When to use Session Beans?

5 March 2012 By Nithya Vasudevan 2,081 views No Comment
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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.

A session bean must be annotated or denoted in the deployment descriptor as a stateless or stateful or singleton session bean. These annotations are component-defining annotations and are applied to the bean class.

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