Change JDK version in Feisty part1:terminal

from http://weblogs.java.net/blog/kirillcool/

    The Problem is when I installed eclipse and sun-java6 but in eclipse's configuration and java command in terminal was version 1.4

This is how to change version in terminal and another note  is for eclipse

   1. list the JDKs by update-alternatives command:
          * update-alternatives --list java // now you can see the list of JDK
   2. change JDK :
          * update-alternatives --set java /some/path/to/JDK
          * examples : sudo update-alternatives --set java /usr/lib/jvm/java-6-sun/jre/bin/java          // for my laptop
   3. That's it!!!!