With the rapid growth of the Internet, distributed Web-enabled applications are becoming popular. One of the most commonly used architectures for development of such applications is CORBA, which provides a platform, location and an implementation-language-neutral architecture for the d...

Online stores are the new, next-generation, 'revolutionize the world as we see it today' way of doing business. In the context of business transactions, online stores use the global Internet to facilitate purchase and sale of goods and services. The ability to support online sales is a...

Data-driven - or data-aware - components are objects that listen for changes in the data and notify other data-driven components that have requested to listen. This design is a powerful means of maintaining an application throughout not only the first development cycle, but also subseq...

JavaBeans, now in its third year, is proving to be a powerful component model. Whether it's the Java e-commerce framework or the Java platform for the enterprise, JavaBeans is at the heart of many new and exciting technologies. The JavaBeans model provides a framework to build, customi...

Hello, and welcome to electronic Java! In this column we'll examine the role of Java in the fast-growing world of electronic commerce. We'll also look at how the different components of the Java 2 Platform fit together to create complete enterprise-level e-commerce applications. This c...

If you haven't tried it yet, Swing is Good. For those of us who've had to wrestle with the java.awt to build GUIs, Swing is a much simpler and more powerful alternative. With its "coming soon" status in the com.sun.java.swing classes in JFC 1.0 upgraded to "officially bl...

Java scripting support in VRML2/VRML97 set the stage for experimenting with multiuser distributed virtual environments on the Internet, hereafter referred to as televirtual, or TVR, environments. A typical minimal configuration of such a system would include a few VRML2 browsers, downl...

Since the introduction of the Java Foundation Classes (JFC), Java applications have been able to be implemented using a rich set of window components. These components - called Swing - along with customizable "look and feel," allow applications to be implemented without relyi...

A Tree for All Occasions The Java Foundation Class, also known as Swing, in addition to augmenting, enhancing and generally implementing platform-independent replacements of AWT components, added the JTree class to its repertoire of new GUI components. Swing's JTree supports a Windows ...

One of the primary design goals for Java is the idea of "write once, run anywhere." Java is therefore an ideal language choice when faced with the challenge of developing a platform-independent application.

In creating the HotScheme interpreter (JDJ Vol. 4, Issue 1), we decided to employ functional programming concepts to Java, our implementation language, whenever it was practical. Functional programming has a number of advantages over more traditional procedural code, which we will enum...

The Challenge of Java Integration with Legacy Assets Organizations are developing a new class of electronic business applications, using Java to capture new business logic. In some cases these e-business applications ,have gone beyond just successful deployment to redefining the compet...

In recent days, CORBA has fast become a standard for the development of distributed applications. A CORBA application may consist of one or more CORBA server objects and many clients who connect to these servers. A CORBA server object makes itself available to the client by registering...

Persistence is our way to fight the decay of time. We take pictures and film events in order to remember, review and analyze them. We freeze perishable products in order to preserve or transport them over long distances. And in much the same way, computer users save ideas and programs ...

In the previous two parts of this three-part article (JDJ Vol. 3, Issue 12 and JDJ Vol. 4, Issue 1), we looked at the fundamentals of programming with Java I/O streams and the various APIs they can be used with. This month we'll conclude this article by discussing the concept of writin...

Program correctness may be viewed as proof that the computation, given correct input, terminated with correct output. The person who invokes the computation has the responsibility of providing the correct input, which is a precondition. If the computation is successful, we say that the...

Do your Java applets and servlets need to read and write files stored on a server elsewhere in the network? If so, you need NFS, a fast file-access protocol that is destined to become a standard for file access over local area networks (LANS) and the Internet.

This article describes our use of design patterns to create an interpreter in Java, and shows how it can be built in a "pure," object-oriented fashion. .The patterns we use are from Design Patterns: Elements of Reusable Object-Oriented Software by Gamma, Helm, Johnson and Vli...

As Java takes a leap toward the next generation of enterprise computing, enterprises get ready to deploy large-scale business applications using Java. This article describes how the new Enterprise Java-Beans (EJB) technology from Sun Microsystems can be instrumental in building distrib...

Last month's issue (JDJ, Vol. 3, Issue 12) covered the basic concepts of programming with Java's I/O streams, such as the difference between byte and character streams, the various stream classes, the concept of stream chaining and more. We'll conclude the subject this month by lookin...

It's true that you don't need a computer degree to know how to program. However, to do it with the kind of quality that allows for easy maintenance and change is another matter. As we all know, based on Software Engineering (SE) principles, a software product's life cycle consists of a...

Hypertext is wonderful. It allows the Webmaster to link from any page to millions of other computers all over the world. Unfortunately, the Web pages you find will only have the links that were placed by the Webmasters. What if you want more information about a word or a phrase on a pa...

This is the first in a two-part series on Event management in large distributed applications built on top of Enterprise JavaBeans (EJB). This installment will cover the architecture and the implementation of a local (single VM) version of the event distribution system. The second artic...

Sometimes Java applets continue their execution even after the page that contains them is no longer visible. Run a few of them and your computer will slow down dramatically. If you continue you might need to reboot the system to avoid a crash. So you disconnect, reboot, reconnect and ...

When you see the words Java database application, you probably start thinking about enterprise-level solutions with multitier architectures and distributed deployment. But Java is a great general-purpose, object-oriented language and thus a good choice for developing smaller scale, sta...

Most programs use data in one form or another - as input, output or both. The sources of input and output can vary from a local file to a socket on the network, a database, in memory or another program. Even the type of data can vary from objects and characters to multimedia and more.

The Internet is rapidly evolving from a static, stateless, information-exchange medium to a dynamic transactional medium that offers new opportunities to change how we do business. To exploit these opportunities, leading-edge independent software vendors and corporate IT organizations ...

So I get to the office in the morning and see Mr. Job Prospect's résumé lying on my desk. That gives me about 20 minutes to think of interview questions I'd like to ask him. A quick scan of the résumé reveals that he's done some serious work in Java that includes programming with JFC, ...

A layout manager is an object that positions and resizes components within a display area according to a specific algorithm. The Java 1.2 AWT package provides 10 layout manager classes that can be used to accomplish this task. Each has a defined set of behaviors that organize component...

We all know what AWT is. We know that AWT 1.0 is simple and easy to use. It's compatible with the old versions of the Web browsers, but has an inefficient event-handling model. The events are received by the components, which handle or ignore them. Worse, if you want to add a small fun...

There's a problem faced by all Web designers: making a menu look interesting without taking forever to load.

Henry Ford revolutionized manufacturing with the first automated assembly line in 1913, incorporating the latest time-study theories to make Model T's flow through the system "like the flow of water through a pipeline." His engineers and foremen repeatedly analyzed every task...

Persistence in Enterprise JavaBeans is encapsulated in the notion of EntityBeans. This article describes bean- and container-managed EntityBean persistence and the relative merit of these techniques with respect to portability, productivity and performance.

As Java matures, new sets of behavior added to its API allow developers and programmers to write more sophisticated programs with less difficulty. This article focuses on collections API, a new abstract data structure that will be a part of the core Java Development Kit (JDK) 1.2 API. ...

Developing and maintaining distributed business applications is hard. As if writing business logic weren't hard enough, enterprise application developers have also been saddled traditionally with the daunting task of implementing transaction management, persistent state management, thr...

Java servlets provide a new way to develop server-side solutions. They provide the features of traditional CGI scripts with the additional benefits of efficiency and portability. Currently, major corporations are making the migration from CGI scripts to Java servlets. As a result, the ...

This article tries to take the mystery out of the black art of developing layout managers. Much of the coverage in books and magazines typically centers on trying to wrench the complicated GridBagLayout into submission or demonstrates the development of a layout manager with virtually ...

Version 1.0 offered developer productivity, ease of use and powerful features. Now, with a new high performance compiler, connections to more enterprise systems, team programming support and exploitation of the latest in Java technology, VisualAge for Java, Version 2.0, looks like a gr...

I'm starting my computer. I'm waiting for the operating system to be loaded. Now I can see the icons of my favorite applications. They're aligned on my desktop and in the same positions I left them.

Java brought garbage collection to mainstream programming. Never before have commercial software developers been so aware of the need and benefit of using a collector. Notwithstanding, the benefits of garbage collection in Java are far from being completely realized. As larger and more...