An Object-Oriented Approach
A D V E R T I S E M E N T
CORBAservices provide the basic
functionality for the management of objects during their lifetimefor example,
this includes:
- Naming (uniquely specifying a particular object instance)
- Security (providing auditing, authentication, etc.)
- Persistence (allowing object instances to be flattened to or
created from a sequence of bytes)
- Trading (providing objects and ORBs a mechanism to advertise
particular functionality)
- Events (allows an object to dynamically register or unregister an
interest in a particular type of event, essentially decoupling the
communication from the object)
- Life-cycle (allows objects to be created, copied, moved, deleted)
Common Facilities provide the
frameworks necessary for application development using distributed objects.
These frameworks are classified into two distinct groups: horizontal facilities
(commonly used in all applications, such as user-interface management,
information management, task management and system management), and vertical
facilities (related more to a particular industry, for example
telecommunications or health care).
The CORBA standard specifies an entity called the Object Request Broker
(ORB), which is the glue that binds objects together to enable higher-level
distributed collaboration. It enables the exchange of CORBA requests between
local and remote objects. Figure 3 shows the architecture of CORBA. Figure 4
shows the invocation of methods on different remote objects via the ORB.
Figure 3. Common Object Request Broker Architecture
(CORBA)
Figure 4. Calling a method within a specific object
instance
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