Re: Need to learn J2EE and friends

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 06 Sep 2011 19:01:29 -0400

Message-ID:

<4e66a659$0$306$14726298@news.sunsite.dk>

On 9/6/2011 5:20 AM, Arved Sandstrom wrote:

1. As you begin teasing apart what a J2EE/Java EE application does, do
keep in mind that at their core these API families are 95 percent about
writing web apps. Plain and simple. Whether it's the Struts framework
building upon the Servlet API in the web tier, or session beans in the
services layer that encapsulate your business logic and provide
scalability and lifecycle management, it's all about scalable and
distributed servicing of requests.

6. "Enterprise" in "J2EE" or "Java EE" or "Enterprise Java" means "web".
Official documentation may not put it quite so baldly, but it's
basically all about handling HTTP/HTTPS requests from web browsers, or
SOAP requests coming in over HTTP/HTTPS for a Java web service.

The other main non-negligible input mechanism is messaging (JMS, or Java
Message Service).

There are obviously some other aspects to "enterprise", like being able
to talk to other systems like an EIS (you'll see the Connector
architecture discussed in the tutorial). But fundamentally it's about
being a web app.

I would say that about 50% of Java EE is by nature web oriented, but
>80% of Java EE apps have a web interface (I am not counting desktop
apps using SOAP/HTTP as being web here - if we do it would be >95%).

It is perfectly valid to write desktop apps in Java (using Java/IIOP or
SOAP/HTTP) or .NET (using SOAP/HTTP). It is just relative rare out in
the real world (even though I actually know a lot of examples, but
I do not expect that to be representative of the world).

Arne