I just need to add an entry on a many to many table/object with hibernate (associate a song to a playlist) called SongsPlaylist.
the structure of the tables is so defined: Songs---->SongPlaylist<----Playlists
the mapping files (omitted not important portion of file):
<hibernate-mapping>
<class name="model.pojo.Songs" table="songs" catalog="dbname" lazy="false">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="identity" />
</id>
<set name="songsPlaylists" table="songs_playlist" inverse="true" lazy="true" fetch="select">
<key>
<column name="song" not-null="true" unique="true" />
</key>
<one-to-many class="model.pojo.SongsPlaylist" />
</set>
</class>
</hibernate-mapping>
<!-- Generated 24-set-2014 8.40.14 by Hibernate Tools 3.6.0 -->
<hibernate-mapping>
<class name="model.pojo.SongsPlaylist" table="songs_playlist" catalog="dbname" lazy="false">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="identity" />
</id>
<many-to-one name="songs" class="model.pojo.Songs" fetch="select">
<column name="song" not-null="true" unique="true" />
</many-to-one>
<many-to-one name="playlists" class="model.pojo.Playlists" fetch="select">
<column name="playlist" not-null="true" unique="true" />
</many-to-one>
</class>
</hibernate-mapping>
<!-- Generated 24-set-2014 8.40.14 by Hibernate Tools 3.6.0 -->
<hibernate-mapping>
<class name="model.pojo.Playlists" table="playlists" catalog="dbname" lazy="false">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="identity" />
</id>
<set name="songsPlaylists" table="songs_playlist" inverse="true" lazy="true" fetch="select">
<key>
<column name="playlist" not-null="true" unique="true" />
</key>
<one-to-many class="model.pojo.SongsPlaylist" />
</set>
</class>
</hibernate-mapping>
the pojo classes:
public class SongsPlaylist implements java.io.Serializable {
private Integer id;
private Songs songs;
private Playlists playlists;
(...)
}
public class Songs implements java.io.Serializable {
private Integer id;
private Set songsPlaylists = new HashSet(0);
(...)
}
public class Playlists implements java.io.Serializable {
private Integer id;
private Set songsPlaylists = new HashSet(0);
(...)
}
this is my function
s = new HibernateUtil().getSessionFactory().openSession();
transaction = s.beginTransaction();
(...)
q = s.createQuery("select sp from SongsPlaylist sp where sp.playlists = :p");
q.setParameter("p", p);
sp = q.list();
//already exists a song binded to that playlist
if(sp.size()>0){
Set<Playlists> sP = sp.get(0).getPlaylists().getSongsPlaylists();
sP.add(p);
song.setSongsPlaylists(sP);
s.save(s);
}else{
//or it is in another playlist...
q = s.createQuery("select sp from SongsPlaylist sp where sp.songs = :s");
q.setParameter("s", song);
sp = q.list();
if(sp.size()>0){
Set<Songs> sP = sp.get(0).getSongs().getSongsPlaylists();
sP.add(song);
p.setSongsPlaylists(sP);
s.save(p);
}else{
s.save(new SongsPlaylist(song, p));
}
}
}
transaction.commit();
s.close();
and it stucks on the transaction.commit(); (last lines) with
org.hibernate.HibernateException: Found shared references to a collection:
model.pojo.Songs.songsPlaylists
it looks like I do something wrong when persisting a Set<Playlists (the same when I try to do that with Set<Songs>) on a persistent object. what 's the best practice for this case in order to insert a "SongPlaylist" and to avoid the hibernate exception mentioned?
