Add the Java repository and update the package list
add-apt-repository ppa:webupd8team/java apt-get update
Check the current running version of Java. Assuming you're runing OpenJDK, remove it.
java -version apt-get purge openjdk-\\*
Installt he Oracle version of Java.
apt-get install oracle-java8-installer oracle-java8-set-default
Verify it.
java -version
No questions yet.