README - Java™ Platform, Standard Edition 8 Development Kit - JDK™ 8


Thank you for downloading this release of the Java Platform, Standard Edition Development Kit (JDK). The JDK is a development environment for building applications, applets, and components using the Java programming language.

The JDK includes tools useful for developing and testing programs written in the Java programming language and running on the Java platform.

System Requirements & Installation

System requirements, installation instructions and troubleshooting tips are located on the Java Platform web site at:

Installation Instructions

JDK Documentation

The on-line Java Platform, Standard Edition (Java SE) Documentation contains API specifications, feature descriptions, developer guides, reference pages for JDK tools and utilities, demos, and links to related information. The Java SE documentation is also available in a download bundle which you can install on your machine. To obtain the documentation bundle, see the download page. For API documentation, refer to the The Java Platform, Standard Edition API Specification. This documentation provides brief descriptions of the API with an emphasis on specifications, not on code examples.

Release Notes

See the Release Notes on the Java Platform web site for additional information pertaining to this release. Please check the on-line release notes occasionally for the latest information as they will be updated as needed.


See Compatibility with Previous Releases on the Java Platform web site for the list of known compatibility issues. Every effort has been made to support programs written for previous versions of the Java platform. Although some incompatible changes were necessary, most software should migrate to the 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 web page. Some compatibility-breaking changes were required to close potential security holes or to fix implementation or design bugs.

Bug Reports and Feedback

The JDK Bug Database 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 send feedback to the Java SE documentation team.

Note - Please do not seek technical support through the Bug Database or our development teams. For support options, see Support and Services on Oracle Support web site.

Contents of the JDK

This section contains a general summary of the files and directories in the JDK. For details on the files and directories, see the File Structure section of the Java SE documentation for your platform.

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. For further information, see the tools documentation.

Runtime Environment

(In the jre/ subdirectory) An implementation of the Java Runtime Environment (JRE) for use by the JDK. The JRE includes a Java Virtual Machine (JVM™), 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.

Java DB

(In the db/ subdirectory) Java DB, Oracle's distribution of the Apache Derby relational database. For further information, see the documentation.

C header Files

(In the include/ subdirectory) Header files that support native-code programming using the Java Native Interface, the JVM Tool Interface, and other functionality of the Java platform.

Source Code

(In Java programming language source files for all classes that make up the Java core API (that is, sources files for the java.*, javax.* and some org.* 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 any common zip utility. Or, you may use the Jar utility in the JDK's bin/ directory: jar xvf

JavaFX Tools

Various tools specific to JavaFX are included. Note that the JDK on ARM does not include JavaFX.

JavaFX packaging tool


Documentation for JavaFX packager

man/man1/javafxpackager.1 [Mac OS X, Linux]

man/ja_JP.UTF-8/man1/javafxpackager.1 [Linux]

JavaFX packager ant tasks


JavaFX doclet for javadoc


JavaFX support jar for JMX


The Java™ Runtime Environment (JRE™)

The Java Runtime Environment (JRE) is available as a separately downloadable product. See the download web site.

The JRE allows you to run applications written in the Java programming language. Like the JDK, it contains the Java Virtual Machine (JVM), classes comprising the Java platform API, and supporting files. Unlike the JDK, it does not contain development tools such as compilers and debuggers.

You can freely redistribute the JRE with your application, according to the terms of the JRE license. Once you have developed your application using the JDK, you can ship it with the JRE so your end-users will have a Java platform on which to run your software.


NOTE - The license for this software does not allow the redistribution of beta and other pre-release versions.
Current releases of the Oracle Java SE 8 Development Kit require a commercial license for redistribution. Legacy releases were licensed differently. Please see this FAQ for more information.

You may reproduce and distribute the Software (and also portions of Software identified below as Redistributable), provided that you comply with the terms and conditions of the Oracle Binary Code License Agreement for the Java SE Platform Products.

The term "vendors" used here refers to licensees, developers, and independent software vendors (ISVs) who license and distribute the Java Runtime Environment (JRE) with their programs.

Vendors must follow the terms of the Oracle Binary Code License Agreement for the Java SE Platform Products.

Required vs. Optional Files

The files that make up the Java Runtime Environment (JRE) are divided into two categories: required and optional. Optional files may be excluded from redistributions of the JRE at the vendor's discretion.

On JDK installations, the JRE directory, containing the redistributable portions, is located in the jdk1.8.0_<version>/jre directory, where <version> is the update version number.

Please refer to the JRE Readme for details of which files are required and which files are optional when distributing a JRE.

The JDK includes additional tools that might also be redistributed.

Redistributable JDK Files

The limited set of files and directories from the JDK listed below may be included in vendor redistributions of the Java Runtime Environment (JRE). They cannot be redistributed separately, and must accompany a JRE distribution. All paths are relative to the top-level directory of the JDK. The corresponding man pages should be included for any included executables (with paths listed below beginning with bin/, for the Solaris Operating System and Linux).


Color profile. This file is required only if one wishes to convert between the PYCC color space and another color space.

All .ttf font files in the jre/lib/fonts/ directory.

Note that the LucidaSansRegular.ttf font is already contained in the JRE, so there is no need to bring that file over from the JDK.

The javac bytecode compiler, consisting of the following files:

  • bin/javac [Solaris Operating System (x86) and Linux]
  • bin/sparcv9/javac [Solaris Operating System (SPARC(R) Platform Edition)]
  • bin/amd64/javac [Solaris Operating System (x64)]
  • bin\javac.exe [Microsoft Windows]
  • lib/tools.jar [All platforms]


The Jconsole application.

The dynamic attach mechanism consisting of the following files:

  • lib/tools.jar/ [All platforms]
  • jre/lib/sparcv9/ [Solaris Operating System (SPARC(R) Platform Edition)]
  • jre/lib/i386/ [Linux (x86)]
  • jre/lib/amd64/ [Solaris Operating System (x64) and Linux (x64)]
  • jre\bin\attach.dll [Microsoft Windows]

The dynamic attach mechanism is not available for the JDK on ARM.


On Microsoft Windows platforms, the JDK includes both the Java HotSpot™ Server VM and Java HotSpot™ Client VM. However, the JRE for Microsoft Windows platforms includes only the Java HotSpot™ Client VM. Those wishing to use the Java HotSpot Server VM with the JRE may copy the JDK's jre\bin\server folder to a bin\server directory in the JRE. Software vendors may redistribute the Java HotSpot Server VM with their redistributions of the JRE.


JAR Signing and verification tool.

Archive of source files

Unlimited Strength Java Cryptography Extension

Due to import control restrictions for some countries, the Java Cryptography Extension (JCE) policy files shipped with the JDK and the JRE allow strong but limited cryptography to be used. These files are located at: <java-home>/lib/security/local_policy.jar <java-home>/lib/security/US_export_policy.jar where <java-home> is the jre directory of the JDK or the top-level directory of the JRE.

An unlimited strength version of these files indicating no restrictions on cryptographic strengths is available on the JDK web site for those living in eligible countries. Those living in eligible countries may download the unlimited strength version and replace the strong cryptography jar files with the unlimited strength files.

The cacerts Certificates File

Root CA certificates may be added to or removed from the Java SE certificate file located at:


For more information, see The cacerts Certificates File section in the keytool documentation.

Java Endorsed Standards Override Mechanism

From time to time it is necessary to update the Java platform in order to incorporate newer versions of standards that are created outside of the Java Community ProcessSM (JCPSM ) (Endorsed Standards), or in order to update the version of a technology included in the platform to correspond to a later standalone version of that technology (Standalone Technologies).

The Endorsed Standards Override Mechanism provides a means whereby later versions of classes and interfaces that implement Endorsed Standards or Standalone Technologies may be incorporated into the Java Platform.

For more information on the Endorsed Standards Override Mechanism, including the list of platform packages that it may be used to override, see

Web Pages

For additional information, refer to these Oracle pages on the World Wide Web:

The Java Platform web site, with the latest information on Java technology, product information, news, and features.

Java platform Documentation provides access to white papers, the Java Tutorial and other documents.

Developer Services web site (Free registration required). Additional technical information, news, and features; user forums; support information, and much more.

Java Technology Products & API