Running Java application as Linux service with systemd

While searching for this online I got about 2–3 different ways on how to configure systemctl commands to run my Jar Files.I am writing the best way which worked for me and should work for you guys too.Also, none of them explained it from a java developer’s perspective. My goal in this blog is to document my findings, the information that would save everyone the efforts of finding alternatives.

I assume you have your java code with all its dependencies in a jar file.This means you should right now be able to run your code using:
(sudo) java -jar Name_Of_File.jar

Ubuntu has a built-in mechanism to create custom services, enabling them to get started at system boot time and start/stop them as a service.

Create bash script to run your jar :

1. Create a vi /nano file under /usr/local/bin/ by running the following command
   eg. sudo vi /usr/local/bin/Service_Name.sh
   This will open a file Service_Name.sh.
2. Paste the following Code in your Service_Name.sh.
   Modify the SERVICE_NAME(Name of your Service), PATH_TO_JAR(Absolute Path to you jar File), and choose a PID_PATH_NAME(just replace Service_Name to your Service_Name keeping -pid at end ) for the file you are going to use to store your service ID.Only Changes needed are to the first 3 variables.

#!/bin/sh 
SERVICE_NAME=Your_Service_Name 
PATH_TO_JAR=/usr/Name_of_User/MyJavaApplication.jar 
PID_PATH_NAME=/tmp/Service_Name-pid 
case $1 in 
start)
       echo "Starting $SERVICE_NAME ..."
  if [ ! -f $PID_PATH_NAME ]; then 
       nohup java -jar $PATH_TO_JAR /tmp 2>> /dev/null >>/dev/null &      
                   echo $! > $PID_PATH_NAME  
       echo "$SERVICE_NAME started ..."         
  else 
       echo "$SERVICE_NAME is already running ..."
  fi
;;
stop)
  if [ -f $PID_PATH_NAME ]; then
         PID=$(cat $PID_PATH_NAME);
         echo "$SERVICE_NAME stoping ..." 
         kill $PID;         
         echo "$SERVICE_NAME stopped ..." 
         rm $PID_PATH_NAME       
  else          
         echo "$SERVICE_NAME is not running ..."   
  fi    
;;    
restart)  
  if [ -f $PID_PATH_NAME ]; then 
      PID=$(cat $PID_PATH_NAME);    
      echo "$SERVICE_NAME stopping ..."; 
      kill $PID;           
      echo "$SERVICE_NAME stopped ...";  
      rm $PID_PATH_NAME     
      echo "$SERVICE_NAME starting ..."  
      nohup java -jar $PATH_TO_JAR /tmp 2>> /dev/null >> /dev/null &            
      echo $! > $PID_PATH_NAME  
      echo "$SERVICE_NAME started ..."    
  else           
      echo "$SERVICE_NAME is not running ..."    
     fi     ;;
 esac

3. Write and quit the above file and give execution permisions :
ex. sudo chmod +x /usr/local/bin/Service_Name.sh

Test if Java Application is working with the following commands:

/usr/local/bin/./Service_Name.sh start
/usr/local/bin/./Service_Name.sh stop
/usr/local/bin/./Service_Name.sh restart

Creating a Service:

1. Create a file under /etc/systemd/system/ with nano or vi and paste the example script below.
   eg. sudo vi /etc/systemd/system/Service_Name.service

2.Insert the following code in Service_Name:

[Unit]
 Description = Java Service
 After network.target = Service_Name.service
[Service]
 Type = forking
 Restart=always
 RestartSec=1
 SuccessExitStatus=143 
 ExecStart = /usr/local/bin/Service_Name.sh start
 ExecStop = /usr/local/bin/Service_Name.sh stop
 ExecReload = /usr/local/bin/Service_Name.sh reload
[Install]
 WantedBy=multi-user.target

3.Write and quit this file.

Your Service is all set up.To Test your Java Application as a Service use the following commands to enable/start/stop/:

sudo systemctl daemon-reload
sudo systemctl enable Service_Name
sudo systemctl start  Service_Name
sudo systemctl stop   Service_Name

This should get your Java Application up and running as a System Service.

Enjoy and Feel free to reach out to me in case of any doubts/discrepancies.