NullPointerException in JAXBContext.newInstance()

Java developer here. I am using JAXB to create bind objects. When I attempt to create a JAXBContext like this:

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

I get a 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开发者_运维技巧.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)

Googling for the relevant keywords led me to several discussion threads saying that this is a known bug and I should upgrade to version 2.0.3. But here is my maven POM file:

<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>

...as you can see, I am already beyond version 2.0.3. (And yes, I tried rolling back to the old version; it didn't help.)

Has anyone seen this for a reason OTHER than version 2.0.2 or older, or does anyone have pointers for how to go about tracking down the problem?

Okay, for the record: I found the solution.

As several threads had suggested, the source of this bug was using a version of JAXB which was older than 2.0.2. My error was that my maven POM file was being overridden by another POM file which was importing an older version of the library.

Thanks to skaffman, and everyone else who took a look.