Hi Nicholas,
Thanks very much for the patch! I've created a tracker issue to track it.
https://sourceforge.net/tracker/?func=detail&aid=3361939&group_id=38899&atid=423835
One thought I had, I wonder if this could be solved in a slightly simpler
way using a custom ModelClassFactory implementation instead of adding this
to the DefaultModelClassFactory. I.e. if a new implementation of the MCF
interface was created that only used the "specific package" methods you have
provided as the default implementation, then the parser wouldn't need to
change at all; You could just pass in the different MCF implementation to
the PipeParser.
Thoughts?
Cheers,
James
On Mon, Jul 4, 2011 at 12:15 PM, Bryan Tripp <[email protected]> wrote:
> Hi Nicolas,
>
> Thanks very much for offering the patch. I see you have contacted
> James as well. He is in charge of the project and is the right person
> to follow up with.
>
> I should probably take my ID off the administrators' list, as I
> haven't been involved in the project for several years.
>
> All the best,
> Bryan
>
> On Mon, Jul 4, 2011 at 7:51 AM, Nicolas Lefebvre
> <[email protected]> wrote:
> > Hi Brian,
> >
> > I have some questions about the Hapi Validator Service. As it is written
> in
> > the Hapi documentation (http://hl7api.sourceforge.net/conformance.htmlin
> > the Message Validator section of that page), before the call to the
> > DefaultValidation.validate(Message msg, Profile profile) method, one
> needs
> > to parse the message (msg) with, for example the PipeParser.
> >
> > We have a problem when we try to parse an HL7 message for which the
> > structure is different from the message structure pre-loaded with Hapi.
> This
> > is typically the case for messages that contains segment with a data type
> > "varies". A good example concerns the case of the message QBP_Q11.
> Within
> > IHE we have specified the content of the "varies" part of that message
> > structure.
> > We have generated the class corresponding to the IHE definition of the
> > QBP_Q11 message using the Conformance Class Generator V2 (as specified in
> > the page mentioned above). When we tried to use that class for the
> > validation of QBP_Q11 messages, we do not know how to specify which of
> the 2
> > QBP_Q11 class to use.
> > In order to resolve this problem, I have created my own parser,
> that parses
> > HL7 messages specifying the package name of the conformance class to be
> used
> > for the parsing.
> > I tested this patch and using it we are now able to validate messages
> that
> > are redefined by a project (IHE or others).
> > I'd like to contribute this back to the Hapi project, so that others
> could
> > benefit from it. It indeed will allow users of hapi to parse messages
> that
> > are redefined or different from the structure defined in hapi.
> > Please let me know how to best contribute. Here is the patch. If you need
> > anything else, please do not hesitate to contact me.
> > Best regards
> > Nicolas
> >
> >
> > To specify the package name, some changes have been done in the Hapi Base
> > Library (for the Hapi.1.2-beta1 version) in the "ca.uhn.hl7v2.parser"
> > package :
> >
> > - Add 2 new methods in the DefaultModelClassFactory.java :
> >
> > public Class<? extends Message> getMessageClassInASpecificPackage(String
> > theName, String theVersion, boolean isExplicit, String packageName)
> throws
> > HL7Exception {
> > Class<? extends Message> mc = null;
> > if (!isExplicit) {
> > theName = Parser.getMessageStructureForEvent(theName,
> > theVersion);
> > }
> > mc = (Class<? extends Message>)
> findClassInASpecificPackage(theName,
> > theVersion, "message", packageName);
> > if (mc == null)
> > mc = GenericMessage.getGenericMessageClass(theVersion);
> > return mc;
> > }
> >
> >
> > private static Class<?> findClassInASpecificPackage(String name, String
> > version, String type, String packageName) throws HL7Exception {
> >
> > if (packageName == null || packageName.isEmpty())
> > return findClass(name, version, type);
> >
> > Class<?> compClass = null;
> > String classNameToTry = packageName + "." + name;
> >
> > try {
> > compClass = Class.forName(classNameToTry);
> > } catch (ClassNotFoundException e) {
> > // TODO Auto-generated catch block
> > e.printStackTrace();
> > return findClass(name, version, type);
> > }
> >
> > return compClass;
> > }
> >
> >
> >
> > - Add 3 new methods in the Parser.java :
> >
> > public Message parseForSpecificPackage(String message, String
> packageName)
> > throws HL7Exception, EncodingNotSupportedException {
> > String encoding = getEncoding(message);
> > if (!supportsEncoding(encoding)) {
> > throw new EncodingNotSupportedException(
> > "Can't parse message beginning " +
> message.substring(0,
> > Math.min(message.length(), 50)));
> > }
> >
> > String version = getVersion(message);
> > if (!validVersion(version)) {
> > throw new HL7Exception("Can't process message of version '" +
> > version + "' - version not recognized",
> > HL7Exception.UNSUPPORTED_VERSION_ID);
> > }
> >
> > myValidator.validate(message, encoding.equals("XML"), version);
> >
> > Message result = doParseForSpecificPackage(message, version,
> > packageName);
> >
> > myValidator.validate(result);
> >
> > result.setParser(this);
> >
> > return result;
> > }
> >
> >
> > public Message doParseForSpecificPackage(String message, String version,
> > String packageName) throws HL7Exception, EncodingNotSupportedException {
> >
> > Message m = null;
> > return m;
> > }
> >
> >
> > protected Message instantiateMessageInASpecificPackage(String theName,
> > String theVersion, boolean isExplicit, String packageName) throws
> > HL7Exception {
> > Message result = null;
> >
> > try {
> > DefaultModelClassFactory localIHEFactory = new
> > DefaultModelClassFactory();
> > Class messageClass = localIHEFactory
> > .getMessageClassInASpecificPackage(theName, theVersion, isExplicit,
> > packageName);
> > if (messageClass == null)
> > throw new ClassNotFoundException("Can't find message
> class
> > in current package list: "
> > + theName);
> > log.info("Instantiating msg of class " +
> > messageClass.getName());
> > Constructor constructor = messageClass.getConstructor(new
> > Class[]{ModelClassFactory.class});
> > result = (Message) constructor.newInstance(new
> > Object[]{myFactory});
> > } catch (Exception e) {
> > throw new HL7Exception("Couldn't create Message object of
> type "
> > + theName,
> > HL7Exception.UNSUPPORTED_MESSAGE_TYPE, e);
> > }
> >
> > result.setValidationContext(myContext);
> >
> > return result;
> > }
> >
> >
> > - Add 1 new method in the PipeParser.java :
> >
> >
> > @Override
> > public Message doParseForSpecificPackage(String message, String
> version,
> > String packageName) throws HL7Exception, EncodingNotSupportedException {
> >
> > // try to instantiate a message object of the right class
> > MessageStructure structure = getStructure(message);
> > Message m =
> > instantiateMessageInASpecificPackage(structure.messageStructure, version,
> > structure.explicitlyDefined, packageName);
> >
> > parse(m, message);
> >
> > return m;
> > }
> >
> >
> >
> >
> >
> > Nicolas Lefebvre
> >
> > Engineer in the IHE-Development Project
> >
> > INRIA Rennes
> > Campus Universitaire de Beaulieu
> > F-35042 Rennes Cedex FRANCE
> >
> > Cell : (+33)6 72 05 40 18
> >
> > Phone : (+33)2 99 84 74 56 / Fax: (+33)2 99 84 71 71
> > Mail : [email protected]
> >
> >
> >
> >
>
>
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threats, fraudulent activity, and more. Splunk takes this data and makes
sense of it. IT sense. And common sense.
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