Completely Un-Install Java from Ubuntu

I know, most of times (or should I say always ?) you feel need of installing JAVA from your Ubuntu Machine.  But how about, I installed Java and for some reasons, I don't want it on my machine anymore ?  
Well, here are few direct steps to achieve so.

• Remove all the Java related packages (Sun, Oracle, OpenJDK, IcedTea plugins, GIJ):

dpkg-query -W -f='${binary:Package}\n' | grep -E -e '^(ia32-)?(sun|oracle)-java' -e '^openjdk-' -e '^icedtea' -e '^(default|gcj)-j(re|dk)' -e '^gcj-(.*)-j(re|dk)' -e '^java-common' | xargs sudo apt-get -y remove

 

dpkg-query -W -f='${binary:Package}\n' | grep -E -e '^(ia32-)?(sun|oracle)-java' -e '^openjdk-' -e '^icedtea' -e '^(default|gcj)-j(re|dk)' -e '^gcj-(.*)-j(re|dk)' -e '^java-common' | xargs sudo apt-get -y remove

• Purge config files:

dpkg -l | grep ^rc | awk '{print($2)}' | xargs sudo apt-get -y purge

• Remove Java config and cache directory:

sudo bash -c 'ls -d /home/*/.java' | xargs sudo rm -rf

• Remove manually installed JVMs:

sudo rm -rf /usr/lib/jvm/*

• Remove Java entries, if there is still any, from the alternatives:

for g in ControlPanel java java_vm javaws jcontrol jexec keytool mozilla-javaplugin.so orbd pack200 policytool rmid rmiregistry servertool tnameserv unpack200 appletviewer apt extcheck HtmlConverter idlj jar jarsigner javac javadoc javah javap jconsole jdb jhat jinfo jmap jps jrunscript jsadebugd jstack jstat jstatd native2ascii rmic schemagen serialver wsgen wsimport xjc xulrunner-1.9-javaplugin.so; do sudo update-alternatives --remove-all $g; done

• Search for possible remaining Java directories:

sudo updatedb

sudo locate -b '\pack200' 

• If the command above produces any output like /path/to/jre1.6.0_34/bin/pack200 remove the directory that is parent of bin :

sudo rm -rf /path/to/jre1.6.0_34.