Я использую JAXB для unmarshalling XML файла для Java Object.
Этот XML содержит список. например
<items>
<item>
...
</item>
...
</items>
и Java Class имеют @XMLElementWrapper для элементов
@XMLElementWrapper(name="items")
@XMLElement(name="item")
private List<Item> items;
И я получаю исключение null-указателя, когда я пытаюсь разобрать.
java.lang.NullPointerException
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:54)
at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
at java.lang.reflect.Field.get(Field.java:379)
at com.sun.xml.bind.v2.runtime.reflect.Accessor$FieldReflection.get(Accessor.java:185)
at com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.startPacking(Lister.java:249)
at com.sun.xml.bind.v2.runtime.reflect.Lister$CollectionLister.startPacking(Lister.java:224)
at com.sun.xml.bind.v2.runtime.unmarshaller.Scope.add(Scope.java:78)
at com.sun.xml.bind.v2.runtime.property.ArrayERProperty$ReceiverImpl.receive(ArrayERProperty.java:150)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallingContext.endElement(UnmarshallingContext.java:404)
at com.sun.xml.bind.v2.runtime.unmarshaller.SAXConnector.endElement(SAXConnector.java:125)
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 com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:200)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:173)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:157)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:214)
at com.amazon.epubs.edition.manifest.serializer.JAXBMarshaller.unmarshall(JAXBMarshaller.java:45)
at amazon.PeriodicalsManagementService.handler.PreviewPublicationHandler.getFolioRenditions(PreviewPublicationHandler.java:293)
at amazon.PeriodicalsManagementService.handler.PreviewPublicationHandler.doMainProcessing(PreviewPublicationHandler.java:176)
... 19 more
Попробуйте с классом-оболочкой для List<>
:
@XmlRootElement
class Items {
@XmlElement
List<Item> item;
}
Затем сделайте unmarshall
для Items
xstream
. Почти похоже. Проверьте это здесь