Ubuntu How to set default Java version?

sudo update-alternatives --config java 

matteo@matteo-ThinkPad-SL:~$ sudo update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).SelectionPathPriorityStatus------------------------------------------------------------*0/usr/lib/jvm/java-6.31-oracle/bin/java     1062auto mode
  1/usr/lib/jvm/java-6-openjdk/jre/bin/java   1061      manual mode
  2/usr/lib/jvm/java-6.31-oracle/bin/java     1062      manual mode

Press enter to keep the current choice[*], or type selection number: