A Comprehensive Guide to IBM WebSphere Host Publisher Version 3.5

544 IBM WebSphere Host Publisher Version 3.5

Figure 17-40 HelloEJB Input

Once the EJB Access Bean is instantiated, it communicates with the Host

Publisher EJB, which is located by using the JNDI properties for this EJB Access

Bean. The communication is via RMI/IIOP. The response from CICS is illustrated

in Figure 17-41.

Figure 17-41 HelloEJB output

17.4.6 Scenario 6: Host Publisher EJB access with chaining

The EJB support implementation in Host Publisher supports Integration Object

chaining. This scenario shows how to access the EJB Access Bean when using

Integration Object chaining. For information about Integration Object chaining,

see Chapter 12, “Integration Object chaining” on page 345.

Chapter 17. EJB application support 545

In order to support chained Integration Objects, the Host Publisher EJB is

implemented as a stateful session bean, where the life cycle of a Host Publisher

EJB instance corresponds to the processing of an Integration Object chain.

When EJB Access Beans for an Integration Object chain are processed, two EJB

Access Bean properties are used:

򐂰 hPubAccessHandle

Contains the handle for the Host Publisher EJB instance corresponding to the

Integration Object chain.

򐂰 hPubLinkKey

Contains the key that represents the connection for the Integration Object

chain.

EJB Access Bean chaining in a Web container

When EJB Access Beans are processed in a Web container, the EJB Access

Bean saves the values of the hPubAccessHandle and hPubLinkKey properties in

the HttpSessionObject associated with the client session. The properties are

retrieved by subsequent EJB Access Beans in processing the Integration Object

chain.

The EJB Access Bean for the first Integration Object in a chain creates an

instance of the Host Publisher EJB. That instance is used for all EJB Access

Beans for the subsequent Integration Objects in the chain. After the processing

of the EJB Access Bean for the last Integration Object in a chain, the Host

Publisher EJB instance corresponding to that Integration Object chain is

removed.

EJB Access Bean chaining outside of a Web container

When EJB Access Beans are processed outside of a Web container (for

example, directly from a Java program), the calling program must retrieve the

values of the hPubAccessHandle and hPubLinkKey properties. The properties

can be retrieved after the EJB Access Bean for the first Integration Object in the

chain has been processed. The calling program must set the two properties for

all subsequent EJB Access Beans in the Integration Object chain before they are

processed.

The procedure to create the Integration Objects is exactly the same. However,

you need to always remember to activate the Create EJB Integration Object

Support option, as illustrated in Figure 17-3 on page 510.