How can we ensure that there is a single instance of a class in a clustered environment

Question

How can we ensure that there is a single instance of a class in a clustered environment? The class is Serializable.

Answer 1

You need to correctly implement readResolve method of your singleton class.

Preferably, I think terracotta would help.

This link has more help http://forums.terracotta.org/forums/posts/list/771.page

Answer 2

Use a container that provides application scoped singletons, e.g. Seam, Spring etc.

Answer 3

1. Use container which provides you with this facility.
2. If use of container is not a feasible option, then create a RemoteFactory which will provide you with instance of the class in context.