NewCORBA

The New CORBA 10 Step Recipe
http://java.sun.com/j2se/1.4.2/docs/guide/idl/jidlExample.html

Following is a Hello Corba Example that can be found in the
JDK 1.4 distribution. This 'recipe' uses new CORBA features
including the POA Adapter extension and the ORB daemon
in place of tnameserv.

1. Write the IDL interface

module HelloApp
{
interface Hello
{
    string sayHello();        // This line is an operation statement.
    oneway void shutdown();   // This line is another
};
};

2. Translate using idlj

> idlj Hello.idl

// generates HelloApp directory with CORBA class suite

3. Compile the Generated Classes

> javac HelloApp/*.java

4. Create Implementation Class

// extends HelloPOA rather than the Implementation Base class

import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import org.omg.PortableServer.*;
import org.omg.PortableServer.POA;

class HelloImpl extends HelloPOA {
private ORB orb;

public void setORB(ORB orb_val) {
    orb = orb_val;
}

// implement sayHello() method
public String sayHello() {java
    return "\nHello world !!\n";
}

// implement shutdown() method
public void shutdown() {
    orb.shutdown(false);
}
}

5. Create Server

// HelloServer.java
// Copyright and License

import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import org.omg.PortableServer.*;
import org.omg.PortableServer.POA;

import java.util.Properties;

public class HelloServer {

public static void main(String args[]) {
    try{
      // create and initialize the ORB
      ORB orb = ORB.init(args, null);

      // get reference to rootpoa & activate the POAManager
      POA rootpoa = POAHelper.narrow(orb.resolve_initial_references("RootPOA"));
      rootpoa.the_POAManager().activate();

      // create servant and register it with the ORB
      HelloImpl helloImpl = new HelloImpl();
      helloImpl.setORB(orb);

      // get object reference from the servant
      org.omg.CORBA.Object ref = rootpoa.servant_to_reference(helloImpl);
      Hello href = HelloHelper.narrow(ref);

      // get the root naming context
      org.omg.CORBA.Object objRef =
          orb.resolve_initial_references("NameService");
      // Use NamingContextExt which is part of the Interoperable
      // Naming Service (INS) specification.
      NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);

      // bind the Object Reference in Naming
      String name = "Hello";
      NameComponent path[] = ncRef.to_name( name );
      ncRef.rebind(path, href);

      System.out.println("HelloServer ready and waiting ...");

      // wait for invocations from clients
      orb.run();
    }

      catch (Exception e) {
        System.err.println("ERROR: " + e);
        e.printStackTrace(System.out);
      }

      System.out.println("HelloServer Exiting ...");

}
}

6. Create Client

// Copyright and License

import HelloApp.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
public class HelloClient
{
static Hello helloImpl;

public static void main(String args[])
    {
      try{
        // create and initialize the ORB
    ORB orb = ORB.init(args, null);

        // get the root naming context
        org.omg.CORBA.Object objRef =
        orb.resolve_initial_references("NameService");
        // Use NamingContextExt instead of NamingContext. This is
        // part of the Interoperable naming Service.
        NamingContextExt ncRef = NamingContextExtHelper.narrow(objRef);

        // resolve the Object Reference in Naming
        String name = "Hello";
        helloImpl = HelloHelper.narrow(ncRef.resolve_str(name));

        System.out.println("Obtained a handle on server object: " + helloImpl);
        System.out.println(helloImpl.sayHello());
        helloImpl.shutdown();

    } catch (Exception e) {
          System.out.println("ERROR : " + e) ;
    e.printStackTrace(System.out);
    }
    }
}

7. Compile classes

> javac HelloImpl.java
> javac HelloServer.java
> javac HelloClient.java

8. Start orbd

Usage: orbd <options>

where <options> includes:
-port                  Activation Port where the ORBD should be started, default 1049 (optional)
-defaultdb             Directory for ORBD files, default "./orb.db" (optional)
-serverid              Server Id for ORBD, default 1 (optional)
-ORBInitialPort        Initial Port (required)
-ORBInitialHost        Initial HostName (required)

// To start orbd from a UNIX command shell, enter:

> orbd -ORBInitialPort 1050&

// From an MS-DOS system prompt (Windows), enter:

>  start orbd -ORBInitialPort 1050        // note 'start' 


Note that 1050 is the port on which you want the name server to run.
The -ORBInitialPort argument is a required command-line argument.

9. Start server

>  java HelloServer -ORBInitialPort 1050 -ORBInitialHost localhost&

// on Linux it worked with or without the ampersand

10. start client

>  java HelloClient -ORBInitialPort 1050 -ORBInitialHost localhost