Develop a middleware component for retrieving Weather Forecast information using CORBA?

Answer 1

Develop a middleware component for retrieving Weather Forecast information using CORBA

Program Code:

IDL Class:-

module Hello1

{

interface Hello

{

string sayHello();

};

};

Client Class:-

import Hello1.*;

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");

NamingContext ncRef = NamingContextHelper.narrow(objRef);

// resolve the Object Reference in Naming

NameComponent nc=new NameComponent ("Hello","");

NameComponent path[] = {nc};

helloImpl = HelloHelper.narrow(ncRef.resolve(path));

System.out.println(helloImpl.sayHello());

}

catch (Exception e)

{

System.out.println("ERROR : " + e) ;

}

}

}

Implement Class:

import Hello1.*;

import org.omg.CosNaming.*;

import org.omg.CosNaming.NamingContextPackage.*;

import org.omg.CORBA.*;

import java.util.Properties;

class HelloImpl extends _HelloImplBase

{

// implement sayHello() method

public String sayHello()

{

return "\nHello world !!\n";

}

}

Server Class:-

import Hello1.*;

import org.omg.CosNaming.*;

import org.omg.CosNaming.NamingContextPackage.*;

import org.omg.CORBA.*;

public class HelloServer {

public static void main(String args[]) {

try

{

// create and initialize the ORB

ORB orb = ORB.init(args, null);

// create servant and register it with the ORB

HelloImpl helloImpl = new HelloImpl();

orb.connect(helloImpl);

// get object reference from the servant

org.omg.CORBA.Object objRef =orb.resolve_initial_references("NameService");

// Use NamingContext

NamingContext ncRef = NamingContextHelper.narrow(objRef);

// bind the Object Reference in Naming

NameComponent nc=new NameComponent ("Hello","");

NameComponent path[] = {nc};

ncRef.rebind(path, helloImpl);

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

// wait for invocations from clients

orb.run();

}

catch (Exception e)

{

System.err.println("ERROR: " + e);

}

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

}

}

Output:

Impl Side:

Z:\Middle ware\corba1>idlj -fclient -fserver -implBase hello.idl

Z:\Middle ware\corba1>cd hello1

Z:\Middle ware\corba1\Hello1>javac *.java

Z:\Middle ware\corba1>tnameserv

Initial Naming Context:

IOR:000000000000002849444c3a6f6d672e6f72672f436f734e616d696e672f4e616d696e

67436f6e746578743a312e3000000000010000000000000054000101000000000d313732

2e31362e312e3130380000041f00000018afabcafe00000002584b271b000000080000000

000000000000000010000000100000014000000000001002000000000000101000000000

TransientNameServer: setting port for initial object references to: 900

Ready.

Server Side:

Z:\Middle ware\corba1>javac *.java

Z:\Middle ware\corba1>java HelloServer

HelloServer ready and waiting...

Client Side:

Z:\Middle ware\corba1>java HelloClient

Hello world!!

Answer 2

To develop a middleware component for retrieving Weather Forecast information using CORBA, you can create an interface that defines methods for fetching weather data from a remote server. Implement this interface in a CORBA object that handles communication with the server. Use the CORBA IDL to define the interface and then generate language-specific stubs and skeletons for communication. Finally, deploy the component on the server and client machines to enable remote method invocations for retrieving weather forecast information.