First create a file in /etc/init.d/tomcat

sudo nano  /etc/init.d/tomcat

Then add the contents below

#!/bin/bash

PATH=/sbin:/bin:/usr/sbin:/usr/bin

start() {
 sh /home/server/tomcat/bin/startup.sh # Change this location to your tomcat directory
}

stop() {
 sh /home/server/tomcat/bin/shutdown.sh # Change this location to your tomcat directory
}

case $1 in
  start|stop) $1;;
  restart) stop; start;;
  *) echo "Run as $0 <start|stop|restart>"; exit 1;;
esac

Change permissions

chmod 755 /etc/init.d/tomcat

Update symlinks

update-rc.d tomcat defaults

Test, if you did everything correctly by

sudo service tomcat <stop|start|restart>