Two things are wrong, neither of which, however, make daemonize appropriate. First, and trivially, there's a missing /bin/java (-: Second, that's a potential readiness protocol and a main PID mismatch. See http://unix.stackexchange.com/a/200365/5132 for details. And then http://askubuntu.com/a/624871/43344 . Remembering to exec is another lesson to bring along from the daemontools world.
...
[Service]
Type=forking
EnvironmentFile=-/usr/local/myJavaConfig
ExecStart=/bin/sh -c '${JAVA_HOME} ${JAVA_OPTS}'
Or if you're after passing things in, use the other technique that lets you use systemctl myservice@your_sub.service