Question

Java开发人员。我正在使用JAXB来创建绑定对象。当我尝试创建这样的JAXBContext时：

JAXBContext.newInstance("com.mycompany.jaxb.pkg1:com.mycompany.jaxb.pkg2");

我收到NullPointerException：

Exception in thread "main" java.lang.NullPointerException
    at com.sun.xml.bind.v2.model.impl.PropertyInfoImpl.calcXmlName(PropertyInfoImpl.java:287)
    at com.sun.xml.bind.v2.model.impl.PropertyInfoImpl.calcXmlName(PropertyInfoImpl.java:260)
    at com.sun.xml.bind.v2.model.impl.ElementPropertyInfoImpl.getTypes(ElementPropertyInfoImpl.java:100)
    at com.sun.xml.bind.v2.model.impl.RuntimeElementPropertyInfoImpl.getTypes(RuntimeElementPropertyInfoImpl.java:50)
    at com.sun.xml.bind.v2.model.impl.ElementPropertyInfoImpl$1.size(ElementPropertyInfoImpl.java:42)
    at java.util.AbstractList$Itr.hasNext(AbstractList.java:416)
    at com.sun.xml.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:139)
    at com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:49)
    at com.sun.xml.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:41)
    at com.sun.xml.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:189)
    at com.sun.xml.bind.v2.model.impl.RegistryInfoImpl.<init>(RegistryInfoImpl.java:63)
    at com.sun.xml.bind.v2.model.impl.ModelBuilder.addRegistry(ModelBuilder.java:232)
    at com.sun.xml.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:201)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl$3.run(JAXBContextImpl.java:357)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl$3.run(JAXBContextImpl.java:351)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:350)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:216)
    at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:76)
    at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:55)
    at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:124)
    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:592)
    at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:132)
    at javax.xml.bind.ContextFinder.find(ContextFinder.java:286)
    at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:372)
    at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:337)
    at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:244)
    at com.mycompany.jaxb.JAXBContextFactory.initIfNeeded(JAXBContextFactory.java:66)

谷歌搜索相关的关键字让我有几个讨论线程说这是一个已知的错误，我应该升级到2.0.3版本。但这是我的maven POM文件：

<dependency>
  <groupId>com.sun.xml.bind</groupId>
  <artifactId>jaxb-impl</artifactId>
  <version>2.2.1</version>
</dependency>
<dependency>
  <groupId>javax.xml.bind</groupId>
  <artifactId>jaxb-api</artifactId>
  <version>2.1</version>
</dependency>

...正如您所看到的，我已经超越了2.0.3版。（是的，我尝试回滚到旧版本;它没有帮助。）

有没有人因为2.0.2或更高版本以外的原因而看到这个，或者是否有人指出如何追踪问题？

Answer 1

好的，记录：我找到了解决方案。

正如几个线程所暗示的那样，这个bug的来源是使用了早于2.0.2的JAXB版本。我的错误是我的maven POM文件被另一个导入旧版本库的POM文件覆盖。

感谢skaffman和其他所有人一起来看看。

JAXBContext.newInstance（）中的NullPointerException

1 个答案: