root@jenkins:~# service jenkins restart
[ ok ] Restarting Jenkins Continuous Integration Server: jenkins.
apt-get update
apt-get install openjdk-6-jdk
wget -q -O - http://pkg.jenkins-ci.org/debian-stable/jenkins-ci.org.key | apt-key add -
echo "deb http://pkg.jenkins-ci.org/debian-stable binary/" >> /etc/apt/sources.list
apt-get update
apt-get install jenkins