PM11461: NullPointerException when custom validator sets a target on an u nresolved proxy

APAR status

• Closed as program error.

Error description

• Description:
  NullPointerException when custom validator sets a target on an u
  nresolved proxy
  When this error arises, the validation stops completely. It also
   seems that the ID of the validation listener is not replaced in
   the error message.
  
  
  Message:
  An exception occurred while initializing and informing a validat
  ion listener with id {0}. The listener has been removed for this
   session.
  
  Exception stack trace:
  
  java.lang.NullPointerException
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter.addElementIdsToMarkerAttributeMap(A
  bstractValidationMarkerPresenter.java:149)
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter.createMarkerDescriptor(AbstractVali
  dationMarkerPresenter.java:132)
  at com.ibm.xtools.modeler.ui.internal.ui.views.tasklist.Validati
  onProblemsReporter.createMarkerDescriptor(ValidationProblemsRepo
  rter.java:254)
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter.createMarker(AbstractValidationMark
  erPresenter.java:297)
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter.createMarkers(AbstractValidationMar
  kerPresenter.java:1186)
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter$BuildMarkerData$2.run(AbstractValid
  ationMarkerPresenter.java:396)
  at org.eclipse.gmf.runtime.emf.core.internal.domain.MSLTransacti
  onalEditingDomain.runExclusive(MSLTransactionalEditingDomain.jav
  a:339)
  at org.eclipse.gmf.runtime.emf.core.internal.domain.MSLEditingDo
  main.runExclusive(MSLEditingDomain.java:2656)
  at com.ibm.xtools.emf.validation.core.presentation.markers.Abstr
  actValidationMarkerPresenter$BuildMarkerData.execute(AbstractVal
  idationMarkerPresenter.java:394)
  at com.ibm.xtools.modeler.ui.internal.ui.views.tasklist.Validati
  onProblemsReporter$BatchBuildMarkerData.execute(ValidationProble
  msReporter.java:469)
  at com.ibm.xtools.modeler.ui.internal.ui.views.tasklist.Validati
  onProblemsReporter.validationEvent(ValidationProblemsReporter.ja
  va:164)
  at com.ibm.xtools.emf.validation.core.internal.ValidationManager
  .validationOccurred(ValidationManager.java:312)
  at org.eclipse.emf.validation.service.ModelValidationService.bro
  adcastValidationEvent(ModelValidationService.java:309)
  at org.eclipse.emf.validation.internal.service.AbstractValidator
  .validate(AbstractValidator.java:160)
  at org.eclipse.emf.validation.internal.service.BatchValidator.va
  lidate(BatchValidator.java:120)
  at com.ibm.xtools.modeler.ui.internal.commands.ValidateCommand.d
  oExecuteWithResult(ValidateCommand.java:115)
  at org.eclipse.gmf.runtime.common.core.command.AbstractCommand.e
  xecute(AbstractCommand.java:135)
  at org.eclipse.core.commands.operations.DefaultOperationHistory.
  execute(DefaultOperationHistory.java:511)
  at org.eclipse.gmf.runtime.emf.ui.action.AbstractModelActionDele
  gate.execute(AbstractModelActionDelegate.java:168)
  at com.ibm.xtools.modeler.ui.internal.ui.actions.ValidateActionD
  elegate.doRun(ValidateActionDelegate.java:84)
  at org.eclipse.gmf.runtime.common.ui.action.AbstractActionDelega
  te.run(AbstractActionDelegate.java:391)
  at org.eclipse.gmf.runtime.emf.ui.action.AbstractModelActionDele
  gate.access$0(AbstractModelActionDelegate.java:1)
  at org.eclipse.gmf.runtime.emf.ui.action.AbstractModelActionDele
  gate$1.run(AbstractModelActionDelegate.java:73)
  at org.eclipse.gmf.runtime.emf.core.internal.domain.MSLTransacti
  onalEditingDomain.runExclusive(MSLTransactionalEditingDomain.jav
  a:339)
  at org.eclipse.gmf.runtime.emf.core.internal.domain.MSLEditingDo
  main.runExclusive(MSLEditingDomain.java:2656)
  at org.eclipse.gmf.runtime.emf.ui.action.AbstractModelActionDele
  gate.run(AbstractModelActionDelegate.java:70)
  at org.eclipse.gmf.runtime.common.ui.action.ActionManager$2.run(
  ActionManager.java:294)
  at org.eclipse.jface.operation.ModalContext$ModalContextThread.r
  un(ModalContext.java:121)
  
  
  
  
  
  Steps to reproduce:
  1. Create a new 'Model Validation' project (Examples ? RMP ? UML
   Modeler ? Model Validation)
  2. In 'JavaExample.java', replace the 'validate' code by the one
   below (just a demo code to create a Status on an unresolved pro
  xy):
  
    if (target instanceof Classifier)
    {
     Classifier clazz = (Classifier)target;
     ArrayList?EObject? myCollection = new ArrayList?EObject?();
     myCollection.add(clazz.getAttributes().get(0).getType());
     return ConstraintStatus.createStatus(ctx, clazz.getAttributes
  ().get(0).getType(), ctx.getResultLocus(), 'ERROOOOR', (Object)n
  ull);
    }
  3. Run as Eclipse app.
  4. In the runtime workbench, create 2 UML projects, with a class
   in each model
  5. In the first model, create an attribute, and set its type to
  the class in the other project.
  6. Close the first project, and delete the class in the second o
  ne: This will create an unresolved proxy on the type of the attr
  ibute.
  7. Reopen the first project, and validate. You get this error.
  
  
  Workaround:
  
  Manually check if the target is a proxy in the code.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  NullPointerException when custom validator sets a target on
  an unresolved proxy.  We can prevent the NPE at that point,
  however the customer is using the framework incorrectly.
  They should be marking the attribute that references the
  missing type, not the missing type itself.
  

Problem conclusion

• We can prevent the NPE at that point. They should be marking
  the attribute that references the missing type, not the
  missing type itself.
  
  Moved the declaration and intialization of a local variable
  so that it was NPE checked.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  SW MODELER WIN

• Fixed component ID

  5724I6901

Applicable component levels

• R754 PSN

     UP