JPA Mapping Error -not provided sufficient metadata in your id class

I am trying to do mapping in JPA.

@Entity
public class Auction {

    @Id
    private Integer auctionId;

    @OneToMany(mappedBy="auctionId")
    @MapKey(name="auctionParamId")
    private Map<AuctionParam, AuctionParamValue> values;

}

@Entity
public class AuctionParam {

    @Id
    private Integer auctionParamId;

    private String description;

}

@Entity
public class AuctionParamValue {

    @EmbeddedId
    private AuctionParamValuePK pk;

    private String value;

}

@Embeddable
public class AuctionParamValuePK {

    @ManyToOne
    @JoinColumn(name="auctionId")
    private Auction auction;

    @ManyToOne
    @JoinColumn(name="auctionParamId")
    private AuctionParam auctionParam;

}

Showing an error:-

.Error-Details:-Exception Description: Entity [class com.eaportal.domain.AuctionPar开发者_开发技巧amValue]

uses [class com.eaportal.domain.AuctionParamValuePK]

as embedded id class

whose access-type has been determined as [FIELD].

But [class com.eaportal.domain.AuctionParamValuePK]

does not define any [FIELD]. It is likely that you have not provided

sufficient metadata in your id class [class com.eaportal.domain.AuctionParamValuePK].

If you come up with a solution please let me know.

Thanks in Advance Tushar

You cannot use an EmbeddedId with relationships. Use an IdClass.

@Entity
@IdClass(AuctionParamValuePK.class)
public class AuctionParamValue {

    @Id
    @ManyToOne
    @JoinColumn(name="auctionId")
    private Auction auction;

    @Id
    @ManyToOne
    @JoinColumn(name="auctionParamId")
    private AuctionParam auctionParam;

    @Basic
    private String value;

}

public class AuctionParamValuePK {

    private int auction;
    private int auctionParam;

}

I think there are some errors in your Auction class. This is how I think it should look

@Entity
public class Auction {

    @Id
    private Integer auctionId;

    @OneToMany(mappedBy="auction") // not auctionId
    @MapKey(name="auctionParam") // not auctionParamId
    private Map<AuctionParam, AuctionParamValue> values;

}

(The annotation values have to correspond with fields (or properties), not with columns)