Why Zabbix Java Gateway works, 4.0

The most precious settings is:

JAVA_OPTIONS="$JAVA_OPTIONS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=12345 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=127.0.0.1"

Java gateway config:

Proxy server must be configured to communicate with gateway. Most important part is having:

JavaGateway=127.0.0.1
StartJavaPollers=5

Template to discover some items:

Minimal template:

This file should not be touched out of defaults: