Basic HTML version of Foils prepared May 19 1999

Foil 62 Narrowing

From CORBA Common Object Request Broker Architecture Basic Information Track Computational Science Course CPS616 -- Spring Semester 1999. by Geoffrey Fox, Wojtek Furmanski, Nancy McCracken, Chao-Wei Ou, Shrideep Pallickara
OMG IDL supports inheritance; the top of the hierarchy is Object in OMG IDL, org.omg.CORBA.Object in Java. (Note that both CORBA and Java define Object, but they are the tops of different type hierarchies.)
Some operations, notably name lookup and unstringifying, return org.omg.CORBA.Objects, which you narrow (using a helper class generated by idltojava) to the derived type you want the object to be. CORBA objects must be explicitly narrowed because the Java runtime cannot always know the exact type of a CORBA object.

© Northeast Parallel Architectures Center, Syracuse University, npac@npac.syr.edu

If you have any comments about this server, send e-mail to webmaster@npac.syr.edu.

Page produced by wwwfoil on Mon Jul 5 1999