An EIS export is a Service Component Architecture (SCA) export, it allows services to be available to clients outside the SCA module. An EIS export, is used to transfer data from an external EIS into the SCA module. An EIS export can be thought of as a subscription service listening to an external request from an EIS. The SCA component that utilizes the EIS export views it as a local service.
The role of the EIS export is to bridge the gap between SCA components and external EISs. External services can be treated as an EIS export. In this case, the external service sends its data in the form of periodic notifications.
The EIS export provides SCA components with a uniform view of the services external to the module. This allows components to communicate with the variety of external EISs like SAP, Siebel or PeopleSoft, using a consistent SCA model.
The export features a listener implementation receiving requests from the EIS. The listener implements either javax.jms.MessageLister interface for the JMS Export or a Resource Adapter specific listener interface. The export also contains a component implementing interface, exposed to the EIS through the export.
The runtime implementation of an EIS export connects the listener with the component implementing interface. The export maps the EIS request to the invocation of the appropriate operation on the component. Bindings are created at three levels: a Listener Binding, which uses contained Native Method Binding, which in turn uses Data Binding.
The Listener Binding relates the listener receiving requests with the component exposed through the Export. The export definition contains the name of the component; the runtime locates it and forwards requests to it.
The Native Method Binding associates the native method or the event type received by the listener to the operation implemented by the component exposed via the export. There is no relation between the method invoked on the listener and the event type, all the events arrive through one or more methods of the listener. The Native Method Binding uses the function selector defined in the export to extract the native method name from the inbound data and Data Bindings to bind the data format of the EIS to a format understood by the component.
The runtime scenario for an EIS export is as follows. The EIS request triggers invocation of the method on the listener implementation. The listener locates and invokes the Export Handler passing to it all the invocation arguments (for example a JMS Message for a JMS Export). The handler creates the Listener Binding Implementation. Then, the handler instantiates the function selector and sets it on the Listener Binding. In the next step, the export handler initializes Native Method Bindings and adds them to the Listener Binding. For each Native Method Binding, the Data Bindings are also initialized. Finally, the handler invokes the Listener Binding. The Listener Binding locates exported components, and uses the Function Selector to retrieve the native method name. This name is used to locate Native Method Binding which then invokes the target component.
Last updated: Wed 06 Dec 2006 07:08:08
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