[Unit] 
Description=start and stop the minecraft-server 

[Service]
WorkingDirectory=/srv/minecraft
User=minecraft
Group=minecraft
Type=forking
ExecStart=/usr/bin/screen -dmS MinecraftServer /usr/bin/java -Xms1536M -Xmx1536M -jar server.jar --nogui

[Install]
WantedBy=multi-user.target