tar -zxvf jdk-8u181-linux-x64.tar.gz

sudo mkdir /usr/java

sudo mv ./jdk1.8.0_181 /usr/java

sudo gedit /etc/profile

export JAVA_HOME=/usr/java/jdk1.8.0_181
export JRE_HOME=/usr/java/jdk1.8.0_181/jre
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

source /etc/profile