XML to JavaBean

The XML file is following:

<AuthnRequest xmlns="A" ID="B">
    <Issuer xmlns="A">SOMETHING</Issuer>
    <NameIDPolicy Format="B" AllowCreate="true"/>
</AuthnRequest>

So how to transform this file with many attributes to a Javabean?

I tired this like this but didn't work

@XmlRootElement(name="AuthnRequest")
@XmlAccessorType(XmlAccessType.FIELD)
public class UserAuthn {

    @XmlAttribute
    private String xmlns;
    @XmlAttribute   
    private String ID;
    @XmlAttribute
    private String Version;
    @XmlAttribute
    private String IssueInstant;
    @XmlElement
    private List<Issuer> Issuers;
    @XmlElement
    private List<NameIDPolicy> NameIDPolicys;

    // Getters and Setters
}

Class Issuer

private String xmlns;

@XmlAttribute
public String getXmlns() {
    return xmlns;
}

public void setXmlns(String xmlns) {
    this.xmlns = xmlns;
}

Class NameIDPolicy is the same :

private String Format;
private String AllowCreate;

@XmlAttribute(name="AllowCreate")
public String getFormat() {
    return Format;
}

public void setFormat(String format) {
    Format = format;
}
@XmlAttribute(name="Format")
public String getAllowCreate() {
    return AllowCreate;
}

public void setAllowCreate(String allowCreate) {
    AllowCreate = allowCreate;
}

And the error is

threw exception [Request processing failed; nested exception is javax.xml.bind.UnmarshalException: unexpected element (uri:"A", local:"AuthnRequest"). Expected elements are <{}AuthnRequest>] with root cause