cloudjun

1. Dependency Injection 

EJB3.x --Can inject anything in the container including EJBs, data sources, JMS resources and JPA resources 

Spring --Can inject almost anything including lists, maps, properties and JNDI resources. 

2.Transaction Management 

EJB3.x --Works right out of the box, but only JTA is supported 

Spring --Have to configure it to make it work, but supports a number of strategies including JTA, JDBC and Hibernate 

3. Persistence 

EJB3.x -- Tightly integrated through JPA. JPA is an API not an implementation. We could use JPA with different vendor persistence ORM implementation like Hibernate, Eclipselink (recommended by Oracle for EE6), Toplink (only available of JEE5 and less)

Spring --Framework support for JPA, Hibernate, JDBC, iBatis 

4. State management 

EJB3.x --Robust support through Stateful Session Beans and Extended Persistence Context 

Spring --Indirect support dependent on web container session management 

5. Web services 

EJB3.x --Seamless support for JAX-WS 2.0 

Spring --Poor direct support, best integration available is via configuring XFire for registered beans. 

6. Messaging 

EJB3.x --Supported out of the box through Message Driven Beans. 

Spring --Need to add configuration for message listeners. However, JMSTemplate adds nice abstraction over JMS. 

7. AOP 

EJB3.x --Simple but limited support through interceptors. 

Spring --Robust support through AspectJ and Spring AOP alliance. 

8. Security 

EJB3.x --Integrated support for declarative and programmatic security through JAAS. 

Spring --Must add and configure Acegi security. However,support beyond JAAS is possible through Acegi. 

9. Scheduling. 

EJB3.x --Simple scheduling possible through EJB Timer service 

Spring --Must add and configure Quartz for scheduling. 

10.Remoting 

EJB3.x --Integrated support through Session Bean remote interfaces. Supports distributed transactions and security. 

Spring --Remoting support may be added via configuration. Remote transactions and security are not supported. However protocols other than RMI such as Hessian and Burlap are supported.

11. Server Container Services: 

EJB3 run inside an EJB container inside an application server as middle ware components and there for provided all the application server features. 

Spring beans run inside a web server there for limited to the web server abilities.

 

I have been playing with Google Application Engine for the past two days, trying to build a tool for my wife, so that she can get notification emails when, for example, a price drop happens for the burberry handbag she always wants from neimanmarcus (did I spell it right?) website.

Well, I kept encountering technical issues with GAE.

1) When working with the GAE plugins in eclipse, it seems that I cannot include any third party external jars into the project. It will compile corretly, but throws a classnotfoundexception in runtime, when the third party jar is going to be used. My alternative is to include all the source files for the 3rd party jar into the project.

2) No thread creation on the server side. It looks like GAE does not allow thread creation inside the server side servlet. Because my application needs to monitor a website on an interval base, I planned to spawn a thread to achieve that, although I would do it differently if I have total control on the backend. It gives me an access exception (if I remember it correctly) when I tried to do so.

3) Because of #2, I have to move the polling part inside the same thread which receives the async request on the server side. After maybe 30 seconds (the thread sleeps for 20 seconds), a DeadlineExceededException is throw. I think GAE does not allow a servlet thread to be executed more than 30 seconds.

With that, I decided not to build this application on GAE. I am not saying GAE is bad, but it just does not meet the technical requirement for this specific type of application.