/usr/local/java/jdk1.8.0_66
sudo gedit /etc/profile
JAVA_HOME=/usr/local/java/jdk1.8.0_66 JRE_HOME=$JAVA_HOME/jre PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME export JRE_HOME export PATH
sudo update-alternatives --install "/usr/bin/java" "java" "/usr/local/java/jdk1.8.0_66/jre/bin/java" 1 sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/local/java/jdk1.8.0_66/bin/javac" 1 sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/local/java/jdk1.8.0_66/bin/javaws" 1
sudo update-alternatives --set java /usr/local/java/jdk1.8.0_66/jre/bin/java sudo update-alternatives --set javac /usr/local/java/jdk1.8.0_66/bin/javac sudo update-alternatives --set javaws /usr/local/java/jdk1.8.0_66/bin/javaws
. /etc/profile
References :