Ok thats really good to know in general.
/usr/lib/jvm/java-8-openjdk-amd64/bin/java -server -Xms${MIN_RAM} -Xmx${MAX_RAM} ${JAVA_PARAMETERS} -jar ${FORGE_JAR} nogui
where "/usr/lib/jvm/java-8-openjdk-amd64/bin/java" is the direct path to java 8.
This works. ?
Now i just need to create some $java8 system variable and im satisfied ?