Mapping xml to java Object using XmlPath

Below are the classes

@XmlRootElement(name = "response")
    @XmlAccessorType(XmlAccessType.FIELD)
    public class Response {
        @XmlElement(name = "result")
        private Result result;
    }

@XmlAccessorType(XmlAccessType.FIELD)
public class Results {

    @XmlElement(name="doc")
    private List<Doc> docs;
}

@XmlAccessorType(XmlAccessType.FIELD)
public class Doc {

    @XmlPath("int[@name='DOWNLOADCOUNT']/text()")
    private int count;
    @XmlPath("str[@name='TITLE']/text()")
    private String title;
    @XmlPath("str[@name='LANGUAGE']/text()")
    private String language;
    @XmlPath("str[@name='ALBUM']/text()")
    private String album;
    @XmlPath("str[@name='VODAFONERBTID']/text()")
    private String telRBTId;
    @XmlPath("arr[@name='SINGER']/str/text()")
    private String[] singers;
    @XmlPath("float[@name='score']/text()")
    private float score;
}

Here is the exception which I am getting

[Exception [EclipseLink-25008] (Eclipse Persistence Services - 2.5.0.v20130425-368d603): org.eclipse.persistence.exceptions.XMLMarshalException Exception Description: A descriptor with default root element response was not found in the project] at org.eclipse.persistence.jaxb.JAXBUnmarshaller.handleXMLMarshalException(JAXBUnmarshaller.java:980) at org.eclipse.persistence.jaxb.JAXBUnmarshaller.unmarshal(JAXBUnmarshaller.java:126) at com.sharique.application.Application.unMarshalling(Application.java:44) at com.sharique.main.TestMain.main(TestMain.java:53)