Java vs J2EE vs... huh?

[Joe Vahabzadeh]

Ok, this is probably going to sound like an incredibly dumb question, but whenever tried to look up definitions on the web, I got descriptions that sounded more like a sales pitch than something that told me what I needed to know.

What is the difference between being a Java developer and a J2EE developer?

I mean, I've done a few years of Java software development, but when someone asks me if I've done J2EE, I'm sort of at a loss for an answer. What exactly do they mean when they're asking that?

And then, what exactly are EJBs, other than bits of code that have already been developed? Does that somehow tie in with J2EE (I've never seen the questions asked separately)?

Thanks in advance for clearing things up for my terminologically deficient head!
[ November 06, 2005: Message edited by: Joe Vahabzadeh ]

[Campbell Ritchie]

EJBs-don't know. I suspect they are some sort of Enterprise variant of Java Beans.
But I haven't got round to using beans yet, so I am afraid I cannot help you.

Most people starting Java use the appropriate J2SE JDK (= Java 2nd version Standard Edition . . . Java Development Kit), but it has a multiplicity of names. That is probably what you are using now.
The Enterprise Edition (J2EE), which I have not yet used either, is a version of Java with expansion of the API to include classes likely to be particularly of use to large companies.

So there is probably not much difference between a Java developer's job and a J2EE job.

[Peter Rooke]

EJB's (GIYF)
The Enterprise JavaBeans specification is one of the several Java APIs in the Java 2 Platform, Enterprise Edition. The specification details how an application server provides server-side objects known as Enterprise JavaBeans, or EJBs, with:* remote communication using CORBA* persistence* transactions* concurrency control* events using JMS (Java messaging service)* naming and directory services* security* deployment of components in an application server.

So J2EE is a specification, from Sun. Sun and other companies provide J2EE application servers (software servers) that meet the spec (and add some other features). Here's a few servers: WebSphere (IBM), WebLogic (BEA), Sun (Sun ONE).

There are forums on JavaRanch for J2EE technologies, and servers.

So there is probably not much difference between a Java developer's job and a J2EE job.

[Ben Wood]

Joe,

I'll try to help simplify, but I think there is a little vagueness about what J2EE means to different people.

First off it is more than just EJBs (in fact some J2EE developers might not use EJBs at all). EJBs are a sort of transactional data object which is persisted as a row in a relational database and are only appropriate in certain cases depending on what you're trying to do. In my experience EJB can be a case of sledge-hammer-to-crack-a-nut and I think of all J2EE technologies they should be left til last when learning.

J2EE in general covers things like Java Servlets and other web-stuff like JSP pages. It gives you a framework for developing things like web-applications which may be connected to back-end objects and databases.

If I were you I wouldn't get too tied up in the term J2EE, but instead take a peek at servlets, JSPs and also the Java containers in which they run (for example Apache Tomcat). You might also like to read up on web-services and take a look at JDBC for querying databases. This should give you a feel for what can fall under the umbrella title of J2EE.

So there is probably not much difference between a Java developer's job and a J2EE job.

...oh, and I'm afraid there is!
[ November 09, 2005: Message edited by: Ben Wood ]

[Joe Vahabzadeh]

Ultimately, though, boils down to being another set of functions, APIs, or whatever, to learn, that work specifically with web-interaction.

I guess technically, I do have some J2EE background, as I've done JSP work, as well as having worked a bit with the RMI coding between our client/web side stuff, and server side functionality (and of course doing a bunch of the server-side development), though I have NOT worked with the J2EE application servers like Weblogic, WebSphere, etc.

The terminology tends to kill me, though!

[Scott Selikoff]

My 2 cents... EJBs are nothing like JavaBeans and should not even be used in the same sentence except as a constrast. Ignore the naming. EJBs are about as much like JavaBeans as mud is about glue.

[Arun Kumarr]

I believe when you meant java Developer you meant Core java, is it?
Here is what lil' i know.
J2EE Developers, know how to make their J2EE component work along with java.
Say you write an EJB and it may have complex/simple java code in it.
The point is J2EE developer knows how to write XML files which assists in deploying the EJB, Works with Servers, handles Deployment issues.

Java Developers on the other hand deal more with Core Java API's.

To find a difference between a guy who has worked for 2 years in core java and a guy in J2EE from the beginner level ask them about, say the Collection API's. A java developer knows better than the J2EE Developer.

But that's not hard and fast!!!
[ November 11, 2005: Message edited by: Arun Kumarr ]