1) Add the Java repositories
apt-get install oracle-java8-installer mysql-server mysql-client mysql-common libmysql-java tomcat6 ant
2) Download the jetspeed installer
3) Remove tomcat6 package and then run the installer. The installer will install it’s own Tomcat6 but it helps if you have all the pre-req’s in place.
java -jar jetspeed-installer-2.2.2.jar
That’s really it. Give it the database info and it will build that for you too. Pretty simple. IMHO, it’s also butt ugly and not very intuitive.