XML : Many to many xml

I am a beginner using hibernate. I have a userProfiles table and I want to create another table userTrack which has 2 userProfilesIds only. This table sets persmissions.

This is my user profile java class.

  public class UserProfileObject implements Serializable{        //private static final long serialVersionUID = 1L;      private Set<UserTrackObject> userTracks = new HashSet<UserTrackObject>(0);        private int UserProfileObjectId; // rest of attributes        public int getUserProfileObjectId() {          return UserProfileObjectId;      }        public void setUserProfileObjectId(int userProfileObjectId) {          UserProfileObjectId = userProfileObjectId;      }        public Set<UserTrackObject> getUserTracks() {            return userTracks;      }        public void setUserTracks(Set<UserTrackObject> userTracks) {          this.userTracks = userTracks;      }      //rest of getters and setters  }    

This is my UserTrack Class. The purpose of this table is to see if user 1 has permission to see user 2 details. Permission does not go both ways. for example one user x can see user y info but not the opposite.

  public class UserTrackObject implements Serializable {        private UserProfileObject userProfileObject;      private UserProfileObject userProfileObject1;        public UserProfileObject getUserProfileObject() {          return userProfileObject;      }      public void setUserProfileObject0(UserProfileObject userProfileObject) {          this.userProfileObject = userProfileObject;      }      public UserProfileObject getUserProfileObject1() {          return userProfileObject1;      }      public void setUserProfileObject1(UserProfileObject userProfileObject1) {          this.userProfileObject1 = userProfileObject1;      }    }    

This is my xml mapping file.

  <class name="objects.UserProfileObject" table="userProfiles">        <id name="UserProfileObjectId" column="UserProfileObjectId">          <generator class="native" />      </id>        <set name="userTracks" cascade="all" >          <key>              <column name="UserProfileObjectId" />          </key>          <many-to-many class="objects.UserTrackObject" />      </set>        <!-- rest of properties -->    </class>    <class name="objects.UserTrackObject" table="userTrack">        <composite-id>          <key-many-to-one name="userProfileObject" class="objects.UserProfileObject" >              <column name="UserProfileObjectId"/>          </key-many-to-one>          <key-many-to-one name="userProfileObject1" class="objects.UserProfileObject">              <column name="UserProfileObjectId"/>          </key-many-to-one>      </composite-id>  </class>