2.1.3 Defining utilities for sharing an object reference

Now we will define some utilities for communicating an object reference from the server to the client by converting the object reference into a string using ORB-supplied functions and writing it to a shared file. The client can then read the string from the shared file and convert it back into an object reference. Note that a real application would probably use a higher level service such as a Name Service for passing object references between applications.

  1. Create a file called shared.lisp .
  2. Enter the following Common Lisp code into the shared.lisp file:
(in-package "CL-USER")
(defparameter *hello-world-ior-file* 
  #+Win32 "c:/temp/hello.ior"
  #-Win32 "/tmp/hello.ior")
(defun object-to-file (orb object)
  (with-open-file (st *hello-world-ior-file* :direction :output
                                          :if-exists :supersede)
    (prin1 (op:object_to_string orb object) st)))
(defun file-to-object (orb)
  (with-open-file (st *hello-world-ior-file*)
    (op:string_to_object orb (read st))))

This code does the following:

(in-package "CL-USER") (require "corba-orb")
(defsystem hello-world-corba-object ()
  :members (
            ("hello-world" :type :idl-file)
:rules ((:in-order-to :compile "all
         (:requires (:load :previous)))))

Developing Component Software with CORBA - 23 Mar 2005