JAXB: Generic Polymorphism

Question

I am trying to use JAXB (inside Jersey) for polymorphism with generics:

@XmlRootElement public class Performance<M extends IMeasurement> { @XmlAnyElement private List<M> measurement; } 

 @XmlJavaTypeAdapter(MeasurementAbstract.Adapter.class) public interface IMeasurement<D extends Serializable, V extends Number> extends Serializable { D getDate(); void setDate(D date); V getValue(); void setValue(V value); } 

 @XmlTransient @XmlAccessorType(XmlAccessType.FIELD) @XmlSeeAlso({MeasurementStringDouble.class, MeasurementStringInteger.class}) public abstract class MeasurementAbstract<D extends Serializable, V extends Number> implements IMeasurement<D, V> { @XmlElement protected D date; @XmlElement protected V value; static class Adapter extends XmlAdapter<MeasurementAbstract, IMeasurement> { public IMeasurement unmarshal(MeasurementAbstract m) { return m; } public MeasurementAbstract marshal(IMeasurement v) { return (MeasurementAbstract) v; } } } 

 @XmlRootElement public class MeasurementStringDouble extends MeasurementAbstract<String, Double> {} @XmlRootElement public class MeasurementStringInteger extends MeasurementAbstract<String, Integer> {} 

I have this error:

GRAVE: Fixed exception for response: 500 (Internal server error) javax.ws.rs.WebApplicationException: javax.xml.bind.MarshalException - with associated exception: [javax.xml.bind.JAXBException: class org.test.jaxb.MeasurementStringDouble or any of its superclasses known to this context.]

Answer 1

I found a solution to solve this problem:

 @XmlRootElement public class Performance<M extends IMeasurement> { @XmlElementWrapper(name = "measurementsPerformance") @XmlElements({ @XmlElement(name = "measurement", type = MeasurementStringDouble.class), @XmlElement(name = "measurement", type = MeasurementStringInteger.class)}) private List<M> measurement; } 

 public interface IMeasurement<D extends Serializable, V extends Number> extends Serializable { D getDate(); void setDate(D date); V getValue(); void setValue(V value); } 

 @XmlTransient public abstract class MeasurementAbstract<D extends Serializable, V extends Number> implements IMeasurement<D, V>, Serializable { protected D date; protected V value; } 

 @XmlRootElement @XmlAccessorType(XmlAccessType.PROPERTY) public class MeasurementStringDouble extends MeasurementAbstract<String, Double> { @XmlElement @Override public String getDate() { return date; } @XmlElement @Override public Double getValue() { return value; } } @XmlRootElement @XmlAccessorType(XmlAccessType.PROPERTY) public class MeasurementStringInteger extends MeasurementAbstract<String, Integer> { @XmlElement @Override public String getDate() { return date; } @XmlElement @Override public Integer getValue() { return value; } } 

The disadvantage of this solution is duplication of getters / setters in subclasses.