JavaTM 2 SDK, Standard Edition
Version 1.3 Release Candidate



Thank you for downloading this release of the JavaTM 2 SDK, Standard Edition. The Java 2 SDK is a development environment for building applications, applets, and components that can be deployed on implementations of the Java 2 Platform.

A Japanese version of this README is on the Java Software web site.

The Java 2 SDK includes tools useful for developing and testing programs written in the Java programming language and running on the Java platform. These tools are designed to be used from the command line. Except for appletviewer, these tools do not provide a graphical user interface.

The Java 2 SDK includes the Java Plug-in. You can use the Java Plug-in to enable the Internet Explorer and Netscape Navigator browsers to run applets based on the Java 2 platform. For more information about the Java Plug-in, see the section Java 2 Runtime Environment and Java Plug-in below.

[web] - This marker, which appears throughout this README file, indicates links to the Java Software website. These markers appear next to links to local copies of the same documents (which are broken links if you do not have the Java 2 SDK documentation installed locally).


Version 1.3 of the Java 2 SDK offers significant improvements in functionality and performance over previous versions. See:

Java 2 SDK Documentation

The on-line Java 2 SDK Documentation [web] contains API specifications, developer guides, reference pages for SDK tools and utilities, demos, and links to related information. This documentation is also available in a download bundle which you can install locally with your Java 2 SDK software. To obtain the documentation bundle, see the Java 2 SDK download page on the Java Developer ConnectionSM web site..

For API documentation, refer to the following sources:

System Requirements

The Java 2 SDK is intended for use on Windows 95, Windows 98, Windows NT 4.0 or Windows 2000 operating systems running on Intel hardware, with the following additional requirements and recommendations:

A Pentium 166MHz or faster processor. At least 32 megabytes of physical RAM is required to run GUI applications. Forty-eight megabytes is recommended for applets running within a browser using the Java Plug-in product. Running with less memory may cause disk swapping which has a severe effect on performance. Very large programs may require more RAM for adequate performance.

You should have 65 megabytes of free disk space before attempting to install the Java 2 SDK software. If you also install the separate documentation download bundle, you need an additional 120 megabytes of free disk space.

The Java 2 SDK is localized for Japanese. For more information, see Japanese localization notes.


The complete Java 2 SDK is composed of the SDK software plus the SDK documentation, each of which is separately downloadable. Installation instructions for each release are maintained on the Java Software web site.

Release Notes

See the Release Notes on the Java Software web site for additional information pertaining to this release. The on-line release notes will be updated as needed, so you should check it occasionally for the latest information.


See Compatibility with Previous Releases on the Java Software web site for the list of known compatibility issues. Every effort has been made to support programs written for previous version of the Java platform. Although some incompatible changes were necessary, most software should migrate to current version with no reprogramming. Any failure to do so is considered a bug, except for a small number of cases where compatibility was deliberately broken, as described on our compatibility page. Some compatibility-breaking changes were required to close potential security holes or to fix implementation or design bugs.

Bug Reports and Feedback

The Bug Parade Web Page on the Java Developer Connection web site lets you search for and examine existing bug reports, submit your own bug reports, and tell us which bug fixes matter most to you. To directly submit a bug or request a feature, fill out this form:
You can also send comments directly to Java Software engineering team email addresses.

Note - You should not seek technical support from Bug Parade or our development teams. For support options, see Support and Services on the Java Software web site.

Contents of the Java 2 SDK

This section contains a general summary of the files and directories in the Java 2 SDK. For details on the files and directories, see Java 2 SDK File Structure [web].
Development Tools
(In the bin subdirectory.) Programs that will help you develop, execute, debug, and document programs written in the Java programming language. For further information, see the tool documentation [web].

Runtime Environment
(In the jre subdirectory.) An implementation of the Java 2 runtime environment for use by the SDK. The runtime environment includes a Java virtual machine, class libraries, and other files that support the execution of programs written in the Java programming language.

Additional libraries
(In the lib subdirectory.) Additional class libraries and support files required by the development tools.

Demo Applets and Applications
(In the demo subdirectory.) Examples, with source code, of programming for the Java platform. These include examples that use Swing and other Java Foundation Classes, and the Java Platform Debugger Architecture.

C header Files
(In the include subdirectory.) Header files that support native-code programming using the Java Native Interface [web] and the Java Virtual Machine Debugger Interface [web].

Old Native Interface Headers
(In the include-old subdirectory.) Header files that support native-code programming using older interfaces. The header files in include-old are provided only for backward-compatibility. These interfaces are deprecated, unsupported and not available on all Java virtual machines.

Source Code
(In src.jar archive file.) Java programming language source files for all classes that make up the Java 2 core API (that is, sources files for the java.*, javax.* and org.omg.* packages, but not for com.sun.* packages). This source code is provided for informational purposes only, to help developers learn and use the Java programming language. These files do not include platform-specific implementation code and cannot be used to rebuild the class libraries. To extract these file, use this command:
    jar xvf src.jar

Do not modify core API source files. To extend the behavior of the core API, write subclasses of the core API classes.

For API documentation, refer to the following sources:

  • The Java Platform API Specification [web]. This provides brief descriptions of the API with an emphasis on specifications, not on examples.

  • The Java Class Libraries, Second Edition, published by Addison-Wesley Longman as part of The Java Series. These volumes include much more elaborate descriptions, with definitions of terminology and examples for practically every class, interface and member.

(In the docs subdirectory.) This directory is created when the Java 2 SDK documentation is installed. It contains release documentation, API specifications, developer guides, tool documentation, demos, and links to related documentation.

The Java 2 Runtime Environment and Java Plug-in

The download bundle for the Java 2 SDK includes a copy of the Java 2 Runtime Environment and Java Plug-in. The Java 2 Runtime Environment and Java Plug-in are also available as a separately downloadable product.

The Java 2 Runtime Environment allows you to run applications written in the Java programming language. Like the Java 2 SDK, it contains the Java virtual machine, classes comprising the Java 2 Platform API, and supporting files. Unlike the Java 2 SDK, it does not contain development tools such as compilers and debuggers.

You can freely redistribute the Java 2 Runtime Environment with your application, according to the terms of the Runtime Environment's license. Once you have developed your application using the Java 2 SDK, you can ship it with the Runtime Environment so your end-users will have a 1.3-based Java platform on which to run your software.

Note that the Java 2 SDK has an internal implementation of a Java runtime environment for its own use. This internal runtime environment is contained in the SDK's jre directory. Don't confuse the SDK's internal runtime environment with the Java 2 Runtime Environment, which is a separately installable product.

The Java 2 Runtime Environment requires additional software -- the Java Plug-in software -- to enable it to run applets in a browser. The Win32 version of the Java 2 Runtime Environment includes the Java 2 Plug-in software.

The Java Plug-in software allows Java applets and JavaBeans components to run in a browser using Sun's Java 2 Runtime Environment instead of the browser's default Java environment. The Java Plug-in works with Netscape Navigator and Microsoft Internet Explorer. For documentation and an FAQ on the Java Plug-in, see Java Plug-in.

After the plug-in is installed, you will see that the "Java Plug-in control panel" has been added to your Windows "Start" menu under "Programs". The plug-in will automatically load the Java runtime environment when the browser loads an HTML page with a special <OBJECT> HTML tag. The browser can then load applets from this page to make full use of 1.3 features. For details on how to configure your HTML pages to invoke the Java 2 runtime environment, see "Documentation" at Sun's Java Plug-in website.

Sun Java Web Pages

For additional information, refer to these Sun Microsystems pages on the World Wide Web:
The Java Software web site, with the latest information on Java technology, product information, news, and features.
Java 2 SDK Product and Download Page
Java Platform Documentation provides access to white papers, the Java Tutorial and other documents.
The Java Developer Connection web site. (Free registration required.) Additional technical information, news, and features; user forums; support information, and much more.
Java Technology Products & API
Java Platform Technologies for the SolarisTM Operating Environment

The Java 2 SDK, Standard Edition, is a product of Sun MicrosystemsTM, Inc.

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