Which CMS are you using in Java and what is your experience with it (in terms of extensibility, usage comfort, framework API, memory usage, performance etc.). I am looking for suggestions.
Specifically any one that supports a search engine(probably lucene or similar).
We are using opencms. I haven't tried to extend it beyond changing page templates (writing JSPs) but where usage is concerned it gets the job done, albeit the feeling you get is that you fight the system all the way through.
Memory consumption on the JVM running opencms is right now 161 Mb, the JVM running since January 2008. This is on a low traffic site serving around 6000 hits per month with an average traffic of 1800 Mb per month.
It very much depends on your requirements. For instance, Apache Lenya is very complete, but that also makes it large and more complicated. If you don't require most of their functionality, you may be better of with a smaller cms.
the part "what do you use" is easy to answer, but as "Confusion" already said - the rest depends upon your needs:
We're starting to use liferay, which is basically a portal server coming with cms portlets. In terms of
extensibility: It uses the portlet api
usage comfort: Well... it didn't hinder us using it.
framework API: Having the portlet api as the api, this was more appealing than (e.g.) OpenCMS which has its own API.
memory usage: No hard knowledge yet, but for our needs we don't expect bad things from any cms available.
performance: Same as Memory.
If you want to know, what you should use, please ask more specific questions. If you are interested in a list of systems, please refer to http://en.wikipedia.org/wiki/List_of_Content_Management_Systems or http://en.wikipedia.org/wiki/Content_management_framework and filter out the java ones.
I used Magnolia and found it very clean and customizable.
