializers 560

16.9 Definite Assignment, Constructors, and Instance Initializers 560

 

Chapter 17:  Threads and Locks 563

17.1 Synchronization 564

17.2 Wait Sets and Notification 564

17.3 Sleep and Yield 568

17.4 Memory Model 569

17.5 final Field Semantics 584

17.6 Word Tearing 589

17.7 Non-atomic Treatment of double and long 590

 

Chapter 18: Syntax 591

 

Index 607



A Limited License Grant 641