Managing Information Access to an Enterprise Information System Using J2EE and Services Oriented Architecture

Chapter 5. Using J2EE Connector Architecture 97

The client uses an interaction to execute functions on the EIS. The interaction

modes involves how the request is handled by the resource adapter and is

specified on the InteractionSpec by stating one of the following:

򐂰 SYNC_SEND

The execution only sends an input to the EIS via the resource adapter. No

output is expected.

򐂰 SYNC_RECEIVE

The execution receives a synchronous output record from the EIS.

򐂰 SYNC_SEND_RECEIVE

The execution sends an input to the EIS, and a synchronous output record is

expected.

The EIS can also make calls into the application component using Enterprise

JavaBeans (EJB) that are deployed on the application server. Inbound

communication is only available when the adapter is running in a J2EE

application server.

5.2 EIS integration using J2C

This section describes how to use a J2C resource adapter in various integration

schemes. EIS-based integration typically involves a J2C resource adapter that is

running in managed mode to take advantage of the application servers quality of

service functionality.

As mentioned earlier, a resource adapter can expose its outbound functionality

through CCI. This functionality can directly interact with the EIS. The EIS

connectivity framework provides a facade into the EIS via the resource adapter,

which provides de-coupling between the service provided by the J2C resource

adapter and application services.

The JCA 1.5 specification stipulates how inbound communication can be

accomplished using EJB. EJB enables the EIS to make calls to the application

component when events occur in the EIS system.

5.2.1 J2C outbound integration pattern

The outbound integration pattern involves an application component that is

running on an application server or stand-alone Java application, which executes

requests on the J2C resource adapter that interacts with the EIS.

98 Managing Information Access to an EIS Using J2EE and Services Oriented Architecture

There are two basic patterns when running on an application server, one involves

straight calls and the other involves exposing the resource adapter as a service.

Common Client Interface invocation

The patterns when interacting from within an application server use an EJB to

make calls on the resource adapter through CCI calls. The EJB can then be

exposed as an Enterprise Application Integration framework within the managed

application space, or it can used directly. Developing a framework gains flexibility

and potentially eases integration with other parts of the application.

Example 5-1 is shows the sample code which makes a call on a resource

adapter.

Example 5-1 Sample CCI call to an EIS

ConnectionFactory cicsFactory =ServiceLocator.getConnectionFactory(“eis/CICS”);

Connection conn = cicsFactory.getConnection();

InteractionSpec spec = new ECIInteractionSpec();

spec.setCommareaLength(commAreaLength);

spec.setTPName(“TRDR”);

spec.setFunctionName(“TRADERBL”);

Interaction interaction = conn.createInteraction(spec);

interaction.execute(spec,requestRecord, responseRecord);

Enterprise Application Integration framework

The Enterprise Application Integration (EAI) framework is the implementation of

a system process of the EIS component model that is described in the following

sections:

򐂰 2.2.2, “Architecture options” on page 30

򐂰 2.2.5, “Conceptual architecture” on page 37

򐂰 7 2.2.6, “Logical architecture” on page 47

The EIS system process uses a session bean implementation. The EIS features

are a Java implementation of existing functions in the EIS.

The EAI framework interacts with the EIS through the resource adapter and is

exposed as features that the session bean uses. This interaction creates

flexibility and de-coupling of the EIS features that are used when integrating. It

allows for the quick reuse of existing features (for example, GetCompanyList that

is used to retrieve a list of companies in the system). The EAI framework gives

developers an clearly defined infrastructure on how they should add new

features and extend the EIS access.