I am new in the area of connectivity and integration and I have a question regarding supporting XA transactions. I have a EIS that supports XA transactions. Now, I want to integrate this EIS into a J2EE Application Server. Currently, there is no Resource Adapter (RA) implemented for this EIS. Is it mandatory to supply a RA for this EIS in order to enable this system to participate in XA transactions? Can a EIS be connected to an Application Server without using JCA, and make XA transactions work?