USING GOOGLE IABHELPER DIRECTLY

HI.

"Androidjavaobject" and "Androidjavaclass" is for making class form a ".jar" file directly,and now i want to add google IN APP BILLING in my unity project,the in app billing api v3 giving a group of classes for more easier to work with the api call "iabhelper.java" .i wonder can i just simply compile the iabhelper to a single jar,and use it directly by "Androidjavaobject" and "Androidjavaclass" ?