Developing an enterprise bean or J2EE client to manage ActivitySessions

Use this task to write the code needed by a session EJB or J2EE client application to manage an ActivitySession, based on the example code extract provided.

In most situations, an enterprise bean can depend on the EJB container to manage ActivitySessions within the bean. In these situations, all you need to do is set the appropriate ActivitySession attributes in the EJB module deployment descriptor, as described in Configuring EJB module ActivitySession deployment attributes. Further, in general, it is practical to design your enterprise beans so that all ActivitySession management is handled at the enterprise bean level.

However, in some cases you may need to have a session bean or J2EE client participate directly in ActivitySessions. You then need to write the code needed by the session bean or J2EE client application to manage its own ActivitySessions.

Note: Session beans that use BMT and have an Activate at setting of Activity session can manage ActivitySessions. Entity beans cannot manage ActivitySessions; the
EJB container always manages ActivitySessions within entity beans.

When preparing to write code needed by a session bean or J2EE client application to manage ActivitySessions, consider the points described in ActivitySessions and transaction contexts.

To write the code needed by a session EJB or J2EE client application to manage an ActivitySession, complete the following steps based on the example code extract below:

1. Get an initial context for the ActivitySession.

2. Get an implementation of the UserActivitySession interface, by a JNDI lookup of the URL java:comp/websphere/UserActivitySession . The UserActivitySession interface is used to begin and end ActivitySessions and to query various attributes of the active ActivitySession associated with the thread.

3. Set the timeout, in seconds, after which any subsequently started ActivitySessions are automatically completed by the ActivitySession service. If the session bean or J2EE client does not specifically set this value, the default timeout (300 seconds) is used.

   The default timeout can also be overridden for each application server, on the server-> Activity Session Service panel of the administrative console.

4. Start the ActivitySession, by calling the beginSession() method of the UserActivitySession.

5. Within the ActivitySession, call business methods to do the work needed. You can also call other methods of UserActivitySession to manage the ActivitySession; for example, to get the status of the ActivitySession or to checkpoint all the ActivitySession resources involved in the ActivitySession.

6. End the ActivitySession, by calling the endSession() method of the UserActivitySession.

Example

The following code extract provides a basic example of using the UserActivitySession interface:

// Get initial context   InitialContext ic = new InitialContext();
// Lookup UserActivitySession   UserActivitySession uas = (UserActivitySession)ic.lookup("java:comp/websphere/UserActivitySession");

// Set the ActivitySession timeout to 60 seconds   uas.setSessionTimeout(60);
// Start a new ActivitySession context   uas.beginSession();
// Do some work under this context   MyBeanA beanA.doSomething();
  ...
  MyBeanB beanB.doSomethingElse();
// End the context   uas.endSession(EndModeCheckpoint);

Related concepts
The ActivitySession service