put it into /etc/init.d/tomcat

tomcat_auto_reboot.sh

#!/bin/bash

### BEGIN INIT INFO
# Provides:        tomcat
# Required-Start:  $network
# Required-Stop:   $network
# Default-Start:   2 3 4 5
# Default-Stop:    0 1 6
# Short-Description: Start/Stop Tomcat server
### END INIT INFO

# Command:
# sudo chmod 755 /etc/init.d/tomcat
# sudo update-rc.d tomcat defaults

# then you can start|stop|restart with the following commands:
# sudo service tomcat <stop|start|restart>

export PATH=/sbin:/bin:/usr/sbin:/usr/bin
export JAVA_HOME=/usr/lib/jvm/java-7-sun
export PATH=${JAVA_HOME}/bin:$PATH
export CATALINA_HOME=/usr/local/tomcat
export PATH=${CATALINA_HOME}/bin:$PATH
#export JAVA_OPTS="-Dfile.encoding=UTF-8 \
#  -Dcatalina.logbase=/var/log/tomcat7 \
#  -Dnet.sf.ehcache.skipUpdateCheck=true \
#  -XX:+DoEscapeAnalysis \
#  -XX:+UseConcMarkSweepGC \
#  -XX:+CMSClassUnloadingEnabled \
#  -XX:+UseParNewGC \
#  -XX:MaxPermSize=128m \
#  -Xms512m -Xmx512m"
SHUTDOWN_WAIT=20

tomcat_pid() {
  echo `ps aux | grep org.apache.catalina.startup.Bootstrap | grep -v grep | awk '{ print $2 }'`
}

start() {
  pid=$(tomcat_pid)
  if [ -n "$pid" ] 
  then
    echo "Tomcat is already running (pid: $pid)"
  else
    # Start tomcat
    echo "Starting tomcat"
    ulimit -n 100000
    umask 007
    #/bin/su -p -s /bin/sh tomcat $CATALINA_HOME/bin/startup.sh
    sh ${CATALINA_HOME}/bin/startup.sh
  fi
  return 0
}

stop() {
  pid=$(tomcat_pid)
  if [ -n "$pid" ]
  then
    echo "Stoping Tomcat"
    #/bin/su -p -s /bin/sh tomcat $CATALINA_HOME/bin/shutdown.sh
    sh ${CATALINA_HOME}/bin/shutdown.sh
 
    let kwait=$SHUTDOWN_WAIT
    count=0;
    until [ `ps -p $pid | grep -c $pid` = '0' ] || [ $count -gt $kwait ]
    do
      echo -n -e "\nwaiting for processes to exit";
      sleep 1
      let count=$count+1;
    done
 
    if [ $count -gt $kwait ]; then
      echo -n -e "\nkilling processes which didn't stop after $SHUTDOWN_WAIT seconds"
      kill -9 $pid
    fi
  else
    echo "Tomcat is not running"
  fi
  return 0
}

status() {
  pid=$(tomcat_pid)
  if [ -n "$pid" ]
  then
    echo "Tomcat is running with pid: $pid"
  else
    echo "Tomcat is not running"
  fi
}

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