Java: Difference between revisions

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Java can be obtained in one of two flavors: Java Runtime Environment (JRE) or Java Development Kit (JDK). Unless you do programming in Java, JRE is usually sufficient for running programs and applets written in Java. JRE is also included in JDK so there is no need to install both.  There are two main flavors of Java that we have support for [http://www.oracle.com/us/technologies/java/overview/index.html Oracle Java] and [http://openjdk.java.net/ OpenJDK].  For the Java6 spec OpenJDK was not the same codebase and had some issues with some code that would run in the normal Oracle Java6 JVM.  The Java7 versions of OpenJDK is much closer if not the same codebase for Oracle Java and OpenJDK.
Java can be obtained in one of two flavors: Java Runtime Environment (JRE) or Java Development Kit (JDK). Unless you do programming in Java, JRE is usually sufficient for running programs and applets written in Java. JRE is also included in JDK so there is no need to install both.  There are two main flavors of Java that we have support for [http://www.oracle.com/us/technologies/java/overview/index.html Oracle Java] and [http://openjdk.java.net/ OpenJDK].


'''Note''': Support for Sun JDK 1.6.0 has ended and we will be purged from UMIACS supported systems in March 2013 due to many security vulnerabilities.  This does not impact the OpenJDK 1.6.0 versions as they are still maintained at this point.
==RHEL/Ubuntu==
The version of Java running can be checked by running the following command on any RHEL/Ubuntu machine. Alternative JDK and JRE options can be found in <tt>/usr/lib/jvm</tt>. <pre>bash-4.2$ java -version</pre>


=RHEL=
==Windows==
The default Java on these systems currently is Oracle Java 1.7.0.  We additionally have support for OpenJDK 1.6.0.  The alternative JDK and JRE options can be found in <tt>/usr/lib/jvm</tt>.
JRE is installed on all supported workstations by default and auto-updated to the latest version periodically. If for some reason your machine does not have Java, you may send a request to [mailto:staff@umiacs.umd.edu staff] to have JRE or JDK installed on your machine.
 
=Ubuntu=
The default Java on Ubuntu systems is OpenJDK 1.6.0 and 1.7.0 is available in the default repositories.
 
=Windows=
For PCs, you may send a request to [mailto:staff@umiacs.umd.edu staff] to have JRE or JDK installed on your machine.

Revision as of 20:19, 8 September 2016

Java can be obtained in one of two flavors: Java Runtime Environment (JRE) or Java Development Kit (JDK). Unless you do programming in Java, JRE is usually sufficient for running programs and applets written in Java. JRE is also included in JDK so there is no need to install both. There are two main flavors of Java that we have support for Oracle Java and OpenJDK.

RHEL/Ubuntu

The version of Java running can be checked by running the following command on any RHEL/Ubuntu machine. Alternative JDK and JRE options can be found in /usr/lib/jvm.

bash-4.2$ java -version

Windows

JRE is installed on all supported workstations by default and auto-updated to the latest version periodically. If for some reason your machine does not have Java, you may send a request to staff to have JRE or JDK installed on your machine.