@Entity

@Table(name = "TABLE_NAME")

@IdClass(PK.class)

public class TableName implements Serializable{

    @Id

    @Column(name="ID1")

    private String id1;

    @Id

    @Column(name="ID2")

    private String id2;

    @Column(name="OTHER")

    private String other;

public class PK implements Serializable {

    private String id1;

    private String id2;

}