Amabri - with custom java - version

[Satyanarayana Jampa]

Hi,
                I am configuring java-1.8 to be used with Ambari during the 
"ambari-server setup" option. Also, I added the java-1.8 on all the nodes 
manually and have set the class path and JAVA_HOME.
                While installing Hadoop components, the Ambari is installing 
its default java-version, instead of using the existing java-1.8.
                How can we say Ambari not to install pre-packaged java and use 
the one which was manually setup on all the datanodes.

Thanks,
Satya.