Openhab2 in xpenology with dsm 5.2

Hello , I need help !
I wanto to install openhab 2 into dsm 5.2 . I know that OH2 wants JVM8 . Dsm 5.2 support up to jvm 7 i think .
I don’t want to install oh2 in a docker container . I don’t want to upgrade to dsm 6 for now.
There is a way to install oh2 pachage into dsm 5.2 ?
Someone have experience in this configuration ?