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  1. Weld
  2. WELD-625

Local no-interface view EJB3.1 proxy requests superclass of EJB from container



    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Rejected
    • Affects Version/s: 1.0.1.Final
    • Fix Version/s: None
    • Component/s: None
    • Labels:
    • Environment:
    • Steps to Reproduce:

      Install Glassfish 3.0.1 or 3.1r15
      Deploy test case
      Browse to /ErrorDemo off context-root
      Click "cdi" link

      Install Glassfish 3.0.1 or 3.1r15 Deploy test case Browse to /ErrorDemo off context-root Click "cdi" link
    • Workaround:
      Workaround Exists
    • Workaround Description:

      Use EJBs with local interface views

      Use EJBs with local interface views


      If Weld (CDI) is used to inject a local no-interface view of an EJB into another managed bean, the generated proxy that is injected cannot resolve calls to methods implemented in the EJB's superclass that aren't overridden by the concrete EJB class.

      An outline of the simplified test case that demonstrates the problem is:

      // This can be any DI candidate in an EJB container. In this case it's a JSF2 backing bean
      // managed in a CDI context.
      public class InjectionSite {
      // If injected via @EJB, everything works, because we don't use Weld to create the proxy.
      @Inject private EJBClass ejb;
      public int getValue()

      { // Throws IllegalStateException from Weld return ejb.getValue(); }


      // The EJB its self has a method that's implemented by a superclass and
      // not overridden by the concrete EJB class.
      public class EJBClass extends EJBSuper

      { // Inherits getValue() from super }

      public class EJBSuper {
      public int getValue()

      { return 1; }


      This seems to come down to Weld's EnterpriseBeanProxyMethodHandler. It decides which EJB class to ask the container for an instance of by determining which class implements the method being called. If the implementation is in a superclass of the EJB, this will fail, because the container doesn't know anything about the EJB's superclass, and in any non-trivial case there'll be several different EJBs with the same superclass anyway.

      The test case functions correctly if modified to use the Glassfish native JSF2/EJB injection via @EJB instead of Weld injection with @Inject, as the proxy created by @EJB isn't the Weld proxy implementation. That's only an option if you're using JSF2, though.

      As a workaround, the concrete EJB can wrap the superclass's methods, but this is rather clumsy in real-world cases where the superclass exists for a reason, particularly for things like data access facades where the superclass contains generified DAO methods and subclasses only provide a type param and a few helpers.

      If the object being injected isn't an EJB, everything works fine, but that's not really an option if you need EJB features or if you're injecting a bean that can't be made serializable into a serializable object like a JSF2 session-scoped bean.

      Background here: http://forums.java.net/jive/thread.jspa?messageID=480532&#480532 . A test case is attached to the thread.

        Gliffy Diagrams




              • Assignee:
                pmuir Pete Muir
                ringerc Craig Ringer
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