This is applicable only in a very exceptional situation where you must use a legacy version of Java because of other legacy programs that depend on it, on your system. Use this only when you cannot change your system wide Java version.

Change the Java path in etc/application.conf.

The default in etc/application.conf reads:

elixir.jobengine.launcher.java-program="java"

Change that line to:

elixir.jobengine.launcher.java-program="/full_path_to_java_excutable".

For example:

elixir.jobengine.launcher.java-program="/usr/bin/jre-8/bin/java"

Alternately, you can pass the full path to the Java executable, using the -D flag when running the run-server script.

For example:

sh run.server.sh -D /usr/bin/jre-8/bin/java

or

run-server.bat -D /usr/bin/jre-8/bin/java

depending on your operating system.