...
@Id
@GeneratedValue(generator = "channel-id")
@GenericGenerator(name = "channel-id", strategy = "increment")
public Long getId() {
   return id;
}
...
@ManyToOne
@JoinColumn(name = "parent")
public Channel getParent() {
   return parent;
}
...
@OneToMany(mappedBy = "parent")
public Set<Channel> getSubchannels() {
   return subchannels;
}
...

@Before
public void setUp() throws Exception {
   Channel c = new Channel();
   c.setName(CHNAME);
   this.channelDao.create(c);
   
   Channel subc = new Channel();
   subc.setName(SUBCHNAME);
   subc.setParent(c);
   this.channelDao.create(subc);
      
   c = new Channel();
   c.setName(SUBCHNAME + 2);
   c.setParent(subc);
   this.channelDao.create(c);

        c = new Channel();
   c.setName(CHNAME + 2);
   this.channelDao.create(c);
}

public void testGetById() {
   Channel c = this.channelDao.getById(1L);
   assertNotNull(c);
   assertEquals(CHNAME, c.getName());
   assertNull(c.getParent());
   c.getSubchannels();
-->   assertEquals(1, c.getSubchannels().size());
      
   c = this.channelDao.getById(3L);
   assertNotNull(c);
   assertEquals(SUBCHNAME + 2, c.getName());
   assertNotNull(c.getParent());
   assertEquals(2, (long)c.getParent().getId());
}

Second pass for collection: com.wochs.api.timeframe.model.Channel.subchannels
DEBUG CollectionBinder - Binding a OneToMany: com.wochs.api.timeframe.model.Channel.subchannels through a foreign key
INFO  CollectionBinder - Mapping collection: com.wochs.api.timeframe.model.Channel.subchannels -> channel
DEBUG TableBinder - Retrieving property com.wochs.api.timeframe.model.Channel.parent
DEBUG CollectionSecondPass - Mapped collection key: parent, one-to-many: com.wochs.api.timeframe.model.Channel

@Test
@Transactional
@Rollback(false)
public void testGetById() {
   setUp();  <-- create entries manually
   Channel c = this.channelDao.getById(1L);
   assertNotNull(c);
   assertEquals(CHNAME, c.getName());
   assertNull(c.getParent());
   
   c = this.channelDao.getById(3L);
   assertNotNull(c);
   assertEquals(SUBCHNAME + 2, c.getName());
   assertNotNull(c.getParent());
   assertEquals(2, (long)c.getParent().getId());
}

@Test
public void testGetById2() {
   Channel c = this.channelDao.getById(1L);
   assertNotNull(c);
   assertEquals(1, c.getSubchannels().size());
      
   Channel sub = c.getSubchannels().iterator().next();
   assertNotNull(sub);
   assertEquals(1, sub.getSubchannels().size());
   assertEquals(SUBCHNAME, sub.getName());
   assertEquals(1, (long) sub.getParent().getId());
}

@Override
public void create(Channel c) throws DataAccessException {
   Assert.notNull(c, "channel cannot be null");
   
   try {
      getSessionFactory().getCurrentSession().save(c);
   } catch (HibernateException ex) {
      throw convertHibernateAccessException(ex);
   }
}

@Override
public Channel getById(Long id) throws DataAccessException {
   Assert.notNull(id);
   
   try {
      return (Channel) getSession().get(Channel.class, id);
   }catch(HibernateException ex) {
      throw convertHibernateAccessException(ex);
   }
}