How to start a Java program as a Linux daemon with an /etc/init.d script.

See also:

• http://www.source-code.biz/snippets/java/7.htm
• JBoss Daemon Startup Script
• Waiting for a process to stop

Here is the CentOS/RedHat/Ubuntu version of the SUSE script:

#!/bin/bash

#

# chkconfig: 345 99 05

# description: Java deamon script

#

# A non-SUSE Linux start/stop script for Java daemons.

#

# Derived from -

# Home page: http://www.source-code.biz

# License:   GNU/LGPL (http://www.gnu.org/licenses/lgpl.html)

# Copyright 2006 Christian d'Heureuse, Inventec Informatik AG, Switzerland.

#

# History:

# 2010-09-21 Josh Davis: Changed 'sudo' to 'su', fix some typos, removed unused variables

# 2009-03-04 Josh Davis: Ubuntu/Redhat version.

# 2006-06-27 Christian d'Heureuse: Script created.

# 2006-07-02 chdh: Minor improvements.

# 2006-07-10 chdh: Changes for SUSE 10.0.

# Set this to your Java installation

JAVA_HOME=/usr/java/latest

serviceNameLo="myservice"                                  # service name with the first letter in lowercase

serviceName="MyService"                                    # service name

serviceUser="appuser"                                      # OS user name for the service

serviceGroup="appgroup"                                    # OS group name for the service

applDir="/var/lib/$serviceNameLo"                          # home directory of the service application

serviceUserHome="/home/$serviceUser"                       # home directory of the service user

serviceLogFile="/var/log/$serviceNameLo.log"               # log file for StdOut/StdErr

maxShutdownTime=15                                         # maximum number of seconds to wait for the daemon to terminate normally

pidFile="/var/run/$serviceNameLo.pid"                      # name of PID file (PID = process ID number)

javaCommand="java"                                         # name of the Java launcher without the path

javaExe="$JAVA_HOME/bin/$javaCommand"                      # file name of the Java application launcher executable

javaArgs="-jar $applDir/myservice.jar"                     # arguments for Java launcher

javaCommandLine="$javaExe $javaArgs"                       # command line to start the Java service application

javaCommandLineKeyword="myservice.jar"                     # a keyword that occurs on the commandline, used to detect an already running service process and to distinguish it from others

# Makes the file $1 writable by the group $serviceGroup.

function makeFileWritable {

   local filename="$1"

   touch $filename || return 1

   chgrp $serviceGroup $filename || return 1

   chmod g+w $filename || return 1

   return 0; }

# Returns 0 if the process with PID $1 is running.

function checkProcessIsRunning {

   local pid="$1"

   if [ -z "$pid" -o "$pid" == " " ]; then return 1; fi

   if [ ! -e /proc/$pid ]; then return 1; fi

   return 0; }

# Returns 0 if the process with PID $1 is our Java service process.

function checkProcessIsOurService {

   local pid="$1"

   if [ "$(ps -p $pid --no-headers -o comm)" != "$javaCommand" ]; then return 1; fi

   grep -q --binary -F "$javaCommandLineKeyword" /proc/$pid/cmdline

   if [ $? -ne 0 ]; then return 1; fi

   return 0; }

# Returns 0 when the service is running and sets the variable $pid to the PID.

function getServicePID {

   if [ ! -f $pidFile ]; then return 1; fi

   pid="$(<$pidFile)"

   checkProcessIsRunning $pid || return 1

   checkProcessIsOurService $pid || return 1

   return 0; }

function startServiceProcess {

   cd $applDir || return 1

   rm -f $pidFile

   makeFileWritable $pidFile || return 1

   makeFileWritable $serviceLogFile || return 1

   cmd="nohup $javaCommandLine >>$serviceLogFile 2>&1 & echo $! >$pidFile"

   su -m $serviceUser -s $SHELL -c "$cmd" || return 1

   sleep 0.1

   pid="$(<$pidFile)"

   if checkProcessIsRunning $pid; then :; else

      echo -ne "n$serviceName start failed, see logfile."

      return 1

   fi

   return 0; }

function stopServiceProcess {

   kill $pid || return 1

   for ((i=0; i<maxShutdownTime*10; i++)); do

      checkProcessIsRunning $pid

      if [ $? -ne 0 ]; then

         rm -f $pidFile

         return 0

         fi

      sleep 0.1

      done

   echo -e "n$serviceName did not terminate within $maxShutdownTime seconds, sending SIGKILL..."

   kill -s KILL $pid || return 1

   local killWaitTime=15

   for ((i=0; i<killWaitTime*10; i++)); do

      checkProcessIsRunning $pid

      if [ $? -ne 0 ]; then

         rm -f $pidFile

         return 0

         fi

      sleep 0.1

      done

   echo "Error: $serviceName could not be stopped within $maxShutdownTime+$killWaitTime seconds!"

   return 1; }

function startService {

   getServicePID

   if [ $? -eq 0 ]; then echo -n "$serviceName is already running"; RETVAL=0; return 0; fi

   echo -n "Starting $serviceName   "

   startServiceProcess

   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi

   echo "started PID=$pid"

   RETVAL=0

   return 0; }

function stopService {

   getServicePID

   if [ $? -ne 0 ]; then echo -n "$serviceName is not running"; RETVAL=0; echo ""; return 0; fi

   echo -n "Stopping $serviceName   "

   stopServiceProcess

   if [ $? -ne 0 ]; then RETVAL=1; echo "failed"; return 1; fi

   echo "stopped PID=$pid"

   RETVAL=0

   return 0; }

function checkServiceStatus {

   echo -n "Checking for $serviceName:   "

   if getServicePID; then

    echo "running PID=$pid"

    RETVAL=0

   else

    echo "stopped"

    RETVAL=3

   fi

   return 0; }

function main {

   RETVAL=0

   case "$1" in

      start)                                               # starts the Java program as a Linux service

         startService

         ;;

      stop)                                                # stops the Java program service

         stopService

         ;;

      restart)                                             # stops and restarts the service

         stopService && startService

         ;;

      status)                                              # displays the service status

         checkServiceStatus

         ;;

      *)

         echo "Usage: $0 {start|stop|restart|status}"

         exit 1

         ;;

      esac

   exit $RETVAL

}

main $1