topical media & game development
This chapter has given an overview of component technology.
It discussed standards for interoperability, including (D)COM,
CORBA and Java.
It gave an example application using both Java and CORBA,
and discussed the issues involved in extending an
existing library with CORBA.
- definitions -- components
- the technology matrix
- component myths -- (r)evolution
slide: Section 6.1: Objects versus components
In section 1,
we looked at some definitions of components
to clarify how component technology differs from
A brief overview of existing technology was given and
an attempt was made to demystify component-based development.
slide: Section 6.2: Standards for interoperability
In section 2 we looked in somewhat more
detail at component technologies that,
each in their own way, set a standard for interoperability.
slide: Section 6.3: The Java platform
In section 3,
we discussed the Java platform from a variety of perspectives,
as listed in slide
We weighted the pros and cons of Java
from each of these perspectives,
that Java is a promising platform.
- agent, workgroup, agenda, appointment
- CORBA server, Java applets
slide: Section 6.4: An Internet-based workgroup application
In section 4, we looked at the outline
of a simple workgroup application,
that allows for creating appointments mediated
by agents that act as a representative of a user.
The workgroup illustrates the use of Java applets
and CORBA servers.
- factories -- (distributed) object tables
- server wrappers -- remote objects
- client-side adaptors -- transparent typing
slide: Section 6.5: Crush -- extending hush with CORBA
Finally, in section 5,
we discussed the issues involved in extending a framework
such as hush with CORBA.
Apart from the definition of interfaces and server wrappers,
we defined client-side adaptors to attain a transparent
integration of CORBA object handles and the types
native to the framework.
- Give a definition of the notion of components.
How is this related to a definition of objects?
Explain the difference between these definitions.
- What actual component technologies can you think of?
How would you compare them?
- Describe Microsoft (D)COM, OMG CORBA, ODMG Persistent Objects.
Is there any relation between these standards?
- Discuss the Java platform.
What perspectives can you think of?
Discuss pros and cons.
- Describe the architecture of an Internet-based
What technology would you use?
- What issues may arise in extending a given library
or framework with CORBA?
Can you think of any solutions?
I recommend [Szyperski97], both as an introduction to
as a reference for more advanced readers.
For an introduction to CORBA, you may
read [Siegel96]. A readable account of the
ODMG standard is given in [Cattell94].
For more information on Java, again, visit
For information on (D)COM, look at
Learning how to program CORBA applications is probably best
learned from the manuals that come with your CORBA
For an evaluation of object store management and naming schemes
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