Oracle Java SE Embedded 8 Update 231 Readme

Thank you for choosing Oracle Java SE Embedded 8u231 for your embedded system. Oracle Java SE Embedded 8 is based on the Java Runtime Environment (JRE) and provides specific features and support for embedded systems.

This document provides details about Oracle Java SE Embedded 8. The Java Runtime Environment contains the Java virtual machine, runtime class libraries, and Java application launcher, which are necessary to run programs written in the Java programming language. It is not a development environment and does not contain development tools such as compilers or debuggers. For development tools, see the Java Development Kit (JDK) Tools and Utilities documentation.

Other documentation for Oracle Java SE Embedded 8:

See also the JDK 8 Update Release Notes for release information on the JDK 8 platform.

Contents

Installation Notes

Before you install, make sure the following is true:

  • You have installed a supported version of the Java SE Development Kit (JDK) or the Java Runtime Environment (JRE).
  • The JDK or JRE directory is searched before any other Java installation on the host. You can use the PATH environment variable or another method, such as a symbolic link.
  • The JAVA_HOME environment variable names the same JDK or JRE directory.

The Oracle Java SE Embedded technology can be installed as follows.

  1. On your host computer, download the Oracle Java SE Embedded bundle from http://www.oracle.com/java/technologies/javase-embedded-downloads.html.
  2. Extract the bundle from the tar file. The following example assumes the bundle was downloaded to the download directory. 
    

$ cd download
$ gunzip *.gz
$ tar -xvf *.tar

    The directory ejdk1.8.0_<version> will be created in your current directory.

  3. Set the EJDK_HOME environment variable to download/ejdk1.8.0_<version>.
  4. Verify the installation by displaying the help for the jrecreate command: 
    

$ cd $EJDK_HOME
$ bin/jrecreate.sh -–help

Usage: jrecreate --help | --dest [options]
where options include:
...
  5. Use jrecreate to create a custom version of the JRE that will suit your device and applications, then copy the JRE to the embedded device. For more information, see Oracle Java SE Embedded Platform Developer’s Guide.

Compatibility

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.

Platform Support

This release of Oracle Java SE Embedded 8 was tested on Linux for ARM and x86 systems. The requirements of these systems are specified at Oracle Java SE Embedded System Requirements. For ARM, testing was done on the v5, v6 and v7 architectures. Headless mode was tested on all systems; headful mode was tested on ARMv6 and ARMv7 platforms.

Some of the information in this document describes support or issues concerning graphics, window managers, audio, and so forth, and therefore only applies to the headful release on ARMv6 and ARMv7.

Java support on ARM is specific to the GNOME Desktop Environment version 1:2.30+7.