Write the client-side code

Create the source file for the sample C++ client, arith.cpp. You can find a copy of arith.cpp in the samples/tutorial/cpp-corba/client subdirectory of your EAServer installation. Here is the source for arith.cpp:

/*
** arith.cpp -- Example C++ client for the EAServer C++
**   tutorial.
**
**   This program connects to EAServer,
**   creates an instance of the Tutorial/CPPArithmetic 
**   component, and invokes the multiply method.
**
** Usage:
**    arith iiop://<host>:<port>
**
**    Where:
**
**       <host> is the host name or IP address of the server machine. 
**
**       <iiop-port> is the server's IIOP port (9000 in the
**         default configuration).
**
*/

#include <stdio.h>
#include <iostream.h>
#include <string.h>
#include <Jaguar.hpp>
#include <SessionManager.hpp>
#include <Tutorial.hpp>    // Stubs for interfaces in Tutorial IDL 
                           // module.

int main(int argc, char** argv)
{
    const char *usage = 
"Usage:\n\tarith iiop://<host>:<iiop-port>\n";
    const char *tutorial_help =
"Verify that the"
"cpptut/CPPArithmetic component exists "
"and that it implements the "
"Tutorial::CPPArithmetic IDL interface.";

    const char *component_name = "cpptut/CPPArithmetic";

    try {

        if (argc < 2) 
	{
	  cout << usage;
          return -1;
        }

        char* manager_url = argv[1];

        cout << "**** Creating session\n";

        // Initialize the ORB
        CORBA::ORB_var orb = CORBA::ORB_init(argc, argv, 0);

	// Create a SessionManager::Manager instance
	
	CORBA::Object_var obj = 
 	   orb->string_to_object(manager_url);
	SessionManager::Manager_var manager = 
	  SessionManager::Manager::_narrow(obj);
        if (CORBA::is_nil(manager)) 
        {
	    cout << "Error: Null SessionManager::Manager instance. Exiting. "
	         << usage ;
            return -1;
        }

        // Create an authenticated session for user Guest
        // using password GuestPassword2

        SessionManager::Session_var session = 
	   manager->createSession("Guest", "GuestPassword2");
        if (CORBA::is_nil(session)) 
        {
	  cout << "Error: Null session. Exiting. " << usage;
          return -1;
        }

        // Obtain a factory for component instances by 
        // resolving the component name

        cout << "**** Creating component instance for " 
             << component_name << "\n" ;

        obj = session->lookup(component_name);
        SessionManager::Factory_var arithFactory = 
        SessionManager::Factory::_narrow(obj);

        if (CORBA::is_nil(arithFactory)) 
        {
	    cout << "ERROR: Null component factory for component " 
                 << component_name 
                 << tutorial_help ;
            return -1;
        }

	// Use the factory to create an instance.

        Tutorial::CPPArithmetic_var arith = 
           Tutorial::CPPArithmetic::_narrow(arithFactory->create());

        // Verify that we really have an instance.
        if (CORBA::is_nil(arith)) {
            cout << "ERROR: Null component instance. "
                 << tutorial_help ;
            return -1;
        }


        // Call the multiply method.

        cout << "**** Multiplying ...\n\n";
        CORBA::Double m1 = (CORBA::Double)3.1;
        CORBA::Double m2 = (CORBA::Double)2.5;
        CORBA::Double result = arith->multiply(m1, m2);

        cout << (double)m1 << " * " << (double)m2 
             << " = " << (double)result
             << "\n\n";

    }
    
    // Explicitly catch exceptions that can occur due to user error,
    // and print a generic error message for any other CORBA system 
    // exception.

    // Requested object (component) does not exist.
    catch ( CORBA::OBJECT_NOT_EXIST cone )
    {
        cout << "Error: CORBA OBJECT_NOT_EXIST exception. Check the "
             << "server log file for more information. Also verify "
             << "that the " << component_name 
             << " component has been created properly." << tutorial_help ;
    }

    // Authentication or authorization failure.
    catch ( CORBA::NO_PERMISSION npe )
    {
        cout << "Error: CORBA:: NO_PERMISSION exception. Check whether "
             << "login authentication is enabled for your server and "
             << "whether the component has restricted access. If so "
             << "edit the source file to use a valid user name and "
             << "password.\n";
    }

    // Invalid object reference.
    catch ( CORBA::INV_OBJREF cio ) 
    {
        cout << "Error: CORBA INV_OBJREF exception.";
    }

    // Communication failure. Server could be down or URL's port value
    // could be wrong.
    catch ( CORBA::COMM_FAILURE ccf ) 
    {
        cout << "Error: CORBA COMM_FAILURE exception. Check that the "
             << "specified host and IIOP port number are "
             << "correct and that the server is running. "
             << usage;
    }

    // Anything else.
    catch ( CORBA::OBJ_ADAPTER ) 
    {
        cout << "Error: CORBA::OBJ_ADAPTER \n";
    }
    catch ( CORBA::SystemException cse ) 
    {
        cout << "Error: CORBA System Exception. Check that the server "
             << "hostname and IIOP port are specified correctly, and "
             << "check the server's error log for more information.\n"
             << usage; 
    }

    return 0;
}