Two Object Relational Mapping Projects Proposed for Eclipse

Hot on the heels of Oracle’s recent announcement of its proposed Eclipse project to support the Enterprise Java Beans (EJB) 3.0 specification, Versant, a data management company, has proposed an Eclipse initiative that appears to stake out the same territory.

The Versant proposal would provide an implementation of its object-relational mapping (ORM) technology that is 100 percent compliant with the EJB 3.0 specification (JSR 220) and the Java Data Objects spec (JSR 243), integrated with the Eclipse platform.

The Oracle project aims to build an open-source EJB 3.0 ORM tool that focuses on design-time tooling and supports deployment to any J2EE-compatible application server.

The Oracle project will be based on its Toplink mapping workbench, which is the design-time developer tool used for object-to-relational mapping, says Dennis Leung, VP of development in Oracle’s application server group. The project will not include the Toplink runtime, Leung says.

The Versant project, JSR220-ORM, will be based the previously commercial implementation of the Versant Open Access product, which is now open source. The Versant plan also involves tracking the changes to these specifications, so that as they merge in the future toward a common persistence standard, it will be fully implemented by this project. Additionally, Versant plans to provide visual development tools that facilitate round-trip engineering when using the JSR 220/243 approach to persistence.

Mike Milinkovich, executive director of the Eclipse Foundation, said in a statement that this kind of project overlap isn’t surprising, given the widespread interest in the Eclipse framework.

“Now that the proposals have been posted, we expect that the teams will discuss whether there should be a merger of the two or if they will continue separately,” he said. “This decision will ultimately be up to the developers, not the Eclipse Foundation.”

The EJB 3.0 spec is one of the key technologies in the upcoming Java 2 Enterprise Edition (J2EE) 5.0 release. EJBs constitute component architecture for the development and deployment of component-based business applications. EJB 3.0 is intended to make life easier for developers by implementing a simplified set of APIs, eliminating deployment descriptors from developers’ views and facilitating a test-driven environment. It includes, among other things, metadata support, EJB Query Language (EJB QL) changes, the proposed entity bean model and a new way of accessing the bean context and runtime environment.

Whether an actual competition exists between these two project sponsors remains to be seen. However, Versant reportedly believes that it has a leg up on Oracle because its proposal is based on the Versant Open Access product, technology that is already open sourced.

“Versant has been working on this project announcement for many months without any knowledge of Oracle’s initiative,” the company said in a statement posted to its Web site. “We look forward to finding areas where we can cooperate with members to bring this standard to the Eclipse community. Eclipse has several places where multiple projects are working on the same technology areas. We hope that a common ground can be reached and this does not have to be one of those.”

Oracle doesn't see the two projects as overlapping initiatives. "On the surface there appears to be overlap," says Leung, "but the approaches are very different. Our objective is to facilitate adoption of EJB 3.0 in the Eclipse community. Oracle's project is focused on JSR 220 (EJB 3.0) and proposes a vendor independent solution to support the specification, while Versant's approach takes an existing JDO proprietary product and is trying to add EJB 3.0 support to it."

Leung believes that Oracle is taking a more vendor-neutral approach, because the open-source project will be targeting the EJB 3.0 specification while supporting vendor specific plug-ins. He adds that Oracle has support from other "thought leaders" in the persistence space, including JBoss, Hibernate and Solarmetric, a leading JDO vendor.

Oracle released a full implementation of the spec in its Application Server EJB 3.0 Preview in March. That preview includes a set of software tools designed to let Java application developers dig into the new EJB spec. Also, Oracle has been a member of the Eclipse Foundation as an Add-In Provider for about two and a half years, Leung says. They currently provide a plug-in that allows developers who want to use Oracle platform to work with the Eclipse IDE.

"There is a great deal of renewed interest in the area of Java persistence, thanks to the direction of EJB 3.0 towards supporting lightweight POJO persistence, plus the decision to merge the JDO and EJB standards over time," Milinkovich says. "The Eclipse Foundation is very pleased that both Oracle and Versant decided that Eclipse was the right place to build the great tools necessary to attract significant developer awareness and adoption of this evolving standard. This is yet more proof that Eclipse is the innovation engine in today's Java tools arena."

About the Author

John K. Waters is a freelance writer based in Silicon Valley. He can be reached at [email protected].