I have written a Java server application that runs on a standard virtual hosted Linux solution. The application runs all the time listening for socket connections and creating new handlers for them. It is a server side implementation to a client-server application.
The way I start it is by including it in the start up rc.local script of the server. However once started I do not know how to access it to stop it and if I want to install an update, so I have to restart the server in order to restart the application.
On a windows PC, for this type of application I might create a windows service and then I can stop and start it as I want. Is there anything like that on a Linux box so that if I start this application I can stop it and restart it without doing a complete restart of the server.
My application is called WebServer.exe. It is started on server startup by including it in my rc.local as such:
java -jar /var/www/vhosts/myweb.com/phpserv/WebServer.jar &
I am a bit of a noob at Linux so any example would be appreciated with any posts. However I do have SSH, and full FTP access to the box to install any updates as well as access to a Plesk panel.
I wrote another simple wrapper here:
#!/bin/sh
SERVICE_NAME=MyService
PATH_TO_JAR=/usr/local/MyProject/MyJar.jar
PID_PATH_NAME=/tmp/MyService-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
You can follow a full tutorial for init.d here and for systemd (ubuntu 16+) here
If you need the output log replace the 2
nohup java -jar $PATH_TO_JAR /tmp 2>> /dev/null >> /dev/null &
lines for
nohup java -jar $PATH_TO_JAR >> myService.out 2>&1&