2.1.5 Implementing the server

Implementing the server is also easy. We create a file
hello-world-server.lisp .

In the server the main function is less interesting because it is concerned with the administrative details of writing out a stringified form of the object reference into the shared file and initializing the server. The actual core of the application implementation is:

(corba:define-method op:hello ((self world-implementation))

  (declare (ignore self))

  "Hello World!")

This subclasses a special generated class on the server side called a servant , and then implements a method on op:hello that actually returns the desired string.

1. Create a file called hello-world-server.lisp.
2. Enter the following code into hello-world-server.lisp :
(in-package "CL-USER") (defclass world-implementation (HelloWorld:world-servant) ())

(corba:define-method op:hello ((self world-implementation))

  (declare (ignore self))

  "Hello World!")

(defun server-startup ()

  (let* ((orb (op:orb_init nil "LispWorks ORB"))

         (poa (op:resolve_initial_references orb "RootPOA"))

         (impl (make-instance 'world-implementation))

         (world (op:narrow 'HelloWorld:world

                           (op:servant_to_reference poa impl))))

    (object-to-file orb world)

    (let ((manager (op:the_poamanager poa)))

      (op:activate manager))))

3. Add hello-world-server to the defsystem by adding one line of code to the defsys.lisp file, which should then look like this:

(defsystem hello-world-corba-object ()

  :members (

            ("hello-world" :type :idl-file)

            "shared"

            "hello-world-server"

            "hello-world-client"

            ))

:rules ((:in-order-to :compile :all

         (:requires (:load :previous)))))