The Core Java API Packages

The Core Java API Packages

At the time of this writing, Table 30-1 lists all of the core API packages defined by Java (those in the java namespace) and summarizes their functions.

Package  :-   Primary Function

java.applet  :-   Supports construction of applets.

java.awt  :-   Provides capabilities for graphical user interfaces.

java.awt.color  :-   Supports color spaces and profiles.

  :-  

java.awt.datatransfer  :-   Transfers data to and from the system clipboard.

java.awt.dnd  :-   Supports drag-and-drop operations.

java.awt.event  :-   Handles events.

java.awt.font  :-   Represents various types of fonts.

java.awt.geom  :-   Allows you to work with geometric shapes.

java.awt.im  :-   Allows input of Japanese, Chinese, and Korean characters to text editing components.

java.awt.im.spi  :-   Supports alternative input devices.

java.awt.image  :-   Processes images.

java.awt.image.renderable  :-     :-   Supports rendering-independent images.

java.awt.print  :-   Supports general print capabilities.

java.beans  :-   Allows you to build software components.

java.beans.beancontext    :-   Provides an execution environment for Beans.

java.io  :-   Inputs and outputs data.

java.lang  :-   Provides core functionality.

java.lang.annotation  :-    Supports annotations (metadata).

java.lang.instrument   :-   Supports program instrumentation.

java.lang.invoke   :-   Supports dynamic languages.

java.lang.management  :-    Supports management of the execution environment.

java.lang.ref  :-   Enables some interaction with the garbage collector.

java.lang.reflect  :-    Analyzes code at run time.

java.math  :-   Handles large integers and decimal numbers.

java.net  :-   Supports networking.

java.nio  :-   Top-level package for the NIO classes. Encapsulates buffers.

java.nio.channels   :-   Encapsulates channels, which are used by the NIO system.

java.nio.channels.spi   :-   Supports service providers for channels.

java.nio.charset  :-   Encapsulates character sets.

java.nio.charset.spi  :-   Supports service providers for character sets.

java.nio.file  :-   Provides NIO support for files.

java.nio.file.attribute:-   Supports NIO file attributes.

java.nio.file.spi  :-   Supports NIO service providers for files.

java.rmi  :-   Provides remote method invocation.

java.rmi.activation  :-    Activates persistent objects.

java.rmi.dgc  :-   Manages distributed garbage collection.

java.rmi.registry  :- Maps names to remote object references.

java.rmi.server  :-   Supports remote method invocation.

java.security  :-   Handles certificates, keys, digests, signatures, and other security functions.

java.security.acl  :-   Manages access control lists.

java.security.cert  :-   Parses and manages certificates.

java.security.interfaces  :-   Defines interfaces for DSA (Digital Signature Algorithm) keys.

java.security.spec  :-   Specifies keys and algorithm parameters.

java.sql  :-   Communicates with a SQL (Structured Query Language) database.

java.text  :-   Formats, searches, and manipulates text.

java.text.spi  :-   Supports service providers for text formatting classes in java.text.

java.time  :-   Primary support for the new date and time API. (Added by JDK 8.)

java.time.chrono  :-   Supports alternative, non-Gregorian calendars. (Added by JDK 8.)

java.time.format  :-   Supports date and time formatting. (Added by JDK 8.)

java.time.temporal  :-   Supports extended date and time functionality. (Added by JDK 8.)

java.time.zone  :-   Supports time zones. (Added by JDK 8.)

java.util  :-   Contains common utilities.

java.util.concurrent  :-   Supports the concurrent utilities.

java.util.concurrent.atomic  :-   Supports atomic (that is, indivisible) operations on variables without the use of locks.

java.util.concurrent.locks  :-   Supports synchronization locks.

java.util.function  :-   Provides several functional interfaces. (Added by JDK 8.)

java.util.jar  :-   Creates and reads JAR files.

java.util.logging  :-   Supports logging of information related to a program’s execution.

java.util.prefs  :-   Encapsulates information relating to user preference.

java.util.regex  :-   Supports regular expression processing.

java.util.spi  :-   Supports service providers for the utility classes in java.util.

java.util.stream  :-   Supports the new stream API. (Added by JDK 8.)

java.util.zip  :-   Reads and writes compressed and uncompressed ZIP files.

Table 30-1   The Core Java API Packages