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milesd · Guest

Hello, I am rather new to Corba, and would like to know how to pass a
simple "Hello World" string "upstream" from one "Server" to another
"Server".

I have a corba RoomBooking Client and Server (which are below). I can
get client to call the server via a myRoom naming reference via
tnameserv - no worries.

WHAT I cannot figure out is how to get a number of room booking servers

to pass an object (could just be a "Hello World" string) from one
server to another server.

For example if I had started a client, and two server.

1. The client would call the first server, and pass a "Hello World
Message" to that server.
2. Server One accepts the "Hello World" message, and then Forks
(creates a thread), AND passes the message up-stream to server two (by
getting the Name context of Server Two).
3. Server Two receives the "Hello World" message, Forks and Passes it
back to the Client which called Server One with the initial message.

What I cannot figure out is how Servers One or Two fork (so they can
also accept connections) BUT also can pass a message upstream to
another Server.

Can someone please provide an easy to understand example, tutorial URL,

Chapter in a book. Source code would be very useful as a reference.

cheers

Miles.

----
// Client some code snipped

public HashMap getListofRooms() {

BindingListHolder blh = new BindingListHolder();
BindingIteratorHolder bih = new BindingIteratorHolder();
BindingHolder bh = new BindingHolder();

room_context.list(0, blh, bih);

Room myRoom;
HashMap myHash = new HashMap();

try {

if ( bih.value != null ) {
while ( bih.value.next_one( bh )) {
myRoom = RoomHelper.narrow( room_context.resolve(
bh.value.binding_name ));

if (myRoom != null) {
System.out.println( "FOUND ROOM: " +
myRoom.name() );
myHash.put( myRoom.name(), myRoom );
myRoom = null;
}
}
}
} catch (Exception e) {
System.out.println( e );
}

return ( myHash );
}

String hello = helloRef.sayHello();
----

AND a Corba Server which calls

public class RoomServer {
public static void main(String[] args) {
String context_name, str_name;

// You must specify your room name as a single argument

if ( args.length != 1 ) {
System.out.println("Usage: RoomServer roomName");
System.exit( 1 );
}

System.out.println("ROOM NAME: " + args[0]);

// context reference name

context_name = new String("BuildingApplications/Rooms");

try {
//init
ORB orb = ORB.init( args, null );
POA poa = POAHelper.narrow(
orb.resolve_initial_references(
"RootPOA"));
poa.the_POAManager().activate();

// create the Room object and export the object
reference
org.omg.CORBA.Object room_obj =
poa.servant_to_reference( new RoomImpl( args[0]
) );

// register with CORBA naming service
str_name = context_name + "/" + args[0];

NamingContextExt root = NamingContextExtHelper.narrow(
orb.resolve_initial_references("NameService")
);

try {
// make sure the "rooms" context is bound is
bound correctly
root.bind_new_context( root.to_name(
context_name ));
} catch( AlreadyBound ab ) {
// does not matter .
} catch( NotFound nf ) {
System.err.println("Context " + context_name +
" not found,
start MeetingFactoryServer first.");
System.err.println("exiting ...");
}

root.bind( root.to_name( str_name), room_obj );

// wait for incoming requests to be serviced
orb.run();
} catch( AlreadyBound already_bound ) {
System.err.println("Room " + context_name + args[0] +
" already bound.");
System.err.println("exiting ...");
} catch(UserException ue) {
ue.printStackTrace();
} catch(SystemException se) {
System.err.println(se);
}
}

}

//end

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