README JavaTM 2 SDK, Standard Edition Version 1.3.1

* Disclaimer - this text represents the contents of the README.html file included in Java 2 SDK, Standard Edition, 1.3.1_25.  As these contents are dated, some links may no longer be valid.


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 using the Java programming language.

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 the appletviewer, these tools do not provide a graphical user interface.

Java 2 SDK Documentation

The on-line Java 2 Platform Documentation contains API specifications, feature descriptions, 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 on your machine.

Development Tools

(In the bin subdirectory.) Tools and utilities that will help you develop, execute, debug, and document programs written in the Java programming language.

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, the  Java Virtual Machine Debugger Interface, the Java Virtual Machine Profiler Interface and other functionality of the Java 2 Platform.

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.

The Java 2 Runtime Environment

The Java 2 Runtime Environment is 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 Java platform on which to run your software. It is typically preferable to ship the Java 2 Runtime Environment rather than the Java 2 SDK with your application because the Java 2 Runtime Environment is smaller than the Java 2 SDK.

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 jredirectory. Don't confuse the SDK's internal runtime environment with the Java 2 Runtime Environment, which is a separately installable product.


The term "vendors" used here refers to licensees, developers, and independent software vendors (ISVs) who license and distribute the Java 2 Runtime Environment with their programs. Vendors must follow the terms of the Java 2 SDK, Standard Edition, Binary Code License agreement.

Required vs. Optional Files

The files that make up the Java 2 SDK, Standard Edition, are divided into two categories: required and optional. Optional files may be excluded from redistributions of the Java 2 SDK at the vendor's discretion. The following section contains a list of the files and directories that may optionally be omitted from redistributions of the Java 2 SDK. All files not in these lists of optional files must be included in redistributions of the Java 2 SDK.

Optional Files and Directories

The following files may be optionally excluded from redistributions:


Character conversion classes


Directory containing extension jar files

bin/rmid and jre/bin/rmid

Java RMI Activation System Daemon

bin/rmiregistry and jre/bin/rmiregistry

Java Remote Object Registry

bin/tnameserv and jre/bin/tnameserv

Java IDL Name Server

bin/keytool and jre/bin/keytool

Key and Certificate Management Tool

bin/policytool and jre/bin/policytool

Policy File Creation and Management Tool

bin/orbd and jre/bin/orbd

Object Request Broker Daemon

bin/servertool and jre/bin/servertool

Java IDL Server Tool


Archive of source files

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 web site

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