Contents
Hide sidebar ❮❯ Show sidebar
Module java.base
module java.base
Defines the foundational APIs of the Java SE Platform.
- Providers:
- The JDK implementation of this module provides an implementation of
the jrt file system provider to enumerate and read the class and resource
files in a run-time image.
The jrt file system can be created by calling
FileSystems.getFileSystem(URI.create("jrt:/")).
- Module Graph:
[Module graph for java.base]- Tool Guides:
- java launcher, keytool
- Since:
- 9
![[Module graph for java.base]](https://docs.oracle.com/en/java/javase/24/docs/api/java.base/java/lang/../../module-graph.svg){kind=link}
-
Packages
ExportsPackageDescriptionProvides for system input and output through data streams, serialization and the file system.Provides classes that are fundamental to the design of the Java programming language.Provides library support for the Java programming language annotation facility.Provides classfile parsing, generation, and transformation library.Provides interfaces describingclassfile attributes for thejava.lang.classfilelibrary.Provides interfaces describing constant pool entries for thejava.lang.classfilelibrary.Provides interfaces describing code instructions for thejava.lang.classfilelibrary.Classes and interfaces to represent nominal descriptors for run-time entities such as classes or method handles, and classfile entities such as constant pool entries orinvokedynamiccall sites.Provides low-level access to memory and functions outside the Java runtime.Thejava.lang.invokepackage provides low-level primitives for interacting with the Java Virtual Machine.Classes to support module descriptors and creating configurations of modules by means of resolution and service binding.Provides reference-object classes, which support a limited degree of interaction with the garbage collector.Provides classes and interfaces for obtaining reflective information about classes and objects.Thejava.lang.runtimepackage provides low-level runtime support for the Java language.Provides classes for performing arbitrary-precision integer arithmetic (BigInteger) and arbitrary-precision decimal arithmetic (BigDecimal).Provides the classes for implementing networking applications.Service-provider classes for thejava.netpackage.Defines buffers, which are containers for data, and provides an overview of the other NIO packages.Defines channels, which represent connections to entities that are capable of performing I/O operations, such as files and sockets; defines selectors, for multiplexed, non-blocking I/O operations.Service-provider classes for thejava.nio.channelspackage.Defines charsets, decoders, and encoders, for translating between bytes and Unicode characters.Service-provider classes for thejava.nio.charsetpackage.Defines interfaces and classes for the Java virtual machine to access files, file attributes, and file systems.Interfaces and classes providing access to file and file system attributes.Service-provider classes for thejava.nio.filepackage.Provides the classes and interfaces for the security framework.Provides classes and interfaces for parsing and managing certificates, certificate revocation lists (CRLs), and certification paths.Provides interfaces for generating RSA (Rivest, Shamir and Adleman AsymmetricCipher algorithm) keys as defined in the RSA Laboratory Technical Note PKCS#1, and DSA (Digital Signature Algorithm) keys as defined in NIST's FIPS-186.Provides classes and interfaces for key specifications and algorithm parameter specifications.Provides classes and interfaces for handling text, dates, numbers, and messages in a manner independent of natural languages.Service provider classes for the classes in the java.text package.The main API for dates, times, instants, and durations.Generic API for calendar systems other than the default ISO.Provides classes to print and parse dates and times.Access to date and time using fields and units, and date time adjusters.Support for time-zones and their rules.Contains the collections framework, some internationalization support classes, a service loader, properties, random number generation, string parsing and scanning classes, base64 encoding and decoding, a bit array, and several miscellaneous utility classes.Utility classes commonly useful in concurrent programming.A small toolkit of classes that support lock-free thread-safe programming on single variables.Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.Functional interfaces provide target types for lambda expressions and method references.Provides classes for reading and writing the JAR (Java ARchive) file format, which is based on the standard ZIP file format with an optional manifest file.This package contains classes and interfaces that support a generic API for random number generation.Classes for matching character sequences against patterns specified by regular expressions.Service provider classes for the classes in the java.util package.Classes to support functional-style operations on streams of elements, such as map-reduce transformations on collections.Provides classes for reading and writing the standard ZIP and GZIP file formats.Provides the classes and interfaces for cryptographic operations.Provides interfaces for Diffie-Hellman keys as defined in RSA Laboratories' PKCS #3.Provides classes and interfaces for key specifications and algorithm parameter specifications.Provides classes for networking applications.Provides classes for the secure socket package.This package provides a framework for authentication and authorization.This package provides the classes necessary for services to interact with applications in order to retrieve information (authentication data including usernames or passwords, for example) or to display information (error and warning messages, for example).This package provides a pluggable authentication framework.This package provides the interface to be used for implementing pluggable authentication modules.This package contains the classes that should be used to store X500 Principal and X500 Private Credentials in a Subject.Provides classes for public key certificates. -
Services
ProvidesUsesTypeDescriptionAn abstract implementation of a calendar system, used to organize and identify dates.Service-provider class for asynchronous channels.An abstract class for service providers that provide concrete implementations of theBreakIteratorclass.An abstract class for service providers that provide locale-dependentCalendarparameters.An abstract class for service providers that provide localized string representations (display names) ofCalendarfield values.Charset service-provider class.A calendar system, used to organize and identify dates.An abstract class for service providers that provide concrete implementations of theCollatorclass.This interface defines a factory for content handlers.An abstract class for service providers that provide localized currency symbols and display names for theCurrencyclass.An abstract class for service providers that provide concrete implementations of theDateFormatclass.An abstract class for service providers that provide instances of theDateFormatSymbolsclass.An abstract class for service providers that provide instances of theDecimalFormatSymbolsclass.Service-provider class for file systems.A file type detector for probing a file to guess its file type.An abstract class for service providers that provide localized names for theLocaleclass.Service-provider interface for authentication technology providers.An abstract class for service providers that provide concrete implementations of theNumberFormatclass.This class represents a "provider" for the Java Security API, where a provider implements some or all parts of Java Security.An interface for service providers that provide implementations ofResourceBundle.Control.ResourceBundleProvideris a service provider interface for resource bundles.Service-provider class for selectors and selectable channels.TheLoggerFinderservice is responsible for creating, managing, and configuring loggers to the underlying framework it uses.An abstract class for service providers that provide localized time zone names for theTimeZoneclass.An interface for command-line tools to provide a way to be invoked without necessarily starting a new VM.URL stream handler service-provider class.Provider of time-zone rules to the system.
Report a bug or suggest an enhancement
For further API reference and developer documentation see the Java SE Documentation, which contains more detailed, developer-targeted descriptions with conceptual overviews, definitions of terms, workarounds, and working code examples. Other versions.
Java is a trademark or registered trademark of Oracle and/or its affiliates in the US and other countries.
Copyright © 1993, 2025, Oracle and/or its affiliates, 500 Oracle Parkway, Redwood Shores, CA 94065 USA.
All rights reserved. Use is subject to license terms and the documentation redistribution policy.