Use this task to configure Enterprise JavaBeans (EJB) 3.1 session bean methods to run asynchronously. You can make some or all of your bean methods asynchronous.
Create a bean implementation class for a singleton session bean, introduced by the Enterprise JavaBeans (EJB) 3.1 specification. The EJB container initializes only one instance of a singleton session bean, and that instance is shared by all clients. Because a single instance is shared by all clients, singleton session beans have special life cycle and concurrency semantics.