JSON representation - XML RootElement

I have a bean class as following

@XmlRootElement(name="Student")
public class Student {
  String id;
  String name;
  // Getter setters
}

And my JAX-RS class:

@GET
@Path("ex")
@Produces({MediaType.TEXT_XML, MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON })
public Student exGet() {
  return retunrStud("1"); // Will return student object
}

The out put for this XML

<Student>
  <age>23</age>
  <id>1</id>
  <name>PP1</name>
</Student>

JSON:

{"id":"1","name":"PP1","age":"23"}

The Root for JSON is not returned. How to solve this.

I'm using jersey-bundles and deploying it in Tom cat server.