1. A brief look at CORBA

2. What is CORBA Common Object Request Broker Architecture developed by OMG Combine benefits of OO and distributed computing Distributed computing – distribute the execution of the business logic to the nodes that are most appropriate to handle it. Enabled by ORB mechanism Goal -provide the infrastructure to hide the the details of distributed object communication from the class designer.

3. ORB – the goal Application Objects Common Services Spreadsheet CAD Email Browser Object Request Broker StorageTransaction Management QueriesVersioningSecurity Object Services Connect multiple heterogeneous object systems transparently

4. ORB Handles distribution of messages between application objects Acts as a software bus enabling objects to make and receive requests and responses. ORB translates the requests/responses into a form that the provider/original requestor can understand

5. CORBA Defines an architecture of ORB based environments Elements include: IDL – interface definition language for describing class interfaces independently of the native implementation language. Compiler exists for supported languages (Smalltalk, C++, Java) Interface Repository – stores IDL definitions. Can be queried by a client to obtain a description of all the registered object interfaces, the methods they support, their parameters and exceptions.

6. CORBA request mechanisms CORBA provides two mechanisms for clients to issue requests to objects Static invocation- requires the client to have the IDL stub for each interface it uses on the server. this interface must be known at compile time Dynamic invocation – allows the client to identify objects and their interfaces at run-time (based on Interface Repository), then request services from these objects.