The JAXB unmarshaller does not expect setters for properties of type
List<?>; it'll
just use x.getSomeList().add( y ) to add another child. See this
example<
http://jaxb.java.net/tutorial/section_2_2_7-Defining-a-List-of-Integers.html#Defining%20a%20List%20of%20Integers>for
the typical way
getters for lists are written (and there are several good reasons for doing
it this way).
-W
On 18 May 2011 19:35, Philippe Rolet <philippe.rolet_at_digimind.com> wrote:
> Dear JAXB users,
> I am using JAXB to marshal/unmarshal some java classes and I recently came
> accross an issue (details attached below).
>
> I am trying to deserialize an XML file provided by a third party. The XML
> validates against the schema that I generated from my java classes using
> jaxb's schemagen tool without trouble. Then, when unmarshalling it, the
> following exception occurs:
>
> java.lang.NullPointerException
> at
> com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.addToPack(Lister.java:305)
> at
> com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.addToPack(Lister.java:269)
> ... (see below for full stack trace)
>
> Since the XML validates against a schema generated automatically by
> schemagen, I thought that no unmarshalling error could happen (I also
> checked that all requiered classes are known to the JAXBContext). I tried to
> search for the cause to this error on the net but I failed. I tried to see
> what was happening in the source, and the only thing I grasped is that an
> object was added to a "pack" field in Lister$CollectionLister that was not
> initialized (hence the nullpointerexception).
>
> Do you have any idea for the cause of this? is there an error in the XML
> document that validation may have missed? did I miss something in the way I
> unmarshal the object? Can you please help me solve the issue or find a
> workaround?
>
> Below are the functions that I wrote where the unmarshalling error happens,
> and attached are the classes for which the problem occurs, the schema
> generated from them, and the XML document that makes unmarshalling fail.
>
> I am using JAXB jar artifact from the maven repository jaxb-impl-2.2.2.
>
> Thank you very much for your help,
>
> Best wishes,
> Philippe Rolet
>
> Code:
>
> SemanticData res;
> try {
> String response=Tools.inputStreamToString(resp.getEntityInputStream());
> Tools.validateXML(response,
> applicationContext.getResource("classpath:"+outputSchema).getURL()); ==> XML
> validation, no error
> => error here res=Tools.xmlToObject(SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI).newSchema(applicationContext.getResource("classpath:"+outputSchema).getURL()),
> response ,SemanticData.class);
>
> } catch (JAXBException e) {
> throw new ExtractorException("Could not convert XML response to
> object.",e);
> }
>
> @SuppressWarnings("unchecked")
> public static <T> T xmlToObject(Schema schema, String xmlString,Class<T>
> objectClass) throws JAXBException {
> JAXBContext context= JAXBContext.newInstance(objectClass);
> Unmarshaller m=context.createUnmarshaller();
> m.setSchema(schema);
> =>error return (T)m.unmarshal(new StringReader(xmlString));
> }
>
>
> Full stack trace:
> java.lang.NullPointerException
> at
> com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.addToPack(Lister.java:305)
> at
> com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.addToPack(Lister.java:269)
> at com.sun.xml.bind.v2.runtime.unmarshaller.Scope.add(Scope.java:121)
> at
> com.sun.xml.bind.v2.runtime.property.ArrayERProperty$ReceiverImpl.receive(ArrayERProperty.java:213)
> at
> com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.endElement(UnmarshallingContext.java:523)
> at
> com.sun.xml.bind.v2.runtime.unmarshaller.ValidatingUnmarshaller.endElement(ValidatingUnmarshaller.java:107)
> at
> com.sun.xml.bind.v2.runtime.unmarshaller.SAXConnector.endElement(SAXConnector.java:160)
> at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
> at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanEndElement(Unknown
> Source)
> at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown
> Source)
> at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown
> Source)
> at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
> at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
> at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
> at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
> at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
> at
> com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:216)
> at
> com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:189)
> at
> javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:137)
> at
> javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:194)
> at com.digimind.wma.services.Tools.xmlToObject(Tools.java:99)
> at
> com.digimind.wma.services.extractor.ExtractorConnectorDDImpl.tagDocument(ExtractorConnectorDDImpl.java:68)
> at
> com.digimind.wma.services.test.ExtractorConnectorDDImplTest.testTagDocumentValidResult(ExtractorConnectorDDImplTest.java:63)
> 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
> org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
> at
> org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
> at
> org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
> at
> org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
> at
> org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
> at
> org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
> at
> org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
> at
> org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82)
> at
> org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
> at
> org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:240)
> at
> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:44)
> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:180)
> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:41)
> at org.junit.runners.ParentRunner$1.evaluate(ParentRunner.java:173)
> at
> org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
> at
> org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
> at
> org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
> at
> org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
> at org.junit.runners.ParentRunner.run(ParentRunner.java:220)
> at
> org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
> at
> org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
> 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)
>
>