This new kind of bean helps developers create components that implement the pattern that gives its name—no need to declare class methods and attributes to create them anymore.
Its behavior is a crossover between stateless and stateful beans, as it holds its state between calls but isn't expected to keep the state consistent in case of a server shutdown. As just one instance of such a bean is available at any given time, the client state must not be kept by it for obvious reasons.
The application container guarantees that one bean instance is loaded per JVM. This means that each Managed Server—an instance of WebLogic Server—will load and keep only one instance of the class in memory. If your WebLogic domain has just one instance, the bean is truly singleton in the sense that only one instance will receive every single request. But, the most common scenario is to have a cluster of managed servers so you end up with several instances in memory, each receiving the requests...