Tag Archives: OTD Importer

Java CAPS Quick Note 002 – JCA Transform HL7 Delimited to Custom XML

This Quick Note discusses a solution to the use case provided by Marcus Davies.

I am trying to read HL7 from JMS (preferably stcms) and populate an outbound XML data structure (different to the XML generated by the decoder).
I have been thinking of doing one of the following […]:
1.    Use a Concrete JMS WS using the HL7 encoders to unmarshal the HL7 and use JAXB to populate the outbound XML.  Unfortunately this does not appear to connect to the stcms queue as I can not see any receivers
2.    Use a JCA MDB to read from the stcms JMS queue – this works but I don’t think I can use the HL7 encoder like this
3.    Use and MDB to read from JMS, manually unmarshal the HL7 and use JAXB to populate the data structure
Ideally I would like to use the HL7 encoders.  Do you think the first approach should work?

Number 1 will not work as at end of February 2009 because the JMS BC does not properly decode the HL7 delimited message. This is a know issue. I don’t know what the status of this is. The only BCs that know how to deal with HL7 delimited, that I know of, are the File BC and the HL7 BC.

Number 2 should work. I did not personally try it. You can invoke an encoder library from Java. Have a look at http://wiki.open-esb.java.net/Wiki.jsp?page=UseEncodersInJavaSE.

Number 3 should work but it will be very laborious.

I have a Number 4, which uses a HL7 OTD and a custom XSD-based OTD in a JCA EJB. You may or may not like it but it’s the best thing to do if you can not use BPEL 2.0 to do the mapping and you don’t want to build a repository-based solution (which would be the best for your case anyway).

The solution involves the use of:
1.    HL7 2.3.1 OTD Library (Java CAPS 6 Repository)
2.    JMS JCA to trigger a MDB with a HL7 Delimited message
3.    JMS JCA to write result message out
4.    JCA MDB to do the processing
5.    OTDImporter to provide HL7 2.3.1 OTD and custom XSD-based OTD to the EJB for “convenient” mapping

Brief steps to implement this solution are given in Quick Note 002 at QuickNote002_For_Marcus_Davies.pdf. Archive containing project exports and sample data is provided at QuickNote002.zip. The code will work in Java CAPS 6 Update 1.