Question

当我的JAXBElement有多个子元素时，我得到了这个异常。我如何确定如何确定导致此异常的子元素？

java.lang.NullPointerException
    at com.sun.xml.bind.v2.runtime.property.AttributeProperty.getIdValue(AttributeProperty.java:128)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.getId(ClassBeanInfoImpl.java:320)
    at com.sun.xml.bind.v2.runtime.reflect.TransducedAccessor$IDREFTransducedAccessorImpl.print(TransducedAccessor.java:290)
    at com.sun.xml.bind.v2.runtime.reflect.TransducedAccessor$IDREFTransducedAccessorImpl.print(TransducedAccessor.java:271)
    at com.sun.xml.bind.v2.runtime.property.AttributeProperty.serializeAttributes(AttributeProperty.java:101)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeAttributes(ClassBeanInfoImpl.java:375)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:689)
    at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:158)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:158)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.ArrayElementNodeProperty.serializeItem(ArrayElementNodeProperty.java:69)
    at com.sun.xml.bind.v2.runtime.property.ArrayElementProperty.serializeListBody(ArrayElementProperty.java:172)
    at com.sun.xml.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:159)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:158)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:161)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:131)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeBody(ElementBeanInfoImpl.java:333)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:340)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:76)
    at com.sun.xml.bind.v2.runtime.property.SingleReferenceNodeProperty.serializeBody(SingleReferenceNodeProperty.java:115)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:158)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:158)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.property.ArrayElementNodeProperty.serializeItem(ArrayElementNodeProperty.java:69)
    at com.sun.xml.bind.v2.runtime.property.ArrayElementProperty.serializeListBody(ArrayElementProperty.java:172)
    at com.sun.xml.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:159)
    at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:358)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:696)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:156)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:131)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeBody(ElementBeanInfoImpl.java:333)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:340)
    at com.sun.xml.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:76)
    at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:494)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:323)
    at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:251)
    at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:75)
    at com.tdsecurities.fxdev.doddfranktdmladapter.SwapTDMLGeneratorJunitTest.testHello(SwapTDMLGeneratorJunitTest.java:113)

这是我用来编组Jaxbelment的代码：

JAXBElementdmlJAXBElement = SwapDMLGenerator.generateDML（event，leg1ordMm，leg2ordMm， leg1OrdCs，leg2OrdCs）;

JAXBContext jaxbContext_m = JAXBContext.newInstance(DmlWrapper.class);
Marshaller marshaller = jaxbContext_m.createMarshaller();
//marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, "");
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);        
String  outFileName= String.format("dml-%d-ordm_deallnum-%s.xml",System.currentTimeMillis(), .getDealNumber());
File fout= new File(destDir, outFileName);
FileOutputStream fos= new FileOutputStream(fout);
marshaller.marshal(dmlJAXBElement, fos);
fos.close();

Answer 1

我能想到的一种方法是在项目中包含JAXB的源代码，在调试模式下运行程序并在eclipse中放置一个条件断点。见How to set a conditional break point in eclipse 条件是该属性为null，因为您正在获得NPE。然后，当执行在此时停止时，您可以检查相应的变量。

其他替代方法是查看增加日志级别是否为您提供更多信息。

Answer 2

使用Eclipse IDE，可以调试一些第三方代码，例如Sun的JAXB实现。

在Eclipse中，尝试以下两个块：

启用第三方调试支持

Search for class AttributeProperty inside your classpath entry for JRE System Library
In Outline tab, expand class file and respective class inside this
Right-Click on target method (in this case: AttributeProperty.getIdValue)
Click on: Toggle Method Breakpoint

检查哪些字段有问题：

启用“调试”选项卡和“变量”选项卡
与其他调试过程一样，以调试模式启动测试
当程序实现相关断点时，请检查“变量”选项卡＆＃39;这个＆＃39;和＆＃39; arg0＆＃39;引用。这些引用包含有关当前节点和编组对象的信息

在这一点上，您已准备好上下文进行分析和调试。

我处理相同的JAXB / IDREF问题并且还没有任何解决方案。我正在检查它。

你解决了这个问题吗？

最诚挚的问候，

过去

在JAXB编组中，如何识别导致JAXB编组异常的子元素？

2 个答案: