MarshalException when marshalling Generic classes

I have the sample generic classes which are JAXB annotated.

package org.jboss.resteasy.examples.springmvc;

@XmlRootElement(name="contactG")
@XmlAccessorType(XmlAccessType.FIELD)
public class ContactG<T> {

@XmlElement
private T entity;

public ContactG()

{ super(); }

public ContactG(T entity)

{ super(); this.entity = entity; }

public T getEntity()

{ return entity; }

public void setEntity(T entity)

{ this.entity = entity; }

}

package org.jboss.resteasy.examples.springmvc;

@XmlRootElement(name="contact")
@XmlAccessorType(XmlAccessType.FIELD)
public class Contact
{
@XmlElement
private String firstName;

@XmlElement
private String lastName;

public Contact()
{
}

public Contact(String firstName, String lastName)

{ this.firstName = firstName; this.lastName = lastName; }

public String getFirstName()

{ return firstName; }

public void setFirstName(String firstName)

{ this.firstName = firstName; }

public String getLastName()

{ return lastName; }

public void setLastName(String lastName)

{ this.lastName = lastName; }

}

And when I execute this code it throws me the exception.

JAXBContext ctx = JAXBContext.newInstance(ContactG.class);
StringWriter str = new StringWriter();
ContactG<Contact> contact = new ContactG<Contact>(new Contact("fffff", "sfsfds"));
ctx.createMarshaller().marshal(contact, str);

System.out.println(str);

The exception is

javax.xml.bind.MarshalException

• with linked exception:
  [javax.xml.bind.JAXBException: class org.jboss.resteasy.examples.springmvc.Contact nor any of its super class is known to this context.]
  at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:318)
  at com.sun.xml.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:244)
  at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(Unknown Source)
  at org.jboss.resteasy.examples.springmvc.ContactsTest.testG(ContactsTest.java:135)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
  at java.lang.reflect.Method.invoke(Unknown Source)
  at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:59)
  at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)
  at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)
  at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)
  at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)
  at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)
  at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)
  at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)
  at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)
  at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)
  at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)
  at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
  at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
  at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
  Caused by: javax.xml.bind.JAXBException: class org.jboss.resteasy.examples.springmvc.Contact nor any of its super class is known to this context.
  at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:246)
  at com.sun.xml.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:261)
  at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:653)
  at com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:152)
  at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:332)
  at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsSoleContent(XMLSerializer.java:593)
  at com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:320)
  at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:494)
  at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:315)
  ... 25 more
  Caused by: javax.xml.bind.JAXBException: class org.jboss.resteasy.examples.springmvc.Contact nor any of its super class is known to this context.
  at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getBeanInfo(JAXBContextImpl.java:590)
  at com.sun.xml.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:648)
  ... 31 more