EJB and Singleton

[chao cai]

Can we call a Singleton instance in the EJB method, also the singleton instance is synchronized?

[Paul Sturrock]

Yes you can, so long as the singleton is read only, i.e. it provides a cache of static data for your ejbs.
[ August 23, 2006: Message edited by: Paul Sturrock ]

[chao cai]

But I wanna use it as the read/write cache,so the singleton instance will synchronize the get/set method.
Can we do it?

[Paul Sturrock]

No.

You can use an RMI service to create a read/write cache for EJBs (it has to be a service to allow it to be clusterable). Not simple. See here for a discussion.

The other approach is to consider if you can live without the cache. Using a read only data base table, rather than cache might be tolerable performance wise, and is a great deal easier.

[chao cai]

The clustable is not the matter to me,so can I use the singleton as the cache,if not why?

[Jeroen T Wenting]

never say it's not an issue.