Create /etc/systemd/system/jetty.service

[Unit]
Description=Jetty Web Application Server
After=syslog.target network.target

[Service]
Type=forking
ExecStart=/opt/jetty/bin/jetty.sh start
ExecStop=/opt/jetty/bin/jetty.sh stop

[Install]
WantedBy=multi-user.target
systemctl enable jetty
service jetty start