Description David McCann 2010-09-15 12:48:24 EDT

If the target xpath in an object reference mapping is invalid, the following exception is thrown:

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javax.xml.bind.UnmarshalException
 - with linked exception:
[java.lang.NullPointerException]
	at org.eclipse.persistence.jaxb.JAXBUnmarshaller.unmarshal(JAXBUnmarshaller.java:129)
	at org.eclipse.persistence.testing.jaxb.externalizedmetadata.xmljoinnode.XmlJoinNodeTestCases.testUnmarshal(XmlJoinNodeTestCases.java:133)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at junit.framework.TestCase.runTest(TestCase.java:168)
	at junit.framework.TestCase.runBare(TestCase.java:134)
	at junit.framework.TestResult$1.protect(TestResult.java:110)
	at junit.framework.TestResult.runProtected(TestResult.java:128)
	at junit.framework.TestResult.run(TestResult.java:113)
	at junit.framework.TestCase.run(TestCase.java:124)
	at junit.framework.TestSuite.runTest(TestSuite.java:232)
	at junit.framework.TestSuite.run(TestSuite.java:227)
	at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:79)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.NullPointerException
	at org.eclipse.persistence.oxm.mappings.XMLObjectReferenceMapping.buildReference(XMLObjectReferenceMapping.java:176)
	at org.eclipse.persistence.internal.oxm.XMLObjectReferenceMappingNodeValue.attribute(XMLObjectReferenceMappingNodeValue.java:92)
	at org.eclipse.persistence.oxm.record.UnmarshalRecord.startElement(UnmarshalRecord.java:720)
	at org.eclipse.persistence.internal.oxm.record.XMLStreamReaderReader.parseEvent(XMLStreamReaderReader.java:104)
	at org.eclipse.persistence.internal.oxm.record.XMLStreamReaderReader.parse(XMLStreamReaderReader.java:79)
	at org.eclipse.persistence.internal.oxm.record.XMLStreamReaderReader.parse(XMLStreamReaderReader.java:69)
	at org.eclipse.persistence.internal.oxm.record.SAXUnmarshaller.unmarshal(SAXUnmarshaller.java:650)
	at org.eclipse.persistence.oxm.XMLUnmarshaller.unmarshal(XMLUnmarshaller.java:598)
	at org.eclipse.persistence.jaxb.JAXBUnmarshaller.unmarshal(JAXBUnmarshaller.java:438)
	at org.eclipse.persistence.jaxb.JAXBUnmarshaller.unmarshal(JAXBUnmarshaller.java:126)
	... 20 more

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The offending lines of code start at 170 of XMLObjectReferenceMapping:

XMLField tgtFld = (XMLField)
     getSourceToTargetKeyFieldAssociations().get(xmlField);

int idx = pkFieldNames.indexOf(tgtFld.getXPath());

Object value = 
   session.getDatasourcePlatform().getConversionManager().
   convertObject(object, 
   referenceDescriptor.getTypedField(tgtFld).getType());


Since tgtFld is null, the following call causes a null pointer:

    referenceDescriptor.getTypedField(tgtFld).getType()

We should be checking the target xpaths in the initialize method of XMLObjectReferenceMapping, and presumably XMLCollectionReferenceMapping as well (unless the ORM init suffices due to inheritance).

One thing to consider when validating target xpaths is that in the case of an Embeddable Key Class, the reference descriptor will not have a field for the given xpath, but the embeddable key class will.