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Being persistent

Posted by daniel on March 12, 2004 at 8:32 AM PST

Is it time to rally round Java Data Objects?

Bruce Tate has some thought on the future of Java Data Objects (JDO's). In
Also in Java Today
, we link to his DevX piece For JDO, the Time is Now. Bruce looks at future options for persistence frameworks. He notes that "Hibernate is prompting interest in transparent persistence. It's a strong solution for medium-sized and smaller applications, especially when the database schema is directly under the control of the development team. Still, many larger customers will not consider an open source alternative, especially a nonstandard one".

Bruce doesn't have nice things to say about EJB as a solution. His recounting of history is that "The top Java vendors and insiders pushed EJB hard, and the industry bought it. EJB introduced container managed persistence (CMP) as one of Java's first full-service persistence layers. No one could really make CMP work, but few could resist the EJB hype, which was at a fever pitch. [...] Contrary to its hype, EJB complicated programming, seldom worked, and scaled poorly. Eventually, most developers cracked and conceded that they were in over their heads."

So that brings us back to JDO. The first run at the JDO spec took three years and, in Bruce's view, didn't deliver the most important piece: OR details. ". With the JDO 2.0 specification under way, the timing is right for JDO to seize this opportunity." Bruce outlines the action items that include finalizing the 2.0 spec quickly, addressing OR mapping, embracing SQL, separating implementation details from the spec, not pushing binary compatibility, and getting big name support. He concludes, "J2EE does need a standard for transparent persistence, and I think that JDO 2.0 has the best chance to be a reasonable alternative to entity beans."

Today we also link to the ONjava article MVC Heresy with SQLTags . This grew out of an email exchange in response to Sue Spielman article where she wrote "The JSTL includes a number of actions that provide a mechanism for interacting with databases. The previous sentence should, at a very minimum, send up a red flag in your architectural visions." She went on to explain that although this was a bad idea, the JSR-53 expert group said they were included in response to the community. Steve sent me an email on SQLTags and this article summarizes the use of "database schema as [a] tag library".

John Reynolds responds to Bruce Tate's JDO piece in today's Weblogs . In Make JDO the "P" in CMP he points out "Solutions that already incorporate Entity Beans would be painfully expensive to rearchitect as JDO solutions." After addressing some of the details in Tate's article, Reynolds writes, "All in all, I am delighted at the possibility of a JDO resurgence, but I hope that it expands to embrace fixing EJB CMP rather then just replacing it."

Attention webloggers There continues to be some sort of glitch in the system that is being addressed. For now to create a new
entry you should login and then go to the weblog home page.

In today's Projects and Communities , the Java Games community wiki hosts the beginning of a comprehensive tutorial Dr. Strangegame, or How I Learned to Love Game Creation .

There is a discussion on Andy Lester's weblog of The world's two worst variable names. His nominees are data and data2. Respondents add their favorites.

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