Synchronous Messages

Synchronous messages have the quality of service Best Effort. On the one hand, the application must ensure that there are no duplicate messages or data losses. On the other hand, the application receives error messages. Best Effort also means that no transactional concepts are involved.

• If an adapter receives a synchronous XI message, it must either send a synchronous response message or, if an error has occurred, an application error. In the event of a technical error, the adapter can also send an exception. The Adapter Framework messaging service converts the exception to a SystemError message and sends it to the Integration Server.
  Note

  Synchronous response message: Open CCIInteraction..java and search for the character string CS_SYNCRESP.

  Application error: Open CCIInteraction.java and search for the character string CS_SYNCAPPERR.

• If an adapter forwards a synchronous message to the Adapter Framework messaging service, the response message is sent back to the adapter along the same path, but in the opposite direction.

• If you are using the default module ModuleProcessorExitBean to call the JCA adapter, the module uses XIInteractionSpec to specify the synchronous message transfer. In this case, set the function name for XIInteractionSpec to XIInteractionSpec.CALL.

  If the adapter receives such an XIInteractionSpec, it must return an instantiated and filled XIMessageRecord (in the case of a successful response message or an application error) in the XIInteractionSpec.execute() call or, if an error occurs, XIAdapterException.

• If you are not using the default module ModuleProcessorExitBean, you can define your own communication models for the adapter implementation to replace the CCI InteractionSpec.

  Your last module must return a response message to the module processor to be called.

• The following methods are available to enable you to read error information in the form of an ErrorInfo object from the message, or to set the error information in a message.
  • Message.getErrorInfo()
  • Message.setErrorInfo()

  You can read or set the following ErrorInfo attributes:

  Name	Description
  ErrorCode	Application error code
  ErrorArea	Contains the adapter namespace and the adapter type
  ErrorCategory	Must be set to Application
  AdditionalErrorText	Text for the application error
  ApplicationFaultInterface	Specifies in the Enterprise Services Repository the interface that processes the application error messages
  ApplicationFaultInterfaceNamespace	Namespace of the interface

  The following methods are available for reading and setting the attributes:

  • ErrorInfo.setAttribute()
  • ErrorInfo.getAttribute()
  • ErrorInfo.getSupportedAttributeNames()

…

try {

myRespMsg = myAdapter.call(myReqMsg);

if (myRespMsg != null) //synchronous

moduleData.setPrincipalData((Object) myRespMsg.getXIMessage());

else // asynchronous

moduleData.setPrincipalData(null);

…

catch(Exception e) {

{

TRACE.catching(SIGNATURE, e);

ModuleException me = new ModuleException("Temporary error: Adapter call failed. Reason: " + e.getMessage(), e);

TRACE.throwing(SIGNATURE, me);

throw me;

}

…