How do I compile zabbix-java-gateway.deb with openjdk-8?

[cesarsj]

When running systemctl start zabbix-java-gateway on Ubuntu 20.04 LTS, the error appears:

JavaGateway has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizable class file versions up to 52.0

The zabbix-java-gateway.deb package says it depends on default-jre-headless, which says it depends on openjdk-11-jre-headless. I already tried, in /etc/environment, to put JAVA_HOME = "/usr/lib/jvm/open-8-jdk-amd64", and then recompile the deb package, but the error persists.

[cesarsj]

I managed to solve the problem. In fact it is the opposite, and this is obvious, I who had not noticed, but the jdk11 was corrupted, and the system was already choosing jdk8, so I had to reinstall jdk11 to run the "systemctl start zabbix-java-gateway" and work.