Installation of Java Developer Kits


(Huguenin) #1

I try to install openHAB… but I received this message :
image
Unfortunately, the link shows none “Developer Kit”. Where can I find it ?

System : Win7 32bits

Thanks for your help !

Gerald


(Rich Koshak) #2

Google is pretty helpful for questions like these:

https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

@Benjy, does that message come from our launch scripts or from Karaf? If it’s ours we should update the URL. I suspect it comes from Karaf and it’s out of our hands.


(Ben Clark) #3

This one comes from Karaf, but we keep a copy of it in our distribution so can modify it and report the problem upstream for it to be fixed later.

The message is a bit strange in general, the Linux script has no such warning and I’m assuming openHAB doesn’t work at all on a Java Runtime anyway?


(Rich Koshak) #4

I think the warning is that the JRE doesn’t support server-mode which has a different strategy for JIT (I think it’s more aggressive). For some reason, it’s included in the JDK though, which has never made sense to me. I remember a LOOONG time ago having to deal with this sort of distinction with WebLogic (before they were acquired by Oracle) and experimenting with differences between then Sun’s JRE and IBM’s JRE.

Some googling shows this decent summary with links to the original docs. It indeed relates to the compiler and some differences in heap and such. Client mode prioritizes fast startup whereas server mode prioritizes long term efficiencies.

But the difference shouldn’t impact the overall ability of Karaf to run. It just won’t run as well in client mode as it does in server mode. @Gerald2, does OH actually run? Or does it crash with the JRE?


(Huguenin) #5

Yes, all works perfectly… only this strange message at the start. And because this… I dont try to go head. Now I ignored that and all is alright.
Thanks for yours answeres !