Servlet vs EJB concept question
Posted on 2001-07-12
The chief architect where I work is using Weblogic solely for serving servlets (and jsps). They've written a large jsp tag library for database connections/queries/pooling as well as utilities for mail, etc., etc. At the moment the system is suffereing quite severe performanace problems. We're using Oracle as the database backend and from the looks have several quite competant dba's looking after the database.
I raised the question as to why all the work was being done by servlets when we should be using servlets solely for request handling, jsps simply for display logic and all the real work done by Session beans (Model 2 framework?). His reply (there were some language barriers) was something along the lines of "so much database logic and data", etc which sounded like he basically meant it was too much work. There are around 200 database tables in use.
I've always thought that the idea of the middle tier was to encapsulate all the business logic seperatly from the presentation while also providing significant scalability and performance benefits. But taking a second look at this it also makes sense that coding the queries and logic straight into jsps (esp. with tag libraries) makes it a lot less work for the same results. And in business, less effort = less money + quicker results which is definitely the driver in this organisation.
My question is basically what are the arguments for spending the extra development effort coding session beans to handle all the business logic as well as 200-odd classes to represent the entities, etc. when the same output can be produced by coding jsps just as you would with asp, cold fusion, php, etc.
I'm really looking for a decisive argument where the benefits are tangible and hard to ignore. More comments the better though...