推荐：门户portal系统的两个开发源代码

有两个产品: basicPortal和Liferay

http://basicportal.com/

http://www.liferay.com/

网上讨论:
http://www.theserverside.com/home/thread.jsp?thread_id=17982&article_count=26#74617

BasicPortal uses custom DAOs, Liferay uses EJBs.

Liferay also has a demo at my.liferay.com and has a ton of features (web mail, doc library, calendar, wiki, msg boards, polls, shopping, etc). Both are based on Struts.

Pros of DAOs: Light weight, very fast, simple.

Cons of DAOs: Clustering...

Pros of EJBs: Transactions, simple. You can cluster in 3 tiers, a cluster of web servers can hit a cluster of ejb servers that hit a cluster of dbs.

Cons of EJBs: Slow... like using a tank to swat a fly.