public class User{
   private Long userId;
   private Set<Attribute> attributes;

  @ManyToMany(fetch = FetchType.LAZY, cascade = {javax.persistence.CascadeType.DETACH})
   @Cascade({CascadeType.DELETE_ORPHAN, CascadeType.SAVE_UPDATE})
   @JoinTable(name = "tz_userattributes",
         joinColumns = @JoinColumn(name = "userId"),
         inverseJoinColumns = @JoinColumn(name = "attributeId"))
  public Set<Attribute> getAttributes() {
      return attributes;
  }
}

@Entity(name = "Attribute")
@Table(name = "tz_attribute")
public class Attribute extends {
   private Long attributeId;
   private String value;

   @Id
   @GeneratedValue(strategy = GenerationType.AUTO)
   public Long getAttributeId() {
      return attributeId;
   }

   public void setAttributeId(Long attributeId) {
      this.attributeId = attributeId;
   }

      this.type = type;
   }

   public String getValue() {
      return value;
   }

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

}