I'm trying to get a Map relation to work with a referenced Key....i.e the Key is another entity bean:

@Entity
@Table (name="ship")
@NamedQuery(name="ship.getAll", query="from Ship sh")
public class Ship {

 .....

 @CollectionOfElements (fetch = FetchType.EAGER)
 @MapKey(name="nameid")
 public Map<AttributeName,Attribute> getAttributes() {
 if((attributes) == null) attributes = new HashMap<AttributeName,Attribute>();
 return attributes;
 }

 public void setAttributes(Map<AttributeName,Attribute> attributes) {
 this.attributes = attributes;
 }

 private int id;
 private Map<AttributeName,Attribute> attributes;

}

public class Attribute {

 @Id @GeneratedValue(strategy= GenerationType.AUTO)
 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 @ManyToOne (cascade = {CascadeType.ALL})
 public AttributeName getNameid() {
 return nameid;
 }

 public void setNameid(AttributeName nameid) {
 this.nameid = nameid;
 }

 public String getValue() {
 return value;
 }

 public void setValue(String value) {
 this.value = value;
 }

 @ManyToOne (cascade = {CascadeType.PERSIST})
 public Ship getShip(){
 return ship;
 }

 public void setShip(Ship ship) {
 this.ship = ship;
 }

 public long getStartdate() {
 return startdate;
 }

 public void setStartdate(long startdate) {
 this.startdate = startdate;
 }

 public long getEnddate() {
 return enddate;
 }

 public void setEnddate(long enddate) {
 this.enddate = enddate;
 }

 private Ship ship;
 private int id;
 private AttributeName nameid;
 private String value;
 private long startdate;
 private long enddate;

}

@Entity
@Table (name="attributename")
public class AttributeName {

 @Id @GeneratedValue(strategy= GenerationType.AUTO)
 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 //Name of the attribute
 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }

 @CollectionOfElements
 public Collection<Attribute> getAttr() {
 if((attr) == null) attr = new ArrayList<Attribute>();
 return attr;
 }

 public void setAttr(Collection<Attribute> attr) {
 this.attr = attr;
 }

 private Collection<Attribute> attr;
 private int id;
 private String name;

}

and I get the following exception on deploy:

Caused by: org.hibernate.MappingException: Could not determine type for: com.sms.srs.entity.AttributeName, for columns: [org.hibernate.mapping.Formula( nameid_id )]
 at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:266)
 at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:253)
 at org.hibernate.mapping.IndexedCollection.validate(IndexedCollection.java:68)
 at org.hibernate.cfg.Configuration.validate(Configuration.java:988)
 at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1169)
 at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:414)
 at org.hibernate.ejb.Ejb3Configuration.createEntityManagerFactory(Ejb3Configuration.java:575)
 at org.hibernate.ejb.Ejb3Configuration.createContainerEntityManagerFactory(Ejb3Configuration.java:245)
 at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:108)
 at org.jboss.ejb3.entity.PersistenceUnitDeployment.start(PersistenceUnitDeployment.java:260)

To clarify, a ship should have a map of attributename -> attribute
The attributename class has to be used rather than a string so that key uniqueness is maintained (I tested it with String and it worked fine....it seems to be something to do with AttributeName).

I don't see where I'm missing notion, help appreciated!!

Thanks.