SessionBean in JavaEE 6 Tutorail

A stateless session bean does not maintain a conversational state with the client. When a client

invokes the methods of a stateless bean, the bean’s instance variables may contain a state specific to

that client but only for the duration of the invocation. When the method is finished, the client-specific

state should not be retained. Clients may, however, change the state of instance variables in pooled

stateless beans,and this state is held over to the next invocation of the pooled stateless bean . Except

 

during method invocation, all instances of a stateless bean are equivalent, allowing the EJB container

 

to assign an instance to any client. That is, the state of a stateless session bean should apply across

 

all clients.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 fewer stateless

 

session beans than stateful session beans to support the same number of clients.

 

A stateless session bean can implement a web service, but a stateful session bean cannot.