book

Java in a Nutshell, 7th Edition

by Benjamin J. Evans, David Flanagan

December 2018

Intermediate to advanced

458 pages

12h 18m

English

O'Reilly Media, Inc.

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Changes in the Seventh EditionContents of This BookRelated BooksExamples OnlineConventions Used in This BookRequest for CommentsO’Reilly SafariAcknowledgments
The Language, the JVM, and the EcosystemWhat Is the Java Language?What Is the JVM?What Is the Java Ecosystem?A Brief History of Java and the JVMThe Lifecycle of a Java ProgramFrequently Asked QuestionsJava SecurityComparing Java to Other LanguagesJava Compared to CJava Compared to C++Java Compared to PythonJava Compared to JavaScriptAnswering Some Criticisms of JavaOverly VerboseSlow to ChangePerformance ProblemsInsecureToo Corporate
Java Programs from the Top DownLexical StructureThe Unicode Character SetCase Sensitivity and WhitespaceCommentsReserved WordsIdentifiersLiteralsPunctuationPrimitive Data TypesThe boolean TypeThe char TypeInteger TypesFloating-Point TypesPrimitive Type ConversionsExpressions and OperatorsOperator SummaryArithmetic OperatorsString Concatenation OperatorIncrement and Decrement OperatorsComparison OperatorsBoolean OperatorsBitwise and Shift OperatorsAssignment OperatorsThe Conditional OperatorThe instanceof OperatorSpecial OperatorsStatementsExpression StatementsCompound StatementsThe Empty StatementLabeled StatementsLocal Variable Declaration StatementsThe if/else StatementThe switch StatementThe while StatementThe do StatementThe for StatementThe foreach StatementThe break StatementThe continue StatementThe return StatementThe synchronized StatementThe throw StatementThe try/catch/finally StatementThe try-with-resources StatementThe assert StatementMethodsDefining MethodsMethod ModifiersChecked and Unchecked ExceptionsVariable-Length Argument ListsIntroduction to Classes and ObjectsDefining a ClassCreating an ObjectUsing an ObjectObject LiteralsLambda ExpressionsArraysArray TypesCreating and Initializing ArraysUsing ArraysMultidimensional ArraysReference TypesReference Versus Primitive TypesManipulating Objects and Reference CopiesComparing ObjectsBoxing and Unboxing ConversionsPackages and the Java NamespacePackage DeclarationGlobally Unique Package NamesImporting TypesImporting Static MembersJava Source File StructureDefining and Running Java ProgramsSummary
Overview of ClassesBasic OO DefinitionsOther Reference TypesClass Definition SyntaxFields and MethodsField Declaration SyntaxClass FieldsClass MethodsInstance FieldsInstance MethodsHow the this Reference WorksCreating and Initializing ObjectsDefining a ConstructorDefining Multiple ConstructorsInvoking One Constructor from AnotherField Defaults and InitializersSubclasses and InheritanceExtending a ClassSuperclasses, Object, and the Class HierarchySubclass ConstructorsConstructor Chaining and the Default ConstructorHiding Superclass FieldsOverriding Superclass MethodsData Hiding and EncapsulationAccess ControlData Accessor MethodsAbstract Classes and MethodsReference Type ConversionsModifier Summary
InterfacesDefining an InterfaceExtending InterfacesImplementing an InterfaceDefault MethodsMarker InterfacesJava GenericsIntroduction to GenericsGeneric Types and Type ParametersDiamond SyntaxType ErasureBounded Type ParametersIntroducing CovarianceWildcardsGeneric MethodsCompile and Runtime TypingUsing and Designing Generic TypesEnums and AnnotationsEnumsAnnotationsDefining Custom AnnotationsType AnnotationsLambda ExpressionsLambda Expression ConversionMethod ReferencesFunctional ProgrammingLexical Scoping and Local VariablesNested TypesStatic Member TypesNonstatic Member ClassesLocal ClassesAnonymous ClassesNon-Denotable Types and varSummary
Java ValuesImportant Methods of java.lang.ObjecttoString()equals()hashCode()Comparable::compareTo()clone()Aspects of Object-Oriented DesignConstantsInterfaces Versus Abstract ClassesCan Default Methods Be Used as Traits?Instance Methods or Class Methods?Composition Versus InheritanceField Inheritance and AccessorsSingletonObject-Oriented Design with LambdasLambdas Versus Nested ClassesLambdas Versus Method ReferencesExceptions and Exception HandlingSafe Java Programming
Basic Concepts of Java Memory ManagementMemory Leaks in JavaIntroducing Mark-and-SweepThe Basic Mark-and-Sweep AlgorithmHow the JVM Optimizes Garbage CollectionEvacuationThe HotSpot HeapOther CollectorsParallelOldFinalizationFinalization DetailsJava’s Support for ConcurrencyThread LifecycleVisibility and MutabilityExclusion and Protecting StatevolatileUseful Methods of ThreadDeprecated Methods of ThreadWorking with ThreadsSummary

Naming and Capitalization ConventionsPractical NamingJava Documentation CommentsStructure of a Doc CommentDoc-Comment TagsInline Doc-Comment TagsCross-References in Doc CommentsDoc Comments for PackagesDocletsConventions for Portable Programs
Introduction to Collections APIThe Collection InterfaceThe Set InterfaceThe List InterfaceThe Map InterfaceThe Queue and BlockingQueue InterfacesAdding Elements to QueuesRemoving Elements from QueuesUtility MethodsArrays and Helper MethodsJava Streams and Lambda ExpressionsFunctional ApproachesThe Streams APISummary
TextSpecial Syntax for StringsString ImmutabilityRegular ExpressionsNumbers and MathHow Java Represents Integer TypesJava and Floating-Point NumbersJava’s Standard Library of Mathematical FunctionsJava 8 Date and TimeIntroducing the Java 8 Date and Time APIQueriesAdjustersLegacy Date and TimeSummary
Classic Java I/OFilesStreamsReaders and Writerstry-with-resources RevisitedProblems with Classic I/OModern Java I/OFilesPathNIO Channels and BuffersByteBufferMapped Byte BuffersAsync I/OFuture-Based StyleCallback-Based StyleWatch Services and Directory SearchingNetworkingHTTPTCPIP
Class Files, Class Objects, and MetadataExamples of Class ObjectsClass Objects and MetadataPhases of ClassloadingLoadingVerificationPreparation and ResolutionInitializationSecure Programming and ClassloadingApplied ClassloadingClassloader HierarchyReflectionWhen to Use ReflectionHow to Use ReflectionDynamic ProxiesMethod HandlesMethodTypeMethod LookupInvoking Method Handles
Why Modules?Modularizing the JDKWriting Your Own ModulesBasic Modules SyntaxBuilding a Simple Modular ApplicationThe Module PathAutomatic ModulesOpen ModulesServicesMulti-Release JARsConverting to a Multi-Release JARMigrating to ModulesCustom Runtime ImagesIssues with ModulesUnsafe and Related ProblemsLack of VersioningSlow Adoption RatesSummary
Command-Line ToolsIntroduction to JShellSummary
Introduction to NashornNon-Java Languages on the JVMMotivationExecuting JavaScript with NashornRunning from the Command LineUsing the Nashorn ShellNashorn and javax.scriptIntroducing javax.script with NashornAdvanced NashornCalling Java from NashornNashorn’s JavaScript Language ExtensionsUnder the HoodThe Future of Nashorn and GraalVMVisualVM

Content preview from Java in a Nutshell, 7th Edition

Chapter 1. Introduction to the Java Environment

Welcome to Java 11.

That version number probably surprises you as much as it does us. It seems like only yesterday that Java 5 was the new thing, and yet here we are, 14 years and 6 major versions later.

You may be coming to the Java ecosystem from another language, or maybe this is your first programming language. Whatever road you may have traveled to get here, welcome—we’re glad you’ve arrived.

Java is a powerful, general-purpose programming environment. It is one of the most widely used programming languages in the world, and has been exceptionally successful in business and enterprise computing.

In this chapter, we’ll set the scene by describing the Java language (which programmers write their applications in), the Java Virtual Machine (which executes those applications), and the Java ecosystem (which provides a lot of the value of the programming environment to development teams).

We’ll briefly cover the history of the Java language and virtual machine, before moving on to discuss the lifecycle of a Java program and clear up some common questions about the differences between Java and other environments.

At the end of the chapter, we’ll introduce Java security, and discuss some of the aspects of Java that relate to secure coding.

The Language, the JVM, and the Ecosystem

The Java programming environment has been around since the late 1990s. It comprises the Java language, and the supporting runtime, otherwise known as the Java ...