To change the version of “Java to use” for only the current profile, following commands have to be used in QSH (adapt JAVA_HOME path to match your system):
test -e /home/$(logname)/.profile || touch -C 1200 /home/$(logname)/.profile
echo "export JAVA_HOME=/QOpenSys/QIBM/ProdData/JavaVM/jdk70/64bit" >> /home/$(logname)/.profile
Previous commands check if "./profile" file for current user exists and if not creates this one and add the "JAVA_HOME" path into it.