Steps to set java version in your Ubuntu machine

Following are the steps to switch the java version of your Ubuntu machine , which is really useful to switch the default java version of your machine :

# sudo update-alternatives --install /usr/bin/java java <jdk_or_jre_firectory_where_u_unzipped_jdk_or_jre>/bin/java -1

Then execute the following command to pick which version you want to set:
#sudo update-alternatives --config java