Application Services Jobs › Session Bean Jobs

Session Bean Jobs

A session bean represents business logic or action to be taken (for example, charging a credit card or adding items to an online shopping cart).

Unlike entity beans, which are stored in a database, session beans may be destroyed after each use. For example, when a session bean is invoked to perform credit card validation, the application server creates an instance of that session bean, performs the business logic to validate the credit card transaction, and then destroys the session bean instance after the credit card transaction has been validated.

You can use a session bean under the following conditions:

• The bean represents a procedure and not a business entity. For example, you use a session bean to encrypt data or add items to an online shopping cart.
• The state of the bean does not have to be kept in permanent storage. For example, when the bean instance terminates or the application server shuts down, the bean's state is no longer required.

The following diagram shows the functional relationship between the scheduling manager, CA WA Agent for Application Services, and a session bean residing on an application server:

The Session Bean job lets you access a session bean on an application server. This job type can make a Remote Procedure Call (RPC) to the session bean, invoke a method that defines the business logic, pass parameters to the method, and have the results returned as serialized Java output. The output can be stored on the agent computer as text in the spool file or as a serialized Java object in the spool directory or a destination file you specify.

Note: To run these jobs, your system requires CA WA Agent for UNIX, Linux, or Windows and CA WA Agent for Application Services.

You can access stateless and stateful session beans using the Session Bean job. The job acts in a similar way for both types of beans. For both stateful and stateless beans, you can specify parameters to pass to the method. When you define a stateful session bean, however, you must specify parameters to define the bean. After the method is invoked, the agent destroys the stateful bean.

Use a stateless Session Bean job to invoke a single instance of a method on the bean, such as encrypting data or sending an email to confirm an order. Use a stateful Session Bean job to invoke the same method on the bean multiple times, such as adding multiple items to an online shopping cart.

A Session Bean job requires a dedicated connection between the agent and the application server. To define a Session Bean job, you require the following information:

• Initial context factory supplied by the Java Naming and Directory Interface (JNDI) service provider
• Service provider URL for accessing the JNDI services
• Session bean JNDI name
• Method to be invoked