I have built a JCo Java application that can invoke RFC functions on SAP R/3 to get information or set information. This Java applications runs in either a standalone Java console or part of a Java web server. I want to investigate how I would do this on Microsoft IIS. I had some experience with Visual J++ where I could create a Java activeX component that could be access via a ASP page. I forgot how to do that.
However, by doing that, I have created extra layers that seem inefficient. I sawed the DCOM SAP Connector that is based on the ISAPConnector. That seems to be on the right path, but a bit more heavy-weight than the JCO library. (For example the dest of ISAPConnector is stored on the Windows registry -- not too horrible, but tolerable.) Can you suggest anything easier?
a) I personally would not spend any time anymore on the pre-.NET MS technologies.
b) Avoid J++. It supports only an ancient version of Java.
c) If for whatever reason you need to do MS stuff now (and cannot wait for .NET) then the SAP DCOM Connector is your best choice, although I personally agree that JCo is nicer.