EJB was created almost 10 years ago to solve the component needs of application developers. Since then thousands of successful applications have been written and deployed using this technology. Although I don’t do much with EJB nowadays as I have other responsibilities at JBoss, I still wonder how it is doing in the industry. Recently, I became privy to various bits of knowledge that EJB is still going strong and maintaining its dominance in Java application development. Consider this job trends graph from indeed.com:
Over 3 years EJB jobs have remained pretty much constant. This is very encouraging news considering recent Rod Johnson propaganda. EJB really did not have an alternative in the Java space until 2004/2005 when Spring started to be known and popular. It is very interesting to see that although EJB has had a serious competitor, it has maintained its dominance in Java application development over the years. You could even extrapolate from these numbers that EJB is an upper bound on the number of Java component jobs out there and that Spring has only recently matched this. This is proven by the fact that the Spring and Java graph trends are the same since they converged 6 months ago.
This trend pretty much correlates with download numbers I posted on our EJB implementation awhile back on TSS in June 2007.
I can give you a few from two perspectives:
downloads on sf.net for JBoss and Hibernate projects related to EJB3 and JPA:
* Downloads of a standalone distribution of the JBoss EJB3 project since 10/2004: 183199
* JEMS installer which bundles EJB 3.0 (not same as JBoss Appserver download): 201923
* JBoss 4.2 which bundles EJB 3.0: ~65000
* JBoss 5 betas which bundles EJB 3.0: ~80000
* Hibernate’s JPA implementation: 135269
* Hibernate Annotations (which is JPA based): 202561
So, total downloads solely related to JPA: ~337K
Total downloads solely related to EJB3: ~550K
Total EJB3 + JPA related downlaods: ~ 887K
Compare that to Spring 2.x downloads: ~600K
Spring 1.x downloads: 946K
Hibernate 3.x downloads: 1445K
Hibernate 2.x downloads: 495K
Now that’s just JBoss. You also have Glassfish, Open JPA, Oracle, and now Geronimo communities not included in these numbers.
Also, my EJB 3.0 book has been out a year and has sold ~12K copies +/- a thousand (haven’t gotten check yet from last quarter).
So, all and all I think there is pretty compelling evidence that EJB3 and JPA has momentum.
Its hard to continue any analysis on JBoss specific download numbers as we basically encourage our user base to download JBoss 4.2.x or 5 as it is bundled with our EJB3 implementation.
There’s some other encouraging numbers as well. In 2005 I was offered by O’Reilly to take over Richard Monson-Haefel’s EJB series. “EJB 3.0, 5th Edition” was published in May, 2006. Even after being out for almost a year and half, sales are still going strong. Just last quarter we sold 1700 copies, very good for a technical book. When I went to Krakow in October, I also found that my book had been translated into Polish. I believe its also been published in Chinese. All indicators of broad adoption by the technology.
So, as you can see, even after almost 10 years, EJB is still going strong and maintaining its dominance. With the emergence of Seam and Web Beans being incorporated into EE 6, I predict this trend to continue.