Java: Rheinwerk Computing

... Preface ... 31

... Target Group ... 31

... What This Book Is Not ... 31

... My Life and Java, Or "Why a Java Book?" ... 32

... Software and Versions ... 33

... Which Java Version to Use ... 33

... Using This Book to Learn ... 33

... Personal Learning Strategies ... 34

... Focusing on the Essentials ... 35

... Special Sections ... 35

... Tasks ... 36

... Structure of This Book ... 36

... Conventions ... 38

... Program Listings ... 40

... Application Programming Interface Documentation in This Book ... 40

... Executable Programs ... 41

... Acknowledgments ... 41

... Resources for This Book ... 42

... Feedback ... 42

1 ... Introduction ... 43

1.1 ... Historical Background ... 43

1.2 ... On the Popularity of Java: The Key Features ... 45

1.3 ... Java versus Other Languages* ... 56

1.4 ... Further Development and Losses ... 59

1.5 ... Java Platforms ... 62

1.6 ... Java Platform, Standard Edition, Implementations ... 67

1.7 ... Installing the Java Development Kit ... 69

1.8 ... Compiling and Testing the First Program ... 71

1.9 ... Development Environments ... 75

1.10 ... Further Reading ... 81

2 ... Imperative Language Concepts ... 83

2.1 ... Elements of the Java Programming Language ... 83

2.2 ... From Classes to Statements ... 91

2.3 ... Data Types, Typing, Variables, and Assignments ... 102

2.4 ... Expressions, Operands, and Operators ... 119

2.5 ... Conditional Statements or Case Distinctions ... 142

2.6 ... Always the Same with Loops ... 160

2.7 ... Methods of a Class ... 177

2.8 ... Further Reading ... 200

3 ... Classes and Objects ... 201

3.1 ... Object-Oriented Programming ... 201

3.2 ... Members of a Class ... 203

3.3 ... Natural Modeling Using Unified Modeling Language* ... 204

3.4 ... Creating New Objects ... 206

3.5 ... ZZZZZnake ... 218

3.6 ... Tying Packages, Imports, and Compilation Units ... 220

3.7 ... Using References, Diversity, Identity, and Equality ... 228

3.8 ... Further Reading ... 239

4 ... Arrays and Their Areas of Use ... 241

4.1 ... Simple Field Work ... 241

4.2 ... The Extended for Loop ... 252

4.3 ... A Method with a Variable Number of Arguments ... 256

4.4 ... Multidimensional Arrays* ... 259

4.5 ... Library Support for Arrays ... 264

4.6 ... Using the Arrays Class for Comparing, Filling, Searching, and Sorting ... 267

4.7 ... The Entry Point for the Runtime System: main(...) ... 281

4.8 ... Further Reading ... 285

5 ... Handling Characters and Strings ... 287

5.1 ... From ASCII via ISO-8859-1 to Unicode ... 287

5.2 ... Data Types for Characters and Strings ... 295

5.3 ... The Character Class ... 296

5.4 ... Strings ... 301

5.5 ... The String Class and Its Methods ... 303

5.6 ... Mutable Strings with StringBuilder and StringBuffer ... 333

5.7 ... CharSequence as Base Type ... 342

5.8 ... Converting Primitives and Strings ... 345

5.9 ... Concatenating Strings ... 353

5.10 ... Decomposing Strings ... 355

5.11 ... Formatting Outputs ... 360

5.12 ... Further Reading ... 367

6 ... Writing Custom Classes ... 369

6.1 ... Declaring Custom Classes with Members ... 369

6.2 ... Privacy and Visibility ... 380

6.3 ... One for All: Static Methods and Class Variables ... 390

6.4 ... Constants and Enumerations ... 397

6.5 ... Creating and Destroying Objects ... 405

6.6 ... Class and Object Initialization* ... 418

6.7 ... Conclusion ... 426

7 ... Object-Oriented Relationship ... 427

7.1 ... Associations between Objects ... 427

7.2 ... Inheritance ... 436

7.3 ... Types in Hierarchies ... 447

7.4 ... Overriding Methods ... 457

7.5 ... Testing Dynamic Bindings ... 463

7.6 ... Final Classes and Final Methods ... 466

7.7 ... Abstract Classes and Abstract Methods ... 468

7.8 ... Further Information on Overriding and Dynamic Binding ... 476

7.9 ... A Programming Task ... 482

8 ... Interfaces, Enumerations, Sealed Classes, Records ... 483

8.1 ... Interfaces ... 483

8.2 ... Enumeration Types ... 513

8.3 ... Sealed Classes and Interfaces ... 523

8.4 ... Records ... 529

9 ... There Must Be Exceptions ... 539

9.1 ... Fencing In Problem Areas ... 539

9.2 ... Redirecting Exceptions and throws at the Head of Methods/Constructors ... 549

9.3 ... The Class Hierarchy of Exceptions ... 550

9.4 ... Final Handling Using finally ... 558

9.5 ... Triggering Custom Exceptions ... 564

9.6 ... try with Resources (Automatic Resource Management) ... 579

9.7 ... Special Features of Exception Handling* ... 588

9.8 ... Hard Errors: Error* ... 593

9.9 ... Assertions* ... 594

9.10 ... Conclusion ... 597

10 ... Nested Types ... 599

10.1 ... Nested Classes, Interfaces, and Enumerations ... 599

10.2 ... Static Nested Types ... 601

10.3 ... Non-Static Nested Types ... 603

10.4 ... Local Classes ... 605

10.5 ... Anonymous Inner Classes ... 607

10.6 ... Nests ... 613

10.7 ... Conclusion ... 614

11 ... Special Types of Java SE ... 615

11.1 ... Object Is the Mother of All Classes ... 616

11.2 ... Weak References and Cleaners ... 638

11.3 ... The java.util.Objects Utility Class ... 639

11.4 ... Comparing Objects and Establishing Order ... 643

11.5 ... Wrapper Classes and Autoboxing ... 651

11.6 ... Iterator, Iterable* ... 670

11.7 ... Annotations in Java Platform, Standard Edition ... 677

11.8 ... Further Reading ... 682

12 ... Generics ... 683

12.1 ... Introduction to Java Generics ... 683

12.2 ... Implementing Generics, Type Erasure, and Raw Types ... 699

12.3 ... Restricting Types via Bounds ... 706

12.4 ... Type Parameters in the throws Clause* ... 710

12.5 ... Inheritance and Invariance with Generics ... 713

12.6 ... Consequences of Type Erasure: Type Tokens, Arrays* ... 725

12.7 ... Further Reading ... 729

13 ... Lambda Expressions and Functional Programming ... 731

13.1 ... Functional Interfaces and Lambda Expressions ... 731

13.2 ... Method References ... 755

13.3 ... Constructor References ... 759

13.4 ... Functional Programming ... 762

13.5 ... Functional Interfaces from the java.util.function Package ... 770

13.6 ... Optional Is Not a Non-Starter ... 784

13.7 ... What Is So Functional Now? ... 795

13.8 ... Further Reading ... 797

14 ... Architecture, Design, and Applied Object Orientation ... 799

14.1 ... SOLID Modeling ... 799

14.2 ... Architecture, Design, and Implementation ... 803

14.3 ... Design Patterns ... 803

14.4 ... Further Reading ... 811

15 ... Java Platform Module System ... 813

15.1 ... Class Loader and Module/Classpath ... 813

15.2 ... Importing Modules ... 819

15.3 ... Developing Custom Modules ... 825

15.4 ... Further Reading ... 833

16 ... The Class Library ... 835

16.1 ... The Java Class Philosophy ... 835

16.2 ... Simple Time Measurement and Profiling* ... 842

16.3 ... The Class Class ... 843

16.4 ... The Utility Classes System and Members ... 846

16.5 ... The Languages of Different Countries ... 853

16.6 ... Overview of Important Date Classes ... 857

16.7 ... Date-Time API ... 860

16.8 ... Logging with Java ... 864

16.9 ... Maven: Resolving Build Management and Dependencies ... 867

16.10 ... Further Reading ... 869

17 ... Introduction to Concurrent Programming ... 871

17.1 ... Concurrency and Parallelism ... 871

17.2 ... Generating Existing Threads and New Threads ... 875

17.3 ... Thread Members and States ... 882

17.4 ... Enter the Executor ... 893

17.5 ... Further Reading ... 907

18 ... Introduction to Data Structures and Algorithms ... 909

18.1 ... Lists ... 909

18.2 ... Sets ... 928

18.3 ... Associative Memory ... 938

18.4 ... The Stream API ... 944

18.5 ... Creating a Stream ... 947

18.6 ... Terminal Operations ... 951

18.7 ... Intermediary Operations ... 962

18.8 ... Further Reading ... 968

19 ... Files and Data Streams ... 969

19.1 ... Old and New Worlds in java.io and java.nio ... 969

19.2 ... File Systems and Paths ... 970

19.3 ... Random Access Files ... 980

19.4 ... Base Classes for Input/Output ... 985

19.5 ... Reading from Files and Writing to Files ... 996

19.6 ... Further Reading ... 1003

20 ... Introduction to Database Management with JDBC ... 1005

20.1 ... Relational Databases and Java Access ... 1005

20.2 ... A Sample Query ... 1008

20.3 ... Further Reading ... 1009

21 ... Bits and Bytes, Mathematics and Money ... 1011

21.1 ... Bits and Bytes ... 1011

21.2 ... Floating Point Arithmetic in Java ... 1025

21.3 ... The Members of the Math Class ... 1031

21.4 ... Accuracy and the Value Range of Type and Overflow Control* ... 1042

21.5 ... Random Numbers: Random, ThreadLocalRandom, and SecureRandom ... 1046

21.6 ... Large Numbers* ... 1051

21.7 ... Money and Currency ... 1064

21.8 ... Further Reading ... 1066

22 ... Testing with JUnit ... 1067

22.1 ... Software Tests ... 1067

22.2 ... The JUnit Testing Framework ... 1068

22.3 ... Java Assertion Libraries and AssertJ ... 1081

22.4 ... Structure of Large Test Cases ... 1083

22.5 ... Good Design Enables Effective Testing ... 1085

22.6 ... Dummy, Fake, Stub, and Mock ... 1087

22.7 ... JUnit Extensions and Testing Add-Ons ... 1089

22.8 ... Further Reading ... 1089

23 ... The Tools of the JDK ... 1091

23.1 ... Overview ... 1091

23.2 ... Translating Java Sources ... 1092

23.3 ... The Java Runtime Environment ... 1093

23.4 ... Documentation Comments with Javadoc ... 1096

23.5 ... The JAR Archive Format ... 1105

23.6 ... Further Reading ... 1107

... The Author ... 1109

... Index ... 1111