== Java under Scientific Linux ==
Sun's Java 6 will hit its end of life at the end of 02/2013, there will be no more security updates for this software after that date. It is the default Java runtime on our Scientific Linux machines and a replacement for SL5/SL6 is needed.

=== Update Plan ===
Java 1.7.0 from Oracle works with all tested applications. The Firefox plugin is not used by anything we know of and will be removed.

==== SL5 ====
 * JPackage Java 1.7.0 from Oracle, 64 Bit, no firefox plugin
 * removal of '''all''' Java packages from products, including Java 1.5
  * Intel Debugger 11.0 depends on Java 1.6 and will be removed
 * Openjdk on some systems (tomcat servers)
==== SL6 ====
 * JPackage Java 1.7.0 from Oracle, 64 Bit, no firefox plugin
  * users can install firefox plugin via GUI
==== User testing needed ====
Scientific Linux users can test Java 7 already on the machines lx64 (SL5, 64 bit) and sl6.

=== Technical Information for SL admins ===

==== Versions ====
The following versions of Java are currently available on Scientific Linux at DESY:
 * proprietary JDK (Sun/Oracle), version 6 or 7
  * full java, includes firefox plugin and javaws
 * Openjdk from Red Hat, included in SL5, SL6
  * version 6: optional firefox plugin and javaws on SL6 only
  * version 7
 * GCJ native tools, used for build tools like ant only
==== Package Types ====
Java can be installed from the following package types:
 * official Oracle rpm
  * package name is always jdk or jre for Java 6/7
 * JPackage.org style system rpm
  * uses update-alternatives to switch between JDK installations, e.g. /usr/bin/java
  * Red Hat Openjdk packages shipped with SL
  * Oracle Java packages built by us
 * prpm for /opt/products installation, built by us

==== Current Status ====
===== SL5 =====
 * Products: 32 Bit and 64 Bit versions, even Java 5 still installed <!>
 * JPackage Java 1.6.0 from Sun 32 Bit
  * 32 bit Firefox works with 32 bit java plugin only
 * JPackage Java 1.6.0 from Sun 64 Bit on some systems
 * Red Hat Openjdk6 on some systems
===== SL6 =====
 * JPackage Java 1.6.0 from Sun 64 Bit
 * JPackage Java 1.7.0 from Sun 64 Bit on some systems
===== Important applications using Java =====
 * passwd: uses whatever /usr/bin/java points to
 * `SeeVogh`: needs javaws
 * Tomcat: works with openjdk
 * dcache: needs Sun/Oracle JRE

==== Conclusion ====
The official rpm packages from Oracle are not suited for installation of more than one version. JPackage compatible packages allow easy coexistence of Red Hat Openjdk and proprietary JREs. Oracle Java 1.7.0 works with the tested applications. Openjdk version of javaws is only available on SL6 and depends on Openjdk 6, so this would be needed in addition to the latest Java version 7. There is no important application known depending on the mozilla plugin.