When to Use Session Beans

Stateful session beans are appropriate if any of the following conditions are true:

• The bean’s state represents the interaction between the bean and a specific client.

• The bean needs to hold information about the client across method invocations.

• The bean mediates between the client and the other components of the application, presenting a simplified view to the client.

• Behind the scenes, the bean manages the work flow of several enterprise beans.

To improve performance, you might choose a stateless session bean if it has any of these traits:

• The bean’s state has no data for a specific client.

• In a single method invocation, the bean performs a generic task for all clients. For example, you might use a stateless session bean to send an email that confirms an online order.

• The bean implements a web service.

Singleton session beans are appropriate in the following circumstances:

• State needs to be shared across the application.

• A single enterprise bean needs to be accessed by multiple threads concurrently.

• The application needs an enterprise bean to perform tasks upon application startup and shutdown.

• The bean implements a web service.