With this patch multiple values can be updated.
The syntax is as follows:
http://localhost:8080/remote/http/create?auth=$token&path=/instance/Test/Test-1&inputAttributes=multiple={v1,2,3}
To install the patch unzip the zip file under <installdir>/tmocat*/webapps/ROOT/WEB-INF/classes. Restart OneCMDB.
Works for me with attributes of simple types (integer, string etc), but not for attributes of complex type (referencing other instances using their alias).
I described this behaviour in the forum, too:
https://sourceforge.net/projects/onecmdb/forums/forum/916038/topic/3576302/index/page/1.
Thank you very much for your efforts and great work!