1 Reply Latest reply on Feb 14, 2007 4:09 PM by Thomas Diesler

    Jaxb EAR project - please help

    John McClain Newbie

      I have an EAR project. In the project I have a web app and an EJB. My goal is to have a REST webservice servlet that gets the XML payload, uses JAXB to unmarshal it into XJC generated classes, then pass those classes to an EJB for processing. What I have found is the following:

      scenario 1)
      here is the EAR fle structure:
      EAR
      bpo-lib.jar - holds the XJC generated classes
      bpo-ejb.jar - references bpo-lib.jar in its manifest.mf file
      bpo-webservice.war - holds the rest servlet that does the unmarshaling and passes unmarshaled objects to EJB
      - holds bpo-lib.jar in WEB-INF/lib - I did this because I saw in the FAQ that JAXBContext.newInstance tries to load
      classes using the same clasloader that the JAXBContext class is in
      - references bpo-lib.jar in its manifest.mf file

      The result is that I can unmarshal the data into the XJC classes, but after I pass them to the EJB, I try to cast the object into the expected types and get a class cast exception. this is possibly the behavior mentioned in https://jaxb.dev.java.net/faq/#classloader


      scenario 2)
      here is the EAR file structure:
      EAR
      bpo-lib.jar - holds the XJC generated classes
      bpo-ejb.jar - references bpo-lib.jar in its manifest.mf file
      bpo-webservice.war - holds the rest servlet that does the unmarshaling and passes unmarshaled objects to EJB
      - does NOT hold bpo-lib.jar in WEB-INF/lib - I did this because in theory, on JBOSS4.0.4GA,
      the EAR classes are accessible to the WAR context. I.E., I should NOT have to put the bpo-lib.jar file
      in both the WEB-INF/lib dir and the EAR file
      - references bpo-lib.jar in its manifest.mf file


      The result is that I can NOT unmarshal the data into the XJC classes.


      To analyze this, I checked what classes the JAXBContext knows about, and what I found was that when it unmarshalled data, I had this set of classes:
      boolean
      byte
      char
      com.homeq.bpo.domain.FirstAmericanSchema.request.AppraisalStatusResponses
      com.homeq.bpo.domain.FirstAmericanSchema.request.AppraisalStatusResponses$AppraisalStatusResponse
      com.homeq.bpo.domain.FirstAmericanSchema.request.AppraisalStatusResponses$AppraisalStatusResponse$Notes
      com.homeq.bpo.domain.FirstAmericanSchema.request.NoteType
      com.homeq.bpo.domain.FirstAmericanSchema.request.ResultsDataType
      com.sun.xml.bind.api.CompositeStructure
      double
      .
      .
      .

      When it did not unmarshal data it had this set of classes:
      boolean
      byte
      char
      com.homeq.bpo.domain.FirstAmericanSchema.request.ObjectFactory
      com.sun.xml.bind.api.CompositeStructure
      double
      float
      .
      .
      .

      The above shows (I think) that I MUST have the bpo-lib.jar in the WEB-INF/lib dir as the classloader that loads JAXBContext must also load the generated files. But as shown in scenario 1 above, this prevents you from also referencing those classes in an EJB as an EJB should not access classes loaded inside of the WAR classloader.

      Would I be correct in stating that using JAXB in a rest based web service on JBOSS4.0.4GA cannot be done, or am I missing something?