You can connect to CICS® in a number of ways. This section shows some of the options.
If you use the CICS Transaction Gateway, you can
connect to CICS using the IBM® CICS ECI
Resource Adapter, which is a JCA adapter. The CICS ECI Resource Adapter is shipped with WebSphere® Integration Developer
and the CICS Transaction Gateway. For more information on integrating CICS using the CICS ECI
Resource Adapter, see: .
When you use the CICS ECI Resource Adapter, CICS programs can act as service providers (they cannot act as service requesters).
The WebSphere Integration Developer external
service wizard works with the CICS ECI
Resource Adapter to create services that call programs on a CICS server. You use the external
service wizard to create a CICS import:
the wizard helps you to configure the adapter; and also to develop
and generate a service. The CICS import
is an import with an enterprise information system (EIS) binding that
connects to the CICS ECI Resource
Adapter, which in turn connects to the CICS Transaction
Gateway. For more information on how to create
the CICS import see: .
CICS provides a Web service interface that allows you to integrate CICS programs using Web services. Because WebSphere ESB and WebSphere Process Server provide support for Web services, you can connect to CICS using the CICS Web service interface. At run time, WebSphere ESB or WebSphere Process Server, mediates between the Web service interface provided by CICS, and the interface expected by the service requester or service provider.
The CICS Web service interface is bidirectional; therefore, CICS applications can act as service requestors or service providers. If a CICS program needs to act as a service requester, you must create a Web services export to connect to the CICS Web service; if a CICS program needs to act as a service provider, you must create a Web services import to connect to the CICS Web service.
This scenario involves working with the CICS Web service support; therefore, it requires some knowledge in this area. For more information on implementing CICS Web services, see: Application Development for CICS Web Services.
WebSphere MQ for z/OS® has an MQ-CICS bridge, so you can communicate with CICS through WebSphere MQ. WebSphere Enterprise Service Bus and WebSphere Process Server provide MQ bindings on imports and exports, and you can use MQ bindings to communicate either with WebSphere MQ or with the WebSphere MQ-CICS bridge.
If you want to use the MQ-CICS bridge you need to create data bindings for the MQ body and header: the data bindings must construct MQ messages in the correct format for the bridge.
You can set, clear, or retrieve some information carried in the MQ message header structures defined by the MQ CICS Bridge. For example, you can set values in the MQCIH header, then send the MQ message to a CICS application, through the MQ CICS Bridge. In WebSphere Enterprise Service Bus, MQCIH header values can be set dynamically using meditation primitives, or statically by setting MQImport binding properties. In WebSphere Process Server, MQCIH header values can be set statically in a business module by setting MQImport binding properties.
From your WebSphere Enterprise Service Bus or WebSphere Process Server application, you can create a call to a CICS service, through the MQ CICS bridge. Your application can handle the response from the CICS service. The response could be a fault message. To handle the response, use WebSphere Integration Developer to add an MQ Import connecting to the WebSphere MQ queue supported by the MQ CICS Bridge. You then configure your application to add the required MQCIH header to the message. When your application runs, an MQ request message is sent to the CICS service through the MQ CICS Bridge. The CICS service returns a response to your application through the MQ CICS Bridge. The MQ headers in the response will include MQCIH headers. The response could be a fault message, and must be handled.
A WebSphere Enterprise Service Bus application can mediate a request from an MQ Client, where the request already has an MQCIH header. This request can be forwarded on to a CICS service, through the MQ CICS Bridge. The WebSphere Enterprise Service Bus application can add, modify, or remove the MQCIH header, and returns the CICS response to the client. The response could be a CICS fault, and must be handled correctly.
A WebSphere Enterprise Service Bus application can mediate a request from an MQ Client, where the request already has an MQCIH header, and is received from the MQ CICS Bridge. The WebSphere Enterprise Service Bus application can add, modify, or remove the MQCIH header, and then forward the request to a non-CICS service. The service response is returned to the client.
Diagram from Use case could appear here.