Issue while retrieving data from BAPI

Question

Problem:
The initial exception that caused the request to fail, was:
com.sap.dictionary.runtime.DdException: Wrong amount type (not decimal): Unit service cannot be instantiated
at com.sap.dictionary.runtime.DdBroker.getUnitService(DdBroker.java:215)
at com.sap.dictionary.runtime.DdBroker.getUnitService(DdBroker.java:233)
at com.sap.tc.webdynpro.services.datatypes.core.DataTypeBroker.getUnitService(DataTypeBroker.java:337)
at com.sap.tc.webdynpro.progmodel.context.DataAttributeInfo.initReferenceAttribute(DataAttributeInfo.java:342)
at com.sap.tc.webdynpro.progmodel.context.NodeInfo.initStructureType(NodeInfo.java:708)
... 30 more
I have a BAPI  - ZPM_CREATE_ORDER. I am trying to write a record to that BAPI. Did the Model Import from R/3[including the Commit ].
The structures of BAPI are like this:
Zpm_create_Order_Input
        Order         -  Zpm_Hdr
     Operations    -  [ Line Items structure ]
I have created the mapping between Model & Custom Controller with Order & Operations. Did the mapping between the Custom Controller & the View Controller. Binded them to the UI elements from View Controller with an input form.
But there are ABAP - decimal fields under Operations -  price & Amount  which are a Currency field and Quantity . So when I just try to run the application, I get the amount mismatch error. When I say run, I could n’t even see the GUI even. I get the 500 error with the above problem.
I read in the forums that I need to declare as a Simple type and re cast the fields to right type and bind that structure back. How ever, I could n’t get the complete understanding of it.
For a Retrieval Bapi with the exact same structure, the same issue if I map the Operations. How ever, if I skip the Operations and just map the Order i.e., header, then I could retrieve the records.
Interestingly even if I just map a String(char) field under Operations structure I am getting teh same error.
Any help is appreciated. Thanks in advance...

Answer 1

Satyajit,
You are right. One of the fields needed is Waers(currency) which I have mapped from the Model to Custom Controller. I think, that is one of the causes but there are other fields too (for instance, Decimal type).
The surprising thing to me is that, even if I just map the character fields in that structure and not map the Decimal or Currency fields, then also I am getting the same error.
Thanks for the Reply...
--Vivek