Re: Beginning J2EE

Chris ( Val ) wrote:


Sun's App Server, based on the open-source Glassfish, is full featured. It
has a similar "enterprisey" feel to, say, IBM's WebSphere. It is really,
really full featured.

Working with enterprise-class application servers, one must shift from being a
programmer to being a systems master.

I started my JEE (then "J2EE") learning on Tomcat, then Tomcat + Apache HTTP
server. (httpd has some amazing capabilities.) This gets you going with
servlets, JSPs, multi-tier architecture and DAO stuff, plus is plenty
challenging when you integrate the whole thing (browser to RDBMS). At this
point one is not dealing with EJBs, BPEL, thread pools, anything more than
rudimentary LDAP or DB connection pooling. Most of what one can do as an
individual practitioner, including SOAP Web services, fits into the Tomcat (or
other servlet container) mode.

Ambition sets in. We're serving 100,000 requests a day. We've got a
terabyte-scale data store. We're load balancing, transaction managing, pool
tuning, queuing, abstracting common business practices into independent
components, data mining, and placing every higher demands on our information
(not just data) systems. We've got departments, data centers, budgets. It's
not just about the software - we need to integrate operations and business
goals in actual production. Now the full-blooded application servers like
JBoss, Geronimo and Glassfish come into their own.

As practitioners we need to encompass the operations standpoint and master
issues of deployment and real-world service guarantees. I suggest using all
three of the major free app servers (again, JBoss, Geronimo, Glassfish) for
learning. Pick a favorite after experience.

Many paying clients do not pick one of those, but an offering from the likes
of IBM, BEA, Oracle or, yes, Sun. These guys do support the open-source and
standards initiatives, so there will be plenty of skills applicability from
your use of the freebies.

--
Lew

--
Lew