Cash in on components

WEB SERVICES MAY represent the future of enterprise computing, but nothing is new when it comes to developing those applications: Success or failure still hinges on having the right tools. Thus it is no surprise that the component-based approach to software development — which accelerates the coding process, reduces the number of errors, and limits software maintenance — has become so attractive to companies that want to create Web services.

That’s where solutions such as WebGain’s Application Composer 2.0 come in. The latest release of Application Composer is a component-based assembly environment that allows developers to quickly and easily construct and deploy enterprise applications, including Web services.

The suite does not replace other development tools such as an IDE (integrated development environment). Rather, Application Composer is designed to link together and deploy the components that form an application or Web service after those components have already been created. Still, the suite proved to be a reliable performer with enough unique features to merit serious consideration by any enterprise concerned about speeding up development work.

One of the main selling points of Application Composer continues to be its use of “behaviors” for assembling Java-based components, including JavaBeans, Servlets, JSPs (Java Server Pages), and EJB (Enterprise JavaBeans).

In Application Composer’s world, each component can be associated with a specific behavior. When an event occurs to trigger that behavior, a predefined action is performed. For example, imagine an ecommerce application that has a customer log-in component. That component could have a customer record lookup as its assigned behavior, which would execute once a valid log-in was processed. In this way, behaviors are used to link together the components of an application.

None of that is new to Version 2.0. What is new, however, is a feature that allows developers to link enterprise applications to SOAP (Simple Object Access Protocol) services. Moreover, any SOAP service that has been defined with WSDL (Web Services Description Language) documents can be imported into the Application Composer environment prior to assembly.

Another new feature in Version 2.0 is expanded assembly support for EJB, which allows developers to easily construct and deploy EJB-based applications. Specifically, Application Composer now supports Stateful Session EJB, Stateless Session EJB, and Stateful Session Synchronization EJB via its capsules. As a result, enterprise developers can use Application Composer’s capsules to organize application components in a modular manner and vastly enhance the range of server-side functionality in their applications. Beta support for EJB 2.0 components is also included in this release.

Furthermore, Version 2.0 now boasts a component search tool, which allows developers to find pre-existing components from the ComponentSource Web site ( www.componentsource.com ), which can then be used in their applications.

New features aside, one of Application Composer’s chief selling points is its inclusion of third-party software that is aimed at speeding developers along. For example, Version 2.0 comes with a copy of Macromedia’s Dreamweaver UltraDev design application. WebGain supplies links between Application Composer and UltraDev. Developers can use the Macromedia Extension Manager to enable the Application Composer extensions, which are then accessible in UltraDev’s Insert menu.

WebGain also supplies a limited, development copy of the PointBase database for programmers who want to construct and test database-related applications on a development system. The included database is limited to 5MB and allows only a single connection at a time, but we still found it useful for application prototyping and testing database connectivity or read and write functionality.

The open-source JBoss application server is also included for development purposes. Programmers can use the reliable, solid JBoss to deploy applications, giving them a useful way to validate proper server-side functionality. Applications can also be deployed to other supported servers, including Jakarta-Tomcat, Bluestone, and WebLogic.

In our tests, we found the process of assembling applications to be very simple. We rapidly wired together several applications, selecting from a range of pre-existing components (such as credit card processing modules for our test e-commerce site and order processing components for our test btob environment). We were particularly impressed with how simple it was to import EJB and Web services into our applications and to define database connections. And Application Composer’s built-in debugger did a good job of trapping glitches during application testing.

Among the only notable drawbacks we found with Application Composer was its limited platform support. Currently, the assembly environment is supported only on the Windows 2000 and Windows NT platforms, although the company does have plans to expand the range of supported platforms in the near future. In the meantime, applications built with Application Composer on Windows can be deployed to other platforms, including Linux.

Another shortcoming was Application Composer’s lack of integration with any version-control solutions. That absence obviously makes it difficult for programmers to manage the various iterations of their software, which can be a particularly thorny problem in team-based environments. The only work-around solution is to track component versions outside of Application Composer. WebGain officials have indicated plans to offer version-control integration in the near future.

Those imperfections aside, Application Composer 2.0 remains a reliable, stable performer that handled our tests with aplomb. At $995, the suite is no bargain, but the principal value is in its unique behavior-based approach, which works wonders on unforgiving development schedules. And in the hotly contested race to the Web services finish line, that’s no small consideration.