26 Distributed Java Applications

Michael Stal, Siemens AG

Waterfront Centre Hotel
Waterfront Ballroom C

Building distributed systems using Java is a complex task. First of all, there is a whole bunch of different technologies that might be used. Which one are we going to choose for a specific application context? Second, architectural issues must also be considered when developing distributed systems. Some low-level mechanisms such as sockets lead to systems that are very complex to understand, extend and maintain. The solution to this problem is the combination of distribution technologies and object-oriented programming. In this context, objects represent the units of distribution. Due to encapsulation and polymorphism distributed object models are possible that can be easily integrated into the object models of programming languages. Thus, mastering the complexity of distributed systems becomes easier and architectural drifts between different paradigms can be avoided. Standards such as Java RMI, OMG CORBA and Microsoft DCOM provide distributed object models on a wide range of different platforms. This is a major reason why most developers will inevitably need to understand the underlying concepts of distributing objects. Using Java helps to build distributed objects that are not bound to a single native system, but can be migrated to all machines where a Java Virtual Machine is running. Here, the benefits of distributed object computing and Java platform neutrality can be combined in previously unforeseen ways.

The goal of the tutorial is to introduce, classify, and compare different communication mechanisms applicable for building distributed systems using Java. Attendees will gain knowledge in fundamental concepts of distributed object computing as well as essential architectural aspects. The tutorial tries to prepare attendees with the knowledge to classify and evaluate these technologies and to choose among them.

Attendee Background: Participants should have a general familiarity with programming in Java. It is assumed that the audience is familiar with object-oriented concepts. Knowledge in distribution technologies is useful, but not required

Michael Stal is responsible for the research project Distributed Object Computing at Siemens AG. His main research areas are object-orientation, distribution, design patterns, and Java. He is co-author of the book "Pattern-Oriented Software Architecture - A System of Patterns," Wiley & Sons, 1996. He is also editor of Java Spektrum, a german SIGS magazine on Java. Michael is member of the Object Management Group. He has many publications in object technology magazines, and has given talks and tutorials at many object technology conferences and forums.

26

Distributed Java Applications

Other tutorials in the Java thread are:

Other tutorials in the distributed object computing thread are:

for beginners (yellow):
Tutorial 25: From C++ to Advanced Java in 1/2 day Tutorial 40: Java from UML Tutorial 53: A Practical Guide to Java on the Server Tutorial 15T: Introduction to Concurrent Object-Oriented Programming in Java

for intermediates (option 1- green):
Tutorial 15, 15T: Introduction to Concurrent Object-Oriented Programming in Java Tutorial 39: Designing Concurrent Object-Oriented Programs in Java Tutorial 52, 52T: Java Beans: Specifications, Design and Test Tutorial 53: A Practical Guide to Java on the Server

for intermediates (option 2- grey):
Tutorial 16: An Introduction to the Java Foundation Classes (JFC) Tutorial 40: Java from UML Tutorial 52, 52T: Java Beans: Specifications, Design and Test Tutorial 53: A Practical Guide to Java on the Server

for beginners (yellow):
Tutorial 6, 6R: OMG's CORBA and Object Management Architecture Tutorial 17, 17T*: Introduction to Distributed Computing Using Objects

for intermediates (green):
Tutorial 6, 6R: OMG's CORBA and Object Management Architecture Tutorial 66T: Testing Distributed Object Systems