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<h1><span style="font-size: 90%;">Java^{<font size="-2">TM</font>} 2 Platform

Standard Edition 5.0<br>

Overview</span></h1>

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<a href="../index.html" style="font-size:80%;">Contents</a>

<ul class="SansSerif" style="font-size: 90%;">

<li><a href="#jre-jdk">JRE and JDK</a>

<li><a href="#javalanguage">Java Programming Language</a>

<li><a href="#javavm">Java Virtual Machines</a>

<li><a href="#base">Base Libraries</a>

<li><a href="#integration">Integration Libraries</a>

<li><a href="#userinterface">User Interface Libraries</a>

<li><a href="#deployment">Deployment</a>

<li><a href="#toolspecs">Tool Specifications</a>

<li><a href="#toolsupport">JDK Tools & Utilities</a>

<li><a href="#platforms">Platforms</a>

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<a name="jre-jdk"></a>

<h2>JRE and JDK</h2>

<div class=Indent>

Sun Microsystems provides two principal software products in the

Java^{<font size="-2">TM</font>} 2

Platform Standard Edition (J2SE^{<font size="-2">TM</font>}) family:

<h3>J2SE Runtime Environment (JRE)</h3>

The JRE provides the libraries, Java virtual machine, and other

components necessary for you to <em>run</em> applets and applications

written in the Java programming language. This runtime environment can

be redistributed with applications to make them free-standing.

<h3>J2SE Development Kit (JDK)</h3>

The JDK includes the JRE plus command-line development tools such as

compilers and debuggers that are necessary or useful for <em>developing</em>

applets and applications.

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<a name="javalanguage"></a>

<h2>Java Programming Language</h2>

<div class=Indent>

The Java Programming Language is a general-purpose, concurrent, strongly

typed, class-based object-oriented language. It is normally compiled to

the bytecode instruction set and binary format defined in the Java

Virtual Machine Specification.

For more information see

<a href="language/index.html">Language Features</a>.

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<a name="javavm"></a>

<h2>Java Virtual Machines</h2>

<div class=Indent>

The Java virtual machine is an abstract computing machine that has

an instruction set and manipulates memory at run time.

The Java virtual machine is ported to different platforms to provide

hardware- and operating system-independence.

The Java 2 Platform Standard Edition provides two implementations of the Java virtual

machine (VM):

<h3>Java HotSpot Client VM</h3>

The client VM is an implementation for platforms typically used for

client applications. The client VM is tuned for reducing start-up time and memory

footprint. It can be invoked by using the <code>-client</code> command-line

option when launching an application. </p>

<h3>Java HotSpot Server VM</h3>

The server VM is an implementation designed for maximum program execution speed,

trading off launch time and memory.

It can be invoked by using the <code>-server</code> command-line option

when launching an application.

<p> For more information, see the <a href="vm/index.html">VM documentation</a>.

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<a name="base"></a><a name="core"></a>

<h2>Base Libraries</h2>

<div class=Indent>

<p>Classes and interfaces that provide basic features and fundamental functionality for the Java platform.

</p>

<a name="langutil"></a>

<h3>Lang and Util Packages</h3>

Provides the fundamental <tt>Object</tt> and <tt>Class</tt> classes, wrapper

classes for primitive types, a basic math class, and more. See the <a href="lang/index.html">Lang

and Util documentation</a> for more information.

<b>Math</b>

Math functionality includes floating point libraries and arbitrary-precision

math.

For more information, see the <a href="math/index.html">Math documentation</a>.

<b>Monitoring and Management</b>

Comprehensive monitoring and management support for

Java platform including Monitoring and Management API for

Java virtual machine, Monitoring and Management API for the Logging Facility,

jconsole and other monitoring utilities, out-of-the-box monitoring and management,

Java Management Extensions (JMX), and Sun's Platform Extension.

See the <a href="management/index.html">Monitoring

and Management documentation</a> for more information.

<b>Package Version Identification</b>

The package versioning feature enables package-level version control so that

applications and applets can identify at runtime the version of a specific

Java Runtime Environment, VM, and class package.

For more information, see the <a href="versioning/index.html">Package Version

Identification documentation</a>.

<b>Reference Objects</b>

Reference objects support a limited degree of interaction with the garbage

collector. A program may use a reference object to maintain a reference to

some other object in such a way that the latter object may still be reclaimed

by the collector. A program may also arrange to be notified some time after

the collector has determined that the reachability of a given object has

changed. Reference objects are therefore useful for building simple caches as

well as caches that are flushed when memory runs low, for implementing mappings

that do not prevent their keys (or values) from being reclaimed, and for

scheduling pre-mortem cleanup actions in a more flexible way than is possible

with the Java finalization mechanism.

For more information, see the <a href="nio/index.html">Reference Objects documentation</a>.

<b>Reflection</b>

Reflection enables Java code to discover information about the fields, methods

and constructors of loaded classes, and to use reflected fields,

methods, and constructors to operate on their underlying counterparts

on objects, within security restrictions. The API accommodates

applications that need access to either the public members of a target

object (based on its runtime class) or the members declared by a given class.

Programs can suppress default reflective access control.

For more information, see the <a href="reflection/index.html">Reflection documentation</a>.

<b>Collections Framework</b>

A <em>collection</em> is an object that represents a group of objects.

The collections framework is a unified architecture for representing collections,

allowing them to be manipulated independently of the details of their representation.

It reduces programming effort while increasing performance. It allows for

interoperability among unrelated APIs, reduces effort in designing and learning

new APIs, and fosters software reuse. For more information, see the

<a href="collections/index.html">Collections Framework documentation</a>.

<b>Concurrency Utilities</b>

The Concurrency Utilities packages provide a powerful, extensible framework

of high-performance threading utilities such as thread pools and blocking queues.

This package frees the programmer from the need to craft these utilities by hand,

in much the same manner the Collections Framework did for data structures.

Additionally, these packages provide low-level primitives for advanced

concurrent programming.

For more information, See the <a href="concurrency/index.html">Concurrency

Utilities documentation</a>.

<b>Java Archive (JAR) Files</b>

JAR (Java Archive) is a platform-independent file format that aggregates many

files into one. Multiple Java applets and their requisite components

(.class files, images and sounds) can be bundled in a JAR file and

subsequently downloaded to a browser in a single HTTP transaction,

greatly improving the download speed. The JAR format also supports

compression, which reduces the file size, further improving the download

time. In addition, the applet author can digitally sign individual entries

in a JAR file to authenticate their origin. It is fully extensible.

For more information, see the <a href="jar/index.html">Java Archive documentation</a>.

<b>Logging </b>

The Logging APIs facilitate software servicing and maintenance at

customer sites by producing log reports suitable for analysis by end users,

system administrators, field service engineers, and software development

teams. The Logging APIs capture information such as security failures, configuration

errors, performance bottlenecks, and/or bugs in the application or platform.

For more information, see the <a href="logging/index.html">Logging documentation</a>.

<b>Preferences</b>

The Preferences API provides a way for applications to store and retrieve

user and system preference and configuration data. The data is stored persistently

in an implementation-dependent backing store. There are two separate trees

of preference nodes, one for user preferences and one for system preferences.

For more information, see the <a href="preferences/index.html">Preferences

API documentation</a>,

<a name="otherbase"></a>

<h3>Other Base Packages</h3>

<b>New I/O </b>

The new I/O (NIO) APIs introduced in J2SE 1.4 provide new features and

improved performance in the areas of buffer management, scalable network

and file I/O, character-set support, and regular-expression matching. The

NIO APIs supplement the I/O facilities in the <tt>java.io</tt> package.

For more information, see the <a href="nio/index.html">New I/O documentation</a>.

<b>I/O</b>

I/O functionality provides for system input and output through

data streams, serialization and the file system.

In 1.4, a <a href="nio/index.html">new I/O (NIO) API</a>

was introduced that provides new features and improved performance.

For more information, see the <a href="io/index.html">I/O documentation</a>.

<b>Object Serialization</b>

Object Serialization extends the core Java Input/Output classes with support

for objects. Object Serialization supports the encoding of objects, and the

objects reachable from them, into a stream of bytes; and it supports the

complementary reconstruction of the object graph from the stream. Serialization

is used for lightweight persistence and for communication via sockets or Remote

Method Invocation (RMI). See the <a href="serialization/index.html">Object

Serialization documentation</a> for more information.

<b>Networking</b>

Provides classes for networking functionality, including addressing, classes

for using URLs and URIs, socket classes for connecting to servers, networking

security functionality, and more. See the <a href="net/index.html">Networking

documentation</a> for more information.

<b>Security</b>

APIs for security-related functionality such as configurable access control,

digital signing, authentication and authorization, cryptography, secure

Internet communication, and more. See the <a href="security/index.html">Security

documentation</a> for more information.

<b>Internationalization </b>

APIs that enable the development of internationalized applications.

Internationalization

is the process of designing an application so that it can be adapted to

various languages and regions without engineering changes.

See the <a href="intl/index.html">Internationalization

documentation</a> for more information.

<b>JavaBeans^{<font size="-2">TM</font>} Component API </b>

Contains classes related to developing beans -- components based on the

JavaBeans^{<font size="-2">TM</font>} architecture that can be pieced

together as part of developing an application. See the <a href="beans/index.html">JavaBeans

documentation</a> for more information.

<b>Java Mangement Extensions (JMX)</b>

The Java Management Extensions (JMX) API is a standard API for

management and monitoring of resources such as applications, devices,

services, and the Java virtual machine. Typical uses include

consulting and changing application configuration,

accumulating statistics about application behavior,

and notifying of state changes and erroneous conditions.

The JMX API includes remote access, so a remote management program

can interact with a running application for these purposes.

See the <a href="jmx/index.html">Java Management Extensions

documentation</a> for more information. </p>

<b>XML (JAXP) </b>

The Java platform provides a rich set of APIs for processing XML documents

and data. See the J2SE <a href="xml/index.html">XML documentation</a> for

more information.

<b>Java Native Interface (JNI)</b>

Java Native Interface (JNI) is a standard programming interface for writing

Java native methods and embedding the Java virtual machine into native applications.

The primary goal is binary compatibility of native method libraries across

all Java virtual machine implementations on a given platform. See the

<a href="jni/index.html">Java Native Interface documentation</a> for more information.

<b>Extension Mechanism</b>

Optional packages are packages of Java classes (and any associated native code)

that application developers can use to extend the functionality of the core

platform. The extension mechanism allows the Java virtual machine (VM) to

use the classes of the optional extension in much the same way as the VM

uses classes in the Java 2 Platform. The extension mechanism also provides

a way for needed optional packages to be retrieved from specified URLs when

they are not already installed in the Java 2 SDK or Runtime Environment.

See the <a href="extensions/index.html">Java Extension Mechanism</a>

documentation</a> for more information. </p>

<b>Endorsed Standards Override Mechanism</b>

An endorsed standard is a Java API defined through a standards process other

than the Java Community ProcessSM (JCP). Because endorsed standards are defined

outside the JCP, it is anticipated that such standards may be revised between

releases of the Java 2 Platform. In order to take advantage of new revisions

to endorsed standards, developers and software vendors may use the Endorsed

Standards Override Mechanism to provide newer versions of an endorsed standard

than those included in the Java 2 Platform as released by Sun Microsystems.

See the <a href="standards/index.html">Endorsed Standards Override Mechanism

documentation</a> for more information. </p>

<HR SIZE=3 NOSHADE>

<a name="integration"></a>

<h2>Integration Libraries</h2>

<div class=Indent>

<h3>Java Database Connectivity (JDBC) API</h3>

<p>The JDBC^{<font size="-2">TM</font>} API provides universal data

access from the Java programming language. Using the JDBC 3.0 API, you developers

can write applications that can access virtually any data source, from relational

databases to spreadsheets and flat files. JDBC technology also provides a

common base on which tools and alternate interfaces can be built.

For more information, see the <a href="jdbc/index.html">JDBC documentation</a>.

</p>

<h3>Remote Method Invocation (RMI)</h3>

<p>Remote Method Invocation (RMI) enables the development of distributed applications

by providing for remote communication between programs written in the Java

programming language. RMI enables an object running in one Java Virtual Machine

to invoke methods on an object running in another Java VM, which may be on

a different host.

For more information, see the J2SE <a href="rmi/index.html">RMI documentation</a>.

</p>

<h3>Java IDL (CORBA)</h3>

<p>Java IDL technology adds CORBA (Common Object Request Broker Architecture)

capability to the Java platform, providing standards-based interoperability

and connectivity. Java IDL enables distributed Web-enabled Java applications

to transparently invoke operations on remote network services using the industry

standard IDL (Object Management Group Interface Definition Language) and IIOP

(Internet Inter-ORB Protocol) defined by the Object Management Group. Runtime

components include a Java ORB for distributed computing using IIOP communication.

For more information, see the <a href="idl/index.html">Java IDL

documentation</a>.

</p>

<h3>RMI-IIOP</h3>

<p>Java Remote Method Invocation over Internet Inter-ORB Protocol technology

The RMI Programming Model enables the programming of CORBA servers and applications

via the RMI API. You can choose to work completely within the Java programming

language using the Java Remote Method Protocol (JRMP) as the transport, or work

with other CORBA-compliant programming languages using the Internet InterORB Protocol

(IIOP).

You use the rmic compiler to generate the code necessary for connecting your

applications via the Internet InterORB Protocol (IIOP) to others written in

any CORBA-compliant language. To work with CORBA applications in other languages,

IDL can be generated from Java programming language interfaces using the rmic

compiler with the -idl option. To generate IIOP stubs and tie classes, use the

rmic compiler with the -iiop option.

For more information, see the <a href="rmi-iiop/index.html">RMI-IIOP

documentation</a>.

</p>

<h3>Java Naming and Directory Interface^{<font size="-2">TM</font>}

(JNDI) API</h3>

<p>The Java platform includes a powerful API for capturing, processing, and

playing back audio and MIDI (Musical Intstrument Digital Interface) data.

This API is supported by an efficient sound engine which guarantees high-quality

audio mixing and MIDI synthesis capabilities for the platform.

For more information, see <a href="jndi/index.html">JNDI documentation</a>.

</p>

<HR SIZE=3 NOSHADE>

<a name="userinterface"></a>

<h2>User Interface Libraries</h2>

<div class=Indent>

<h3>Input Method Framework</h3>

<p>The input method framework enables the collaboration between text editing

components and input methods in entering text. Input methods are software

components that let the user enter text in ways other than simple typing on

a keyboard. They are commonly used to enter Japanese, Chinese, or Korean --

languages using thousands of different characters - on keyboards with far

fewer keys. However, the framework also supports input methods for other languages

and the use of entirely different input mechanisms, such as handwriting or

speech recognition.

For more information, see the <a href="imf/index.html">Input Method Framework</a>

documentation. </p>

<h3>Accessibility</h3>

<p>With the Java Accessibility API, developers can easily create Java applications

that are accessible to disabled persons. Accessible Java applications are

compatible with assistive technologies such as screen readers, speech recognition

systems, and refreshable braille displays.

For more information, see the <a href="access/index.html">Accessibility

documentation</a>. </p>

<p>

<h3>Print Service</h3>

<p>The Java^{<font size="-2">TM</font>} Print Service API,

allows printing on all Java platforms including those

requiring a small footprint, such as a J2ME profile.

For more information, see <a href="jps/index.html">Java Print Service documentation</a>.

</p>

<h3>Sound</h3>

<p>The Java platform includes a powerful API for capturing, processing, and

playing back audio and MIDI (Musical Intstrument Digital Interface) data.

This API is supported by an efficient sound engine which guarantees high-quality

audio mixing and MIDI synthesis capabilities for the platform.

For more information, see <a href="sound/index.html">Java Sound documentation</a>.

</p>

<h3>Drag and Drop Data Transfer</h3>

<p>Drag and Drop enables data transfer both across Java programming language

and native applications, between Java programming language applications,

and within a single Java programming language application.

For more information, see <a href="dragndrop/index.html">Drag and Drop Transfer</a>.

</p>

<h3>Image I/O</h3>

<p>The Java Image I/O API provides a pluggable architecture for working with

images stored in files and accessed across the network.

The API provides provides a framework for the addition of format-specific

plugins. Plug-ins for several common formats are included with Java

Image I/O, but third parties can use this API to create their own plugins to

handle special formats.

For more information, see <a href="imageio/index.html">Image I/O</a>.

</p>

<h3>Java 2D^{<font size="-2">TM</font>} Graphics and Imaging</h3>

<p>The Java 2D^{<font size="-2">TM</font>} API is a set of classes for

advanced 2D graphics and imaging. It encompasses line art, text, and images

in a single comprehensive model. The API provides extensive support for image

compositing and alpha channel images, a set of classes to provide accurate

color space definition and conversion, and a rich set of display-oriented

imaging operators.

For more information, see the <a href="2d/index.html">Java 2D documentation</a>.

</p>

<h3>AWT</h3>

<p>The Java^{<font size="-2">TM</font>} platform's Abstract Windowing

Toolkit (AWT) provides APIs for constructing user interface components such

as menus, buttons, text fields, dialog boxes, checkboxes, and for handling

user input through those components. In addition, AWT allows for rendering

of simple shapes such as ovals and polygons and enables developers to control

the user-interface layout and fonts used by their applications.

For more information, see the <a href="awt/index.html">AWT documentation</a>.

</p>

<h3>Swing</h3>

<p> The Swing APIs also provide graphical component (GUI) for use in user interfaces.

The Swing APIs are written in the Java programming language without any reliance

on code that is specific to the GUI facilities provided by underlying operating

system. This allows the Swing GUI components to have a "pluggable" look-and-feel

that can be switched while an application is running.

For more information, see the J2SE <a href="swing/index.html">Swing documentation</a>.

</p>

<HR SIZE=3 NOSHADE>

<a name="deployment"></a>

<h2>Deployment</h2>

<div class=Indent>

<h3>Java Deployment</h3>

Installation, setup, updating, redistribution and related topics:</p>

<ul>

<li>Installation of the Java Platform on a computer</li>

<li>Setting Options in the Java Control Panel</li>

<li>Writing applications and applets in the Java Programming language</li>

<li>Authoring web pages that invoke applets or download and launch applications</li>

<li>Making Java-related files available on web servers</li>

<li>Updating the Java Platform on a computer</li>

</ul>

<p>For more information, see <a href="deployment/index.html">General Deployment</a>,

<a href="plugin/index.html">Java Plug-in</a>, and

<a href="javaws/index.html">Java Web Start</a>.

<HR SIZE=3 NOSHADE>

<a name="toolspecs"></a>

<h2>Tool Specifications</h2>

<div class=Indent>

<h3>Debugger Architecture</h3>

Architecture and specifications for for use by debuggers in

development environments.

For more information, see the <a href="jpda/index.html">Java

Platform Debugger Architecture (JPDA) documentation</a>.

</p>

<h3>VM Tool Interface</h3>

The Java Virtual Machine Tool Interface (JVM TI) is a

specification for inspecting the state and

controlling the execution of applications running in the JVM.

The Java Virtual Machine Profiler Interface (JVMPI) has been deprecated.

For more information, see the <a href="jvmti/index.html">Java

Virtual Machine Tool Interface (JVM TI) documentation</a>.

</p>

<h3>Javadoc Tool</h3>

Javadoc is a tool that parses the declarations and documentation comments

source files to produce a set of HTML pages describing the program elements.

The Doclet API provides a mechanism for clients to inspect the source-level

structure of programs and libraries, including javadoc comments embedded

in the source. This API can be used by doclets to generate documentation.

For more information, see the <a href="javadoc/index.html">Javadoc

documentation</a>.

</p>

<h3>Annotation Processing</h3>

The apt tool is a command-line utility for annotation processing. It includes

a set of reflective APIs and supporting infrastructure to process program

annotations. These reflective APIs provide a build-time, source-based,

read-only view of program structure. They are designed to cleanly model

the Java programming language's type system after the addition of generics.

For more information, see the <a href="apt/index.html">apt documentation</a>.

<HR SIZE=3 NOSHADE>

<a name="toolsupport"></a>

<h2>JDK Tools & Utilities</h2>

<div class=Indent>

<p> Documentation for the tools and utilities included in the JDK.

Covers basic tools (javac, java, javadoc, apt, appletviewer,

jar, jdb, javah, javap, extcheck), security tools, internationalization

tools, RMI tools, IDL and RMI-IIOP tools, deployment tools,

Java Plug-in tools, and Java Web Start tools, monitoring and management

tools, and troubleshooting tools.

For more information, see the

<a href="../tooldocs/index.html">JDK Tools and Utilities</a>

documentation. </p>

<HR SIZE=3 NOSHADE>

<a name="platforms"></a>

<h2>Platforms</h2>

<div class=Indent>

<p>Sun provides implementations of the JDK and Java Runtime Environment

for Microsoft Windows, Linux, and the Solaris operating systems. See

<a href="http://java.sun.com/j2se/1.5.0/system-configurations.html">System

Configurations</a> for information about which

versions of these platforms are supported. </p>

Other companies may provide implementations of the Java platform for other

operating systems such as Macintosh, AIX, etc. </p>

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<FONT SIZE="-2"> <A HREF="../relnotes/SMICopyright.html">Copyright</A>

&#169; 2004 <A HREF="http://www.sun.com/">Sun Microsystems, Inc.</A>

All Rights Reserved.</FONT>

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<TD ALIGN=RIGHT> <IMG SRC="../images/sunlogo64x30.gif" ALT="Sun" BORDER=0 WIDTH=64 HEIGHT=30>

<BR>

<FONT SIZE="+1"> <i>Java Software</i> </FONT> </TD>

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