Have you ever wondered why you should use interfaces instead of abstract classes, or vice versa? More specifically, when dealing with generalization, have you struggled with using one or the other? I'll shed some light on what can be a very confusing issue.

Benchmarking any distributed computing middleware product is a complex task. Knowing how well a distributed infrastructure will perform under heavy load with a large number of concurrently connected users is a key factor in planning a development and deployment strategy.

The Java Platform Debugger Architecture (JPDA) provides a standard set of protocols and APIs at three levels that facilitate the development of a new breed of debugging and profiling tools. The inclusion of JPDA in the Java 2 SDK enables individual developers as well as commercial vend...

Essential to the development of complex systems are tools that help the developer locate, analyze, and fix problems. Debuggers provide support for this by letting a developer inspect the internal state of a program at runtime, as well as suspend and resume execution statement by statem...

Over the past decade the Internet has evolved from a research project living in the realms of academia and government to a global infrastructure for electronic commerce and digital communication that has sent the stock market on a roller-coaster ride to new highs (and lows).

Conditional compilation is not available in Java - and Java's platform independence is the cited (and largely justified) reason. Nevertheless, one valuable use of conditional compilation, which is to cleanly insert debug code into applications, is thereby lost.

The J2EE architecture is a great advance for developers. Its standardized framework defines and supports a multitiered programming model, freeing application developers to concentrate on solutions.

Last month in JDJ (Vol. 6, issue 1) we looked at the advantages of downloading servlets and JavaServer Pages (JSP) from a repository, for example, the same way a browser downloads applets. We described a simple implementation of this concept based on a service servlet and a custom ...

In May and July of 2000, Java Developer's Journal (Vol. 5, issues 5 and 7) ran a two-part article on how business rules can be implemented in Java. To recap, business rules are a formalized representation of the policies, practices, and procedures of an organization, describing how bus...

When Sun released J2EE to capture the growing e-business market, it changed Java from a language to an enterprise platform.

Smart card, Java workstation, and cryptography: these are all growing areas of interest in the computing world. There are programmers - from novice to expert - who know each of these technologies. But as the technology world becomes more intertwined, so too do these seemingly dispa...

The term deploy describes the process of installing the pieces of an application to a host and making whatever modifications are required to the host environment so the application runs correctly without further modifications. A patch is a group of Java class files, one or more documen...

Starting about 3.5 billion years ago with bacteria, nature em- barked on the grandest of all algorithms: the evolution of highly complex and dynamic machines capable of interacting with and adapting to their environments in order to solve problems. We know these machines as plants and ...

JavaServer Pages is a hot technology right now, as all Java developers are aware. In its simplest explanation, JSP provides the ability to combine Java code with HTML content to achieve dynamic content output from a single source file. Behind the scenes the JSP is compiled into a Java ...

Extremely large, complex software systems stretch the limits of modern design and implementation techniques. Agent-based computing is an approach to design and implementation that facilitates the design and development of sophisticated systems by viewing them as a society of independen...

Sometimes it's worthwhile to go back and visit your former projects. It certainly was for me - using presentation as a commodity to be deployed according to network configuration is the concept that resulted from my visit.

The Java 2 Platform, Standard Edition (J2SE technology) v1.3 for Linux means that Linux users and developers can take advantage of thousands of Java technology-based applications, from enterprise e-commerce infrastructure to client-side applications. It also opens up a huge emerging ma...

The world is abuzz with the promise of embedded systems, and hopes are riding high on the immensely popular Linux operating system. Its open-source model, easy customization, and popularity with developers make it an ideal choice for embedded systems. The recent flurry of Linux-powered...

Linux from its inception was written by programmers for programmers. In the years since, the GUI interfaces and other user-friendly items have raised the warm and fuzzy quotient to make Linux accessible to the casual user. However, the core idea remains: provide maximum support and usa...

If you think Linux is the choice of geeks only, think again. Many of the large software vendors are now shipping Linux versions of their software. In this article I'll take you through some of these product offerings. Be prepared, though: if you're new to this Linux world you're going ...

Numerous books and publications are available on the various technologies that support e-commerce on the Internet. As Java Servlets and JavaServer Pages (JSPs) emerge as a popular technology, a lot of material is being written about them. Most of this material focuses on programming mo...

All major and minor application server vendors heavily advertise the connection pooling functionality of their respective offerings. In this article I examine what's involved in developing resource pooling features from the perspective of a Java developer. I feel the subject is both gr...

During our last project we needed a logger but didn't want to develop our own, so we looked for third-party logging APIs. We found a few and experimented; one of them, log4j, far outshone the others. It helped us so much in tracing and debugging our problems that we recommended it for ...

To extend Java's concurrent behavior in a more natural way, in a more object-oriented point of view, we propose an extension to Java's concurrency model that will emulate Eiffel's separate statement. (Eiffel is an object-oriented language with a comprehensive approach to software const...

Given the popularity of the Java software application development platform and the market potential for embedded devices, there's a need to understand how programs can take advantage of the use of Java for embedded application development. This article investigates three Java tools tha...

Serialization in Java is an operation in which an object's internal state is translated into a stream of bytes. This binary stream or image of the object is created in an operating system-neutral network byte order. The image can be written to a disk, stored in memory, or sent over a n...

Most application architectures are organized into tiers. Presentation, business logic, and data combine to form a complete solution from end to end. The data tier is where your application gets and stores data that's used throughout the application. It could be accessing relational- or...

The design of the Java language has done much to overcome the limitations of C and C++. However, testing and debugging continue to account for much of the cost of developing Java applications. Once you've deployed a Java application, it's even more difficult and costly to fix software ...

Server-side Java continues to gain ground as the technology of choice for powering dynamic Web sites, but the goal of using Java to separate presentation from business logic has been a tough one to achieve.

Imagine this scenario: you've written all the appropriate interfaces and implementations for an EJB and now it's time to use it in client code. First you get a bean reference. Everything is simple enough: use JNDI to get the home interface, call a create method on it and catch all the ...

On the Web it's about three things – speed, reliability and scalability. Does your Web site respond quickly? Does your Web site always respond quickly? Does your Web site always respond quickly when it's being used by tens or hundreds of thousands of users?

Popup menus, the extremely functional components available to the Java developer, allow developers to provide menu capability without the inclusion of a full-blown menu system (i.e., MenuBar, Menus). From a user interface perspective, however, they're not intuitively accessible. The po...

The Oracle Internet Platform embeds the Oracle8i JVM within the Oracle8i database and Oracle Internet Application Server (iAS) as the enterprise Java engine for Oracle. This article explains Oracle8i JVM's base architecture, its support for J2EE APIs and its latest performance and arch...

One of the problems of highly distributed systems is figuring out how systems discover each other. After all, the whole point of having systems distributed is to allow flexible and perhaps even dynamic configurations to maximize system performance and availability. How do these distrib...

Increasingly, business applications are evolving into a client side that interacts with the user, and a server side that stores and retrieves data and manipulates it in various ways. The client side may run on a number of different hardware types including telephones, pagers and handhe...

JavaSpaces is a powerful Jini service specification from Sun Microsystems that provides a simple yet powerful infrastructure for building distributed applications. The JavaSpaces specification defines a reliable distributed repository for objects, along with support for distributed tra...

Two basic types of data - test and binary - are used in applications to create files such as documents, images, video, text and executables. Certain applications, however, may need to alter a file to make it available to other applications; for example, e-mail requires text and binary ...

Building large systems requires the difficult and time-consuming activities of elicitation and representation of software requirements. During these analysis activities, particular analysis abstractions emerge. These abstractions, called analysis patterns, represent reusable patterns f...

The Web is moving to wireless and Java is making it happen! How is a wireless environment different from the Web? What languages are used for wireless devices and what features do they have? Most important, what role does the Java 2 Enterprise Edition (J2EE) play in a wireless architec...

In just a few years the Java language and platform has become the technical approach of choice for building complex, distributed and Web-enabled applications across the enterprise. Thanks to its cross-platform runtime environment, object-oriented development model, and facilities for w...