There's no ObjectFactory with an @XmlElementDecl

So I was trying to use the OGC Schemas compiled with JAXB. I compiled them all and decided to test them with this class:

import net.opengis.sos.v_1_0_0.InsertObservation;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

public class JAXBTest {
    public static void main(String[] args) throws JAXBException {
        JAXBContext context = JAXBContext.newInstance(InsertObservation.class);
        InsertObservation insert = new InsertObservation();
        Marshaller mar = context.createMarshaller();
        mar.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        mar.marshal(insert, System.out);

    }
}

However it throws this unenlightening (for me at least) error:

There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/sensorML/1.0.1}_Process.
 this problem is related to the following location:
  at protected java.util.List net.opengis.om.v_1_0_0.ProcessPropertyType.content
  at net.opengis.om.v_1_0_0.ProcessPropertyType
  at public net.opengis.om.v_1_0_0.ProcessPropertyType net.opengis.om.v_1_0_0.ObjectFactory.createProcessPropertyType()
  at net.opengis.om.v_1_0_0.ObjectFactory
  at protected java.lang.Object net.opengis.om.v_1_0_0.AnyOrReferenceType.any
  at net.opengis.om.v_1_0_0.AnyOrReferenceType
  at protected net.opengis.om.v_1_0_0.AnyOrReferenceType net.opengis.om.v_1_0_0.ObservationType.metadata
  at net.opengis.om.v_1_0_0.ObservationType
  at protected net.opengis.om.v_1_0_0.ObservationType net.opengis.sos.v_1_0_0.InsertObservation.observation
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}temporalOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}spatialOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetObservation$FeatureOfInterest.spatialOps
  at net.opengis.sos.v_1_0_0.GetObservation$FeatureOfInterest
  at public net.opengis.sos.v_1_0_0.GetObservation$FeatureOfInterest net.opengis.sos.v_1_0_0.ObjectFactory.createGetObservationFeatureOfInterest()
  at net.opengis.sos.v_1_0_0.ObjectFactory
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}temporalOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetFeatureOfInterest$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetFeatureOfInterest$EventTime
  at public net.opengis.sos.v_1_0_0.GetFeatureOfInterest$EventTime net.opengis.sos.v_1_0_0.ObjectFactory.createGetFeatureOfInterestEventTime()
  at net.opengis.sos.v_1_0_0.ObjectFactory
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}temporalOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetObservation$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetObservation$EventTime
  at public net.opengis.sos.v_1_0_0.GetObservation$EventTime net.opengis.sos.v_1_0_0.ObjectFactory.createGetObservationEventTime()
  at net.opengis.sos.v_1_0_0.ObjectFactory
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}comparisonOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetObservation$Result.comparisonOps
  at net.opengis.sos.v_1_0_0.GetObservation$Result
  at public net.opengis.sos.v_1_0_0.GetObservation$Result net.opengis.sos.v_1_0_0.ObjectFactory.createGetObservationResult()
  at net.opengis.sos.v_1_0_0.ObjectFactory
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation
There's no ObjectFactory with an @XmlElementDecl for the element {http://www.opengis.net/ogc}spatialOps.
 this problem is related to the following location:
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetFeatureOfInterest$Location.spatialOps
  at net.opengis.sos.v_1_0_0.GetFeatureOfInterest$Location
  at protected net.opengis.sos.v_1_0_0.GetFeatureOfInterest$Location net.opengis.sos.v_1_0_0.GetFeatureOfInterest.location
  at net.opengis.sos.v_1_0_0.GetFeatureOfInterest
  at public net.opengis.sos.v_1_0_0.GetFeatureOfInterest net.opengis.sos.v_1_0_0.ObjectFactory.createGetFeatureOfInterest()
  at net.opengis.sos.v_1_0_0.ObjectFactory
  at protected javax.xml.bind.JAXBElement net.opengis.sos.v_1_0_0.GetResult$EventTime.temporalOps
  at net.opengis.sos.v_1_0_0.GetResult$EventTime
  at protected java.util.List net.opengis.sos.v_1_0_0.GetResult.eventTime
  at net.opengis.sos.v_1_0_0.GetResult
  at @javax.xml.bind.annotation.XmlSeeAlso(value=[class net.opengis.sos.v_1_0_0.DescribeFeatureType, class net.opengis.sos.v_1_0_0.DescribeResultModel, class net.opengis.sos.v_1_0_0.InsertObservation, class net.opengis.sos.v_1_0_0.DescribeSensor, class net.opengis.sos.v_1_0_0.GetObservationById, class net.opengis.sos.v_1_0_0.GetFeatureOfInterestTime, class net.opengis.sos.v_1_0_0.GetResult, class net.opengis.sos.v_1_0_0.RegisterSensor, class net.opengis.sos.v_1_0_0.GetObservation, class net.opengis.sos.v_1_0_0.DescribeObservationType, class net.opengis.sos.v_1_0_0.GetFeatureOfInterest])
  at net.opengis.sos.v_1_0_0.InsertObservation

After googling for a while I found this post on a mailing list. Now I am not a fan of editing auto-generated code, so I went looking for a better solution and read up on the documentation for the XmlSeeAlso annotation, specifically:

The user would be required to create JAXBContext as JAXBContext.newInstance(Dog.class,Cat.class)


Hmm... So after reading this I gave this a quick whirl:

import net.opengis.sensorml.v_1_0_1.ProcessChainType;
import net.opengis.sos.v_1_0_0.InsertObservation;
import net.opengis.sos.v_1_0_0.filter.v_1_1_0.BinaryTemporalOpType;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

public class JAXBTest {
    public static void main(String[] args) throws JAXBException {
        JAXBContext context = JAXBContext.newInstance(InsertObservation.class, BinaryTemporalOpType.class, ProcessChainType.class);
        InsertObservation insert = new InsertObservation();
        Marshaller mar = context.createMarshaller();
        mar.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        mar.marshal(insert, System.out);

    }
}

Yeah! Success:

The thing to note is that these two extra classes are not in the same package or jar file so cannot be found by the context loader, hence having to specifically add them.