Table 5-1. Key packages of the Java platform
|
Package
|
Description
|
|---|
|
java.io
|
Classes and interfaces for input and
output. Although some of the classes in this package are for working
directly with files, most are for working with streams of bytes or
characters.
|
|
java.lang
|
The core classes of the
language, such as String, Math,
System, THRead, and
Exception.
|
|
java.lang.annotation
|
Annotation types and other supporting types for the Java 5.0
annotation feature. (See Chapter 4.)
|
|
java.lang.instrument
|
Support classes for Java virtual machine instrumentation
agents, which are
allowed to modify the byte code of the program the JVM is running.
New in Java 5.0.
|
|
java.lang.management
|
A framework for monitoring and managing a running Java virtual
machine. New in Java 5.0.
|
|
java.lang.ref
|
Classes that define weak references
to objects. A weak reference is one that does not prevent the
referent object from being garbage-collected.
|
|
java.lang.reflect
|
Classes and interfaces that allow Java
programs to reflect on themselves by examining the constructors,
methods, and fields of classes.
|
|
java.math
|
A small package that contains
classes for arbitrary-precision integer and floating-point
arithmetic.
|
|
java.net
|
Classes and interfaces for networking with
other systems.
|
|
java.nio
|
Buffer classes for the New I/O API. Added in Java 1.4.
|
|
java.nio.channels
|
Channel and selector interfaces and
classes for high-performance, nonblocking I/O.
|
|
java.nio.charset
|
Character set
encoders and decoders for converting Unicode strings to and from
bytes.
|
|
java.security
|
Classes and interfaces for access
control and authentication. This package and its subpackages support
cryptographic message digests and digital signatures.
|
|
java.text
|
Classes
and interfaces for working with text in internationalized
applications.
|
|
java.util
|
Various utility classes, including the
powerful collections framework for working with collections of
objects.
|
|
java.util.concurrent
|
Thread pools and other utility classes for concurrent programming.
Subpackages support atomic variables and locks. New in Java
5.0.
|
|
java.util.jar
|
Classes
for reading and writing JAR files.
|
|
java.util.logging
|
A flexible logging facility. Added in
Java 1.4.
|
|
java.util.prefs
|
An API to read and write user and system
preferences. Added in Java 1.4.
|
|
java.util.regex
|
Text pattern matching using regular
expressions. Added in Java 1.4.
|
|
java.util.zip
|
Classes for reading and writing ZIP files.
|
|
javax.crypto
|
Classes
and interfaces for encryption and decryption of data.
|
|
javax.net
|
Defines factory classes for
creating sockets and server sockets. Enables the creation of socket
types other than the default.
|
|
javax.net.ssl
|
Classes for encrypted network
communication using the Secure Sockets Layer (SSL).
|
|
javax.security.auth
|
The top-level package for the JAAS API
for authentication and authorization. Various subpackages hold most
of the actual classes. Added in Java 1.4.
|
|
javax.xml.parsers
|
A high-level API for parsing XML
documents using pluggable DOM and SAX parsers.
|
|
javax.xml.transform
|
A high-level API for transforming XML
documents using a pluggable XSLT transformation engine and for
converting XML documents between streams, DOM trees, and SAX events.
Subpackages provide support for DOM, SAX and stream transformations.
Added in Java 1.4.
|
