To start a Jetty Server, you can type the following command.
java -jar start.jar
The only way to stop the Jetty Server is by pressing Ctrl + C in the shell prompt.
Actually, there is a way to issue a stop command to the Jetty Server on another shell prompt. But you have to specify the STOP.PORT and STOP.KEY in the start command as follow.
java -DSTOP.PORT=8080 -DSTOP.KEY=stop_jetty -jar start.jar
After the Jetty Server is started, you can open another shell prompt and stop the Jetty by
java -DSTOP.PORT=8080 -DSTOP.KEY=stop_jetty -jar start.jar --stop