Java session focuses on Web app obstacles

Las Vegas -- Obstacles to developing Web applications was a critical issue on the minds of Java developers at TheServerside Java Symposium on Thursday.

Web application development technologies include scripting offerings such as AJAX (Asynchronous JavaScript plus XML) and frameworks such as JavaServer Faces, Struts and Tapestry.

Audience members and panelists, during an opening interactive session, focused primarily on issues with AJAX, although a need to boost programmer productivity in Java in general also was cited.

One attendee predicted AJAX and POJOs (Plain Old Java Objects) would make a big difference in building of Web applications. Also, symposium panelist Patrick Linskey, an engineer at BEA Systems, predicted that in 2006, someone will find a meaningful way to wire up a server-side AJAX framework with a non-browser-based client side. "That's where I think Web 2.0 starts to get really interesting," said Linskey, who had been the CTO at SolarMetric, which was acquired by BEA.

But another audience member questioned the viability of running multiple AJAX applications in a browser, which could result in crashes. "How much can you load into a browser?" the attendee asked.

A rush to AJAX also was a concern. "We've noticed major architectural decisions that were very poorly thought out," because of rushing to AJAX, an audience member said.

AJAX also lacks good tools, according to panelist Cedric Beust of Google. "Writing AJAX applications is a lot more challenging than writing client applications mostly because of the tools," Beust said.

Panelist Hani Sulieman, CTO of Formicary, said he favored the desktop. "In terms of richness of experience, I think the desktop is way superior to the browser," Hani said.

The Ruby on Rails open source Web framework featuring AJAX did not get a wholehearted endorsement, with an audience member saying it lacked maturity. The quality of error messages is nonexistent, for example, the audience member said.

AJAX technologies are not new, said Craig McLanahan, Sun Microsystems staff engineer, in a subsequent presentation at the conference. But what is new is a synergy between the ability to have XMLHttpRequest implementations in browsers and robust DHTML (Dynamic HTML) and JavaScript implementations, he said.

Speaking on the issue of Web frameworks, developers face five principal issues in choosing one, according McLanahan said. These include:

* Modeling of page navigation decisions,

* Provisions for accessing model-tier data,

* Representations of static and dynamic markup,

* Mapping incoming requests to business logic, and

* Whether the framework has a user interface component model.

"What's interesting about Web frameworks in particular is when you step back from all the details, most of the frameworks are dealing with exactly the same set of issues," McLanahan said.

Providing updates on some noteworthy frameworks, McLanahan said JavaServer Faces 1.2 is almost final and cleans up incompatibilities with JavaServer Pages technology. The Shale 1.2 framework is being readied for released in alpha form, he said.

Web application frameworks have addressed usability limitations in low-level, standard APIs and encouraged better architectures by separating concerns, McLanahan said.