Wednesday, June 28, 2006

Spring Vs EJB

In quite a few design brainstorming sessions, the debate between Spring and EJB results in a deadlock. There are developers who are damn passionate about Spring and hate EJBs. Let’s have a look at the main important differences between the two:

1) Distributed Computing – If components in your web-container need to access remote components, then EJB provides in-build support for remote method calls. The EJB container manages all RMI-IIOP connections. Spring provides support for proxying remote calls via RMI, JAX-RPC etc.
2) Transaction Support – EJB by default uses the JTA manager provided by the EJB container and hence can support XA or distributed transactions. Spring does not have default support for distributed transactions, but it can plug in a JTA Transaction manager. Both EJB and Spring allows for declarative transaction demarcation. EJB uses deployment descriptor and Spring uses AOP.
3) Persistance – Entity Beans provide CMP and BMP strategies, but my personal experience with these options has been devastating. Entity Beans are too slow!!!..They just suck..
Spring integrates with Hibernate, IBatis and also has good JDBC wrapper components (JdbcTemplate).
4) Security – EJB provides support for declarative security through the deployment descriptor. But again, this incurs a heavy performance penalty and I have rarely seen projects using EJB-container managed security.