Without going deep in details, the field (an hashmap) of the stateless ejb contains data fetched from rss, forecasts and other data taken from internet that are loaded once a day.
Clients can't connect directly to internet, and this kind of data is not storable into the application database.
Loading and collecting information from these sources would be very intensive if we didn't cache in some way; that's the reason for this cache.
Thanks
Ale