COM and CORBA® Side by Side

	Build-Related Batch Files
	Environment Variable Settings
	DCOM Issues Configuring DCOM Using dcomcnfg.exe DCOM Server Issues DCOM Client Issues
	CORBA Issues Orbix Server Issues Java IDL Issues Java Plug-in Issues

	_clean.bat - This batch file is used to clean up all generated files related to a build.
	_make.bat - This batch file is used to build a sample application.
	_run.bat - This batch file is used to run a sample application.

C:\>set
COMPUTERNAME=SCARPIA
ComSpec=C:\WINNT4\system32\cmd.exe
HOMEDRIVE=C:
HOMEPATH=\
INCLUDE=c:\vstudio6\vc98\include;c:\vstudio6\vc98\atl\include;
        c:\vstudio6\vc98\mfc\include;C:\Mts\Include
IT_CONFIG_PATH=C:\IONA\Orbix\CFG
LIB=c:\vstudio6\vc98\lib;c:\vstudio6\vc98\mfc\lib;C:\Mts\Lib
LOGONSERVER=\\TOSCA
NUMBER_OF_PROCESSORS=1
OS=Windows_NT
Os2LibPath=C:\WINNT4\system32\os2\dll;
Path=C:\WINNT4\system32;C:\WINNT4;c:\bin;c:\vstudio6\Common\MSDev98\Bin;
     c:\vstudio6\vc98\bin;c:\vstudio6\vb98;C:\Mts;c:\jdk121\bin;
     c:\iona\orbix\bin
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.JS
PROCESSOR_ARCHITECTURE=x86
PROCESSOR_IDENTIFIER=x86 Family 6 Model 6 Stepping 0, GenuineIntel
PROCESSOR_LEVEL=6
PROCESSOR_REVISION=0600
PROMPT=$P$G
SystemDrive=C:
SystemRoot=C:\WINNT4
TEMP=C:\TEMP
TMP=C:\TEMP
USERDOMAIN=HOME
USERNAME=jason
USERPROFILE=C:\WINNT4\Profiles\jason
windir=C:\WINNT4

	The first step is to properly configure DCOM. Microsoft provides the dcomcnfg.exe utility to configure DCOM.
	To configure DCOM, run dcomcnfg.exe on both your client and server machines.
	On the "Default Properties" tab of dcomcnfg: Set "Enable Distributed COM on this computer" to checked Set "Default Authentication Level" to "Packet" Set "Default Impersonation Level"  to "Impersonate"
	On the  "Default Security" tab Default Access Permissions    Everyone       Allow Access Default Launch Permissions    Everyone       Allow Launch

Here is an excerpt of the main() function from one of the Orbix server implementations.

int main()
{
    // *********************************************************
    // Uncomment the following if we want to rely on
    // the Orbix daemon. Since we're relying on pure
    // IIOP and IOR strings, we don't need this.
    //
    // CORBA::Orbix.setServerName(SRV_NAME);
    // *********************************************************

    // Create the factory implementation object.
    Ch3::CheckingAccountFactory_var factory =
        new CheckingAccountFactoryImpl;

    // Get the IOR for the factory.
    char* factoryIOR;

    try
    {
        // This call is not CORBA compliant.
        factoryIOR = factory->_object_to_string
                              (CORBA::IT_INTEROPERABLE_OR_KIND);
    }
    catch(CORBA::SystemException& sysEx)
    {
        cerr <<"Unexpected system exception " << endl;
        cerr << &sysEx ;
    }

    // Write the IOR to a file.
    ofstream strm("ior.txt");

    if ( !strm )
    {
        cout << "server: Unable to create IOR file - " << endl;
        return 1;
    }

    cout << "Writing IOR ("
         << factoryIOR
         << ") to ior.txt ..."
         << endl << endl << flush;

    strm << factoryIOR;
    strm.flush();
    strm.close();

    CORBA::string_free(factoryIOR);

    try
    {
        // *****************************************************
        // Uncomment the following if we want to rely on
        // the Orbix daemon. Since we're relying on pure
        // IIOP and IOR strings, we don't need this.
        //
        // CORBA::Orbix.impl_is_ready
        //      ((char*)SRV_NAME, CORBA::Orbix.INFINITE_TIMEOUT);
        // *****************************************************

        // Comment out the following if using impl_is_ready().
        CORBA::Orbix.processEvents(CORBA::Orbix.INFINITE_TIMEOUT);
    }
    catch (CORBA::SystemException &sysEx )
    {
        cerr << "Unexpected system exception"
             << &sysEx
             << endl;
        return 1;
    }

    // impl_is_ready() returns only when Orbix times-out
    // an idle server (or an error occurs).
    cout << "server exiting" << endl;

    return 0;
}

For my development purposes, I have a version of Java IDL (javaidl.jar) that works with Microsoft's JVM. To be honest, I'm not sure where I got it and I'd probably be violating redistribution laws if I placed it on this site. If you have a JDK 1.1 version of the Java IDL classes, you can probably do the same thing (the JDK 1.2 classes won't work). For commercial purposes, you'll certainly want to go with a commercial ORB that works with both JDK 1.2 and Microsoft's JVM. Once you have a .jar file with the appropriate classes, you'll want to create a registry entry like this.

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Java VM]
"Classpath"="C:\\WINNT4\\java\\classes;.;c:\\WINNT4\\java\\javaidl.jar;
             c:\\jre12\\lib\\rt.jar"