Blogging Roller

I decided that the only way to get a clue about pluggable persistence is to try and implement it, so that is what I did. I wrote a very simple JSP-based RSS aggregator with pluggable persistence via the DAO pattern. I implemented the persistence layer with both Hibernate and Castor and I used the RSS parser from Flock to parse RSS.

In the process I learned a lot about Hibernate and Castor. I am really impressed with Hibernate, but it is too late to go into any details. I do have time to say this: the Hibernate documentation is excellent, especially when you compare it to the incomplete hodge-podge of ad-hoc notes that comes with Castor. I did run into one snag that I have not yet worked around: Hibernate does not support CLOBs!

The aggregator is called, for lack of a better name, Ag. You can download Ag from SourceForge or just read the readme.txt.

Ag serves a number of purposes. I'll continue to experiment with Ag as I try to learn more about the advanced features of Hibernate and Castor. At some point, I'll probably merge Ag or some ideas from Ag into Roller. In the shorter term, I hope to use a portion of Ag as the example application for a chapter I'm writing on Data Access for WROX's new Professional JSP 2.0 book.