SessionBean in JavaEE 6 Tutorail
A stateless session bean does not maintain a conversational state with the client. When aclient
invokes the methods of a stateless bean, the bean’s instance variables maycontain a state specific to
that client but only for the duration ofthe invocation. When the method is finished, the client-specific
state should not beretained. Clients may, however, change the state of instance variables in pooled
stateless beans,and this state is held over to the next invocation of thepooled stateless bean. Except
during method invocation, all instances of a stateless beanare equivalent, allowing the EJB container
to assign an instance to any client. Thatis, the state of a stateless session bean should apply across
allclients.Because they can support multiple clients, stateless session beans can offer better scalability
for applications that require large numbers of clients. Typically, an application requires fewerstateless
session beans than stateful session beans to support the same number ofclients.
A stateless session bean can implement a web service, but a stateful sessionbean cannot.