Without a dominant proprietary solution and with EJB in disarray, the software industry has a significant vacuum in the Java persistence solution market. Many are looking to the next best standard. With the Java Data Objects (JDO) 2.0 specification under way, the timing is right for JDO to seize this opportunity.
by Bruce Tate
Mar 11, 2004
Page 3 of 3
The Time Is Now for JDO
So here we are. EJB CMP is all but dead, since the major vendors are not supporting it with nearly as much fervor as before. No proprietary solution reigns supreme. Only JDO supports transparent persistence. Only Hibernate seems to be gathering momentum in the open source community, beyond simple POJO frameworks. That leaves a significant vacuum in this market. With the JDO 2.0 specification under way, the timing is right for JDO to seize this opportunity.
Here's what it must do to take advantage:
Finalize the 2.0 specification quickly. If it takes the JDO expert group as long to get 2.0 out as it did 1.0, it's dead. Right now, the 2.0 spec is scheduled to be delivered this year. It mustn't slip.
Address OR mapping. The primary obstacles to OR mapping in a JDO specification are no longer in force. Specifically, no proprietary OR mapping solution is dominant, and relational database vendors don't face any real competition. JDO 2.0 will include OR mapping support.
Embrace SQL. JDO needs a broadly accepted standard that addresses the needs of its community. JDOQL can still be supported for non-relational frameworks, but it won't ever be a mainstream language. Hibernate shows that an SQL dialect can succeed in a persistence framework. Right now, SQL is a possibility as a pluggable query language. SQL (or a close derivative) should be included in the overall standard.
Separate implementation details from the specification. Don't give customers another reason to reject JDO. Bytecode enhancement doesn't need to be a problem. Let customers choose JDO for its benefits and then choose bytecode enhancement where they feel it makes the most sense. The JDO 2.0 spec will no longer mandate bytecode enhancement. The JDO expert group will gain the biggest benefit from allowing frameworks like Hibernate and TopLink to participate in the standard.
Don't push binary compatibility. For most of JDO's potential customer base, it's not an issue. Few other J2EE standards enforce binary compatibility. Binary compatibility gets in the way of other important aspects of the spec. It looks like JDO 2.0 will make binary compatibility an optional feature, which existing vendors will continue to support.
Get big-name support. From the very beginning, lack of a big-ticket vendor has been a critical limitation for JDO. Oracle or IBM would be ideal. SAP also has a JDO implementation, and it is increasing its involvement with the JCP. Right now, TopLink and Hibernate appear to be strongly considering support of the JDO 2.0 standard. Either or both would go a long way toward relieving customer concerns that JDO is a small-time player.
Like most Java developers, I feel that 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. Others agree. It's starting to show in the press, and beyond:
I understand that one of the flagship JDO vendors, SolarMetric, is experiencing outstanding success, with two consecutive quarters of growth.
With an emphasis on better, lighter solutions, other vendors could well follow suit. The economy is once again growing, creating a great atmosphere for a new successful standard. Developers are hungry for persistence frameworks again. My "Java Persistence Strategies" class at the No Fluff, Just Stuff Java Symposiums is experiencing tremendous growth in enrollment, and people are talking about JDO again. If JDO doesn't step into this vacuum, someone else will.
Bruce Tate is the author of four books, including Bitter Java and Bitter EJB. He's an independent consultant who has worked with FedEx, TheServerSide, IBM, and BEA. He is the founder and president of J2Life, a company specializing in design reviews. .