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Java Pocket Guide, 4th Edition

by Robert Liguori, Patricia Liguori

August 2017

Intermediate to advanced

290 pages

4h 10m

English

O'Reilly Media, Inc.

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Book StructureConventions Used in This BookO’Reilly SafariHow to Contact UsAcknowledgments
AcronymsAnnotation NamesClass NamesConstant NamesEnumeration NamesGeneric Type Parameter NamesInstance and Static Variable NamesInterface NamesMethod NamesPackage NamesModule NamesParameter and Local Variable Names
Unicode and ASCIIPrintable ASCII CharactersNonprintable ASCII CharactersCompact StringsCommentsKeywordsIdentifiersSeparatorsOperatorsLiteralsBoolean LiteralsCharacter LiteralsInteger LiteralsFloating-Point LiteralsString LiteralsNull LiteralsEscape SequencesUnicode Currency Symbols
Primitive TypesLiterals for Primitive TypesFloating-Point EntitiesOperations Involving Special EntitiesNumeric Promotion of Primitive TypesUnary Numeric PromotionBinary Numeric PromotionSpecial Cases for Conditional OperatorsWrapper ClassesAutoboxing and UnboxingAutoboxingUnboxing
Comparing Reference Types to Primitive TypesDefault ValuesInstance and Local Variable ObjectsArraysConversion of Reference TypesWidening ConversionsNarrowing ConversionsConverting Between Primitives and Reference TypesPassing Reference Types into MethodsComparing Reference TypesUsing the Equality OperatorsUsing the equals() MethodComparing StringsComparing EnumerationsCopying Reference TypesCopying a Reference to an ObjectCloning ObjectsMemory Allocation and Garbage Collection of Reference Types
Classes and ObjectsClass SyntaxInstantiating a Class (Creating an Object)Data Members and MethodsAccessing Data Members and Methods in ObjectsOverloadingOverridingConstructorsSuperclasses and SubclassesThe this KeywordVariable-Length Argument ListsAbstract Classes and Abstract MethodsAbstract ClassesAbstract MethodsStatic Data Members, Static Methods, Static Constants, and Static InitializersStatic Data MembersStatic MethodsStatic ConstantsStatic InitializersInterfacesEnumerationsAnnotation TypesBuilt-in AnnotationsDeveloper-Defined AnnotationsFunctional Interfaces
Expression StatementsEmpty StatementBlocksConditional StatementsThe if StatementThe if else StatementThe if else if StatementThe switch StatementIteration StatementsThe for LoopThe Enhanced for LoopThe while LoopThe do while LoopTransfer of ControlThe break StatementThe continue StatementThe return StatementSynchronized StatementAssert StatementException Handling Statements
The Exception HierarchyChecked/Unchecked Exceptions and ErrorsChecked ExceptionsUnchecked ExceptionsErrorsCommon Checked/Unchecked Exceptions and ErrorsCommon Checked ExceptionsCommon Unchecked ExceptionsCommon ErrorsException Handling KeywordsThe throw KeywordThe try/catch/finally KeywordsThe try-catch StatementThe try-finally StatementThe try-catch-finally StatementThe try-with-resources StatementThe multi-catch ClauseThe Exception Handling ProcessDefining Your Own Exception ClassPrinting Information About ExceptionsThe getMessage() MethodThe toString() MethodThe printStackTrace() Method
Access ModifiersOther (Nonaccess) ModifiersModifiers Encoding

Common Java SE API LibrariesLanguage and Utility LibrariesBase LibrariesIntegration LibrariesMiscellaneous User Interface LibrariesJavaFX User Interface LibraryRemote Method Invocation (RMI) and CORBA LibrariesSecurity LibrariesExtensible Markup Language (XML) Libraries
Java Runtime EnvironmentJava Development KitJava Program StructureCommand-Line ToolsJava CompilerJava InterpreterJava Program PackagerJAR File ExecutionClasspath
Garbage CollectorsSerial CollectorParallel CollectorParallel Compacting CollectorConcurrent Mark-Sweep CollectorGarbage-First (G1) CollectorMemory Management ToolsCommand-Line OptionsResizing the JVM HeapMetaspaceInterfacing with the GCExplicit Garbage CollectionFinalization
Standard Streams in, out, and errClass Hierarchy for Basic Input and OutputFile Reading and WritingReading Character Data from a FileReading Binary Data from a FileWriting Character Data to a FileWriting Binary Data to a FileSocket Reading and WritingReading Character Data from a SocketReading Binary Data from a SocketWriting Character Data to a SocketWriting Binary Data to a SocketSerializationSerializeDeserializeZipping and Unzipping FilesCompressing and Uncompressing GZIP Files
The Path InterfaceThe Files ClassAdditional Features
Creating ThreadsExtending the Thread ClassImplementing the Runnable InterfaceThread StatesThread PrioritiesCommon MethodsSynchronizationConcurrent UtilitiesExecutorsConcurrent CollectionsSynchronizersTiming Utility
The Collection InterfaceImplementationsCollection Framework MethodsCollections Class AlgorithmsAlgorithm EfficienciesComparator Functional InterfaceConvenience Factory Methods
Generic Classes and InterfacesConstructors with GenericsSubstitution PrincipleType Parameters, Wildcards, and BoundsThe Get and Put PrincipleGeneric SpecializationGeneric Methods in Raw Types
Scripting LanguagesScript Engine ImplementationsEmbedding Scripts into JavaInvoking Methods of Scripting LanguagesAccessing and Controlling Java Resources from ScriptsSetting Up Scripting Languages and EnginesScripting Language SetupScripting Engine SetupScripting Engine Validation
Legacy InteroperabilityRegional CalendarsISO CalendarMachine InterfaceDurations and PeriodsJDBC and XSD MappingFormatting
λEs BasicsλEs Syntax and ExampleMethod and Constructor ReferencesSpecific-Purpose Functional InterfacesGeneral-Purpose Functional InterfacesResources for λEsTutorialsCommunity Resources
Getting StartedSnippetsModifiersFlow Control StatementsPackage DeclarationsUsing JShellPrimary ExpressionsDependenciesStatements and Code BlocksMethod and Class DeclarationsViewing, Deleting, and Modifying SnippetsSaving, Loading, and StateJShell FeaturesScratch VariablesTab Auto-CompleteForward ReferencingChecked ExceptionsHierarchy and ScopeSummary of JShell Commands
Project JigsawJava ModulesAutomatic ModulesUnnamed ModulesAccessibilityCompiling ModulesModular JDKjdepsIdentifying DependenciesIdentifying Undocumented JDK Internal DependenciesDefining a ModuleExporting a PackageDeclaring DependenciesTransitive DependenciesDefining Service ProvidersDefining Service APIImplementing Service APIUsing Service Providersjlink
Development, CM, and Test ToolsLibrariesIntegrated Development EnvironmentsWeb Application PlatformsScripting Languages Compatible with JSR-223
Class DiagramsNameAttributesOperationsVisibilityObject DiagramsGraphical Icon RepresentationClasses, Abstract Classes, and InterfacesNotesPackagesConnectorsMultiplicity IndicatorsRole NamesClass RelationshipsAssociationDirect AssociationComposition AssociationAggregation AssociationTemporary AssociationGeneralizationRealizationSequence DiagramsParticipant (1)Found Message (2)Synchronous Message (3)Return Call (4)Asynchronous Message (5)Message to Self (6)Lifeline (7)Activation Bar (8)

Content preview from Java Pocket Guide, 4th Edition

Chapter 21. Java Module System

Java 9 introduces the Project Jigsaw, which both adds modularization to the platform and modularizes the JDK itself. The goal of Jigsaw is twofold: to enable reliable configuration and add strong encapsulation to Java. With modularization, it is now possible to restrict which packages are public and also ensure that runtime dependencies are present when an application is launched.

The Java Platform Module System (JPMS) is implemented as a separate layer within the JVM. This distinguishes it from other module systems, such as OSGi, which are implemented using Classloaders. JPMS enables modularization of the JDK itself.

Project Jigsaw

Project Jigsaw is made up of a JSR (Java Specification Request) and multiple JEPs (JDK Enhancement Proposals). The specifications that make up Jigsaw are as follows:

JSR 376 Java Platform Module System
JEP 200: Modular JDK
JEP 201: Modular Source Code
JEP 220: Modular Runtime Images
JEP 260: Encapsulate Most Internal APIs
JEP 261: Module System
JEP 282: jlink: Java Linker

The main project page for Jigsaw has links to each of these specifications.

Java Modules

Java modules are a JAR file containing a module-info.java file in the default package. Since “module-info” is an invalid Java class name, it is ignored by Java 8 and earlier. It does get compiled to bytecode and is available via reflection. The module file declares the name of the module, dependencies of a module, and which packages are exported ...