Patterns: Implementing Self-Service in an SOA Environment

Chapter 12. J2EE Connector Architecture scenario 391

The ESB is implemented using the service integration bus. The bus acts as

an intermediary for the Web service. Using an ESB insulates the application

from changes in the Web service location and provides the opportunity to

implement mediations or security measures in the future.

򐂰 JCA Module

This component sends the requests to create, update, or delete customer

data to the CICS application.

򐂰 Resource Adapter

The CICS ECI resource adapter is used to access the back-end CICS

transaction.

򐂰 CRM

A CICS transaction that manages the customer database.

This scenario illustrates the following application pattern using messaging

technology:

򐂰 Directly Integrated Single Channel application pattern:

ITSOMart sends the customer information directly to the back-end

application. The connection to the CICS system is done using a J2C Java

bean that has been deployed as a Web service.

12.2 System design overview

In this scenario (Figure 12-2 on page 392) we connect the ITSOMart application

to a back-end CICS application called MartAcct.ccp using the CICS ECI resource

adapter. The ECI resource adapter is one of the resource adapters that allows

Java applications to connect to CICS. It uses the External Call Interface (ECI) of

the CICS Transaction Gateway (CICS TG) to communicate with CICS. CICS TG

can link to a CICS enterprise-tier, or back-end application passing data in a

buffer called the COMMAREA. The CICS application receives customer info

through the COMMAREA from the ITSOMart application.