Developing Java Joint Client/Server Applications

#pragma prefix "beasys.com"

interface Callback

//This method prints the passed data in uppercase and lowercase
//letters.

{
	void print_converted(in string message);
};

interface Simple

//Call the callback object in the joint client/server application

{
		void call_callback(in string val, in Callback 		
				     callback_ref);
};

interface SimpleFactory
{
     Simple find_simple();
};

Step 2: Generating Skeletons and Client Stubs

//The implementation file for the Callback object. The Callback
//object implements the print_converted method.

class CallbackImpl extends _CallbackImplBase {

//Prints a string in upper and lower case

	public void print_converted(String data) {
	  if (data == null)
	       System.out.println("Null String");
	else
       {
		//Print input data in uppercase 
		System.out.println(data.toUpperCase());

		//Print input data in lowercase
		System.out.println(data.toLowerCase());
	}
   }
}

import com.beasys.Tobj.TP;

//The implementation file for the Simple interface. The Simple 
//interface implements the call_callback method of the Callback //object.

public class SimpleImpl extends _SimpleImplBase
{
	public void call_callback(String data, Callback 
                                 callback_ref)

//Call the print_converted method on the reference to the Callback
//object 
	{
	  callback_ref.print_converted(data);
	  return;
	}
}

import com.beasys.Tobj.TP;

//The implementation file for the SimpleFactory object. The
//SimpleFactory object provides methods to create a Simple object.


public class SimpleFactoryImpl extends _SimpleFactoryImplBase
{

//Create an object reference to a Simple object.

	public Simple find_simple()
	  {
		try {
			org.omg.CORBA.Object simple_oref =
			    TP.create_object_reference(
				SimpleHelper.id(),  // Repository id
				"simple_callback",  // object id
				null                // routing criteria
			       );

	// Send back the narrowed reference.

	              return SimpleHelper.narrow(simple_oref);

	    } catch (Exception e){
	         TP.userlog("Cannot create Simple: " +e.getMessage());
		e.printStackTrace();
		return null;
	    }
    }
}

Step 4: Initializing the ORB

properties prop = new Properties(System.getProperties());
prop.put("org.omg.CORBA.ORBclass", 
    "com.beasys.CORBA.iiop.ORB");
prop.put("org.omg.CORBA.ORBSingletonclass", 
    "com.beasys.CORBA.idl.ORBSingleton");
System.setProperties(prop);

//Initialize the ORB

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

Step 5: Writing the Client Portion of the Joint Client/Server Application

//Create a Bootstrap object
	Tobj_Bootstrap bootstrap = new Tobj_Bootstrap(orb,"");

//Create the Bootstrap object. The TOBJADDR system property 
//defines the host and port.

Tobj_Bootstrap bootstrap = new Tobj_Bootstrap(orb, "");

//Use the Bootstrap object to find the FactoryFinder object.

org.omg.CORBA.Object fact_finder_oref =
	bootstrap.resolve_initial_references("FactoryFinder");

//Narrow the FactoryFinder object.

FactoryFinder fact_finder_oref =
	FactoryFinderHelper.narrow(fact_finder_oref);

//Use the FactoryFinder object to locate a factory for the
//Simple object.

org.omg.CORBA.Object simple_fact_oref =
     fact_finder_oref.find_one_factory_by_id
     (SimpleFactoryHelper.id());

//Narrow the factory.

SimpleFactory simple_factory_oref =
     SimpleFactoryHelper.narrow(simple_fact_oref);

//Find the Simple object.

Simple simple = simple_factory_oref.find_simple();

Step 6: Creating a Callback Object Using the Callbacks Wrapper Object

import java.io.*;
import java.util.Properties;
import org.omg.CORBA.*;
import org.omg.CORBA.portable.ObjectImpl;
import com.beasys.*;
import com.beasys.Tobj.*;
import com.beasys.BEAWrapper.Callbacks;
...
//Create the servant for the Callback object

CallbackImpl callback_ref = new CallbackImpl();

//Use the Callbacks Wrapper object to create the callback object

Callbacks callbacks = new Callbacks(orb);

//Activate the servant and allow the ORB to accept
//callback requests.

callbacks.start_persistent_userid(callback_ref,
	((ObjectImpl)callback_ref)._ids() [0],
	"myID");
...

Step 7: Establishing a Connection to an ISH

...
//Register the callback port are specified in org.omg.CORBA.ORBport

bootstrap.register_callback_port(callback_ref);
...

Step 8: Invoking Operations on the Callback Object

...
//Call the call_callback method which invokes the Callback object

simple.call_callback(mixed, callback_ref);
...

Step 9: Specifying Configuration Information