B
Comparing the Oracle8i JServer and VisiBroker VBJ ORBs

This appendix, which is for developers who are familiar with the VisiBroker VBJ ORB, summarizes the main differences between that ORB and the current version of the Oracle8i JServer ORB. Each ORB supports multiple styles of usage, but this appendix compares only the most commonly used styles. In particular, it assumes that VBJ clients use the helper bind() method to find objects by name, whereas Oracle8 i clients use the JNDI lookup() method for the same purpose. It also assumes that Oracle8 i clients use Oracle's session IIOP to communicate with server objects, though the JServer ORB also supports the standard IIOP used by the VBJ ORB.

The differences in the ORBs are summarized in these sections:

• Object References Have Session Lifetimes

• The Database Server is the Implementation Mainline

• Server Object Implementations are Deployed by Loading and Publishing

• Implementation by Inheritance is Nearly Identical

• Implementation by Delegation is Different

• Clients Look Up Object Names with JNDI

• No Interface or Implementation Repository

At the end of the appendix, equivalent client and server implementations of the same IDL for the VBJ and Aurora ORBs are provided for comparison.

---