Need Simple Example of Java Access to SAP Customer/Order Record

I need to create a simple demonstration application that uses a Java class to read/update an SAP customer record and an SAP order record.

I just downloaded with SAP Netweaver 04 Web Application Server 6.40 Trial. Can I create my sample application with this? Does it include a base R/3 (or stripped down R/3) system from which I can read/update a customer record and/or an order record? From my preliminary look at it, it just seems like a J2EE server. Where is the core SAP stuff that I'm supposed to integrate with using the Netweaver J2EE??

I'm a Java developer, but am clueless about SAP, so any help would be appreciated greatly.

-- Mark