Is it possible to upgrade Java compiler used on Timus from jdk 1.5 to jdk 1.6?

Java 6 is standard for ACM ICPC World finals (http://icpc.baylor.edu/systems/finals/ words "Java (version 1.6)") and NEERC semifinals (http://neerc.ifmo.ru/information/contest-rules.html words "Java 2 SDK 6.0").

Java 6 has some features that absent in Java 5. Example is ability to jump to next/previous key in TreeSet/TreeMap.