Outline

1
Outline

• CORBA Programming Elements
• Server Client Basics
• IDL Compiler
• CORBA Naming Service
• Utilities
• Demo

2
CORBA Programming Elements

• Object Request Broker (ORB)
• Interoperable Object Reference (IOR)
• Object Adapters
• Client
• Servant (Implementation)

3
Conceptual view of ORB
4
Object Request Broker

• provides all the communication infrastructure
  needed to identify and locate objects
• lookup and instantiate objects on remote machines
  
• handle connection management
• deliver data and request communication
• invoke methods on a remote object

5
Interoperable Object Reference

• Global identifier string
• identifies the machine on which its associated
  object is located
• the interface that the object supports
• Examples
• IOR000000000000001c49444c3a42616e6b2f4163636f756e
  744d616e616765723a312e3000000000010000000000000050
  000102000000000f3133372e3138392e38382e313733000080
  9b00000000002b00504d43000000040000000f2f62616e6b5f
  706f727461626c6500200000000b42616e6b4d616e61676572
  0000000000

6
Object Adapters

• provides an interface between the ORB and the
  object implementation
• Registration of server object implementations
  with the Implementation Repository
• Mapping of object references to their
  implementations

7
Server Basics

• Steps for setting up server
• Initialize the ORB
• Create and Setup the POA
• Activate the POA Manager
• Creating and activating the objects
• Wait for client requests

8
Client Basics

• Steps for setting up client
• Initializing the ORB
• Binding to objects
• Invoking operations on an object

9
IDL compiler

• Examples IDL (Bank.idl)
• module Bank
• interface Account
• float balance()
• interface AccountManager
• Account open(in string name)
• Usage
• idl2java Bank.idl

10
Implementation

• AccountImpl.java
• public class AccountImpl extends Bank.AccountPOA
  
• public AccountImpl(float balance)
• _balance balance
• public float balance()
• return _balance
• private float _balance

11
Naming Service

• bind a name to one of its objects
• associate one or more logical names with an
  object reference
• store logical names in a namespace
• obtain an object reference by using the logical
  name assigned to that object

12
Utilities

• idl2java
• osagent
• nameserv
• vbj
• vbjc

13
Run Sample

• Starting Smart Agent if no osagent
• osagent
• Starting Naming Service
• nameserv DEMO
• Running Server
• vbj -DSVCnamerootDEMO Server
• Running Client
• vbj -DSVCnamerootDEMO Client

14
Demo