The java.lang.* and java.util.* Packages

The java.lang and java.util packages provide basic functionality that is used by almost all applications. Other packages with names that begin with java.lang and java.util provide supplemental APIs for specific features.

Package List

Package Enhancements More Information
java.lang
Provides classes that are fundamental to the design of the Java programming language such as String, Math, and basic runtime support for threads and processes.

J2SE 5.0,
J2SDK 1.4, and
J2SDK 1.3
java.lang.annotation
Provides library support for the Java programming language annotation facility.

New in J2SE 5.0
java.lang.instrument
Provides services that allow Java programming language agents to instrument programs running on the JVM.

Java SE 6 and
J2SE 5.0
java.lang.management
Provides the management interface for monitoring and management of the JVM as well as the operating system on which the JVM is running.

Java SE 6
java.lang.ref
Provides reference-object classes, which support a limited degree of interaction with the garbage collector.
New in J2SDK 1.3
java.lang.reflect
Provides classes and interfaces for obtaining reflective information about classes and objects.

Java SE 6,
J2SE 5.0, and
J2SDK 1.4
java.util
Provides the collections framework, formatted printing and scanning, array manipulation utilities, event model, date and time facilities, internationalization, and miscellaneous utility classes.

Java SE 6,
J2SE 5.0, and
J2SDK 1.3
java.util.concurrent
java.util.concurrent.atomic
java.util.concurrent.locks
Provides utility classes used in concurrent programming, including support for atomic updates of single variables and a locking framework which supplements language-level synchronization.

New in J2SE 5.0
java.util.jar
java.util.zip
Provides classes for reading and writing the standard ZIP and GZIP file formats as well as the JAR (Java ARchive) file format, which is based on the standard ZIP file format with an optional manifest file.

Java SE 6 and
J2SDK 1.3
java.util.logging
Provides support to maintain and service software at customer sites.

J2SE 5.0 and
J2SDK 1.4
java.util.regex
Provides classes for matching character sequences against patterns specified by regular expressions.

New in J2SDK 1.4
java.util.prefs
Provides classes to store and retrieve user and system preference and configuration data.

J2SDK 1.4
java.util.spi
Service provider classes for the java.util package.

New in Java SE 6

Tutorials and Programmer's Guides

API Enhancements


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