Just read an article by floyd marinescu about the new features in j2ee 1.4.( part 1 and part 2.) It’s a good article, although i would have liked some code examples.
The biggest improvement is probably the inclusion of all the api’s required for web services, but also the EJB improvements are usefull. I didn’t know ORDER BY and aggregate functions such as COUNT and SUM were missing, how can you live without them? I mosly use (p.o.) JDBC and DAO’s so i’m not too familiar with EJB-QL. Also a timer-service has been added to the J2EE container, although if you want to do some real complex scheduling this may be a better solution (obviously i’m a bit biased here ;-)
It’s also nice to see that JSP’s have been made easier by the new expression language and the tag files, which allow you to implement a tag without creating a class for it. (I’ll have to try it, maybe i’ll like it enough to stop using velocity?)
Other improvements are the improved management and deployment support and the j2ee connectors have also been improved.