We need to create singleton classes to cache database data. Using an EJB container we are not guaranteed that truly one object is being instantiated and shared. I have heard various answers to this, including some mysterious "well, it depends on the classloader..." answers. From what I have found online, the answer appears to have something to do with declaring the class final, or using @service, but I don't know if these are definitely the solution. How can we make a singleton that is definitely really a singleton? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4105694#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...