title: Problem with LazyInitializationException
body: <p>I'm making an application using Hibernate 3.6.0, and I got a LazyInitializationException. I didn't manage to resolve it, so I'm here, asking for your help.</p>
  
  <p>Here is the StackTrace:</p>
  
  <pre><code>Exception in thread "AWT-EventQueue-0" org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: model.Transformator.poze, no session or session was closed
      at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383)
      at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375)
      at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:368)
      at org.hibernate.collection.PersistentSet.add(PersistentSet.java:212)
      at model.Transformator.addPoza(Transformator.java:93)
      at controller.WinController.uploadPoza(WinController.java:47)
      at view.Win$1UploadActionListener.actionPerformed(Win.java:138)
      at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
      at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
      at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
      at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
      at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
      at java.awt.Component.processMouseEvent(Unknown Source)
      at javax.swing.JComponent.processMouseEvent(Unknown Source)
      at java.awt.Component.processEvent(Unknown Source)
      at java.awt.Container.processEvent(Unknown Source)
      at java.awt.Component.dispatchEventImpl(Unknown Source)
      at java.awt.Container.dispatchEventImpl(Unknown Source)
      at java.awt.Component.dispatchEvent(Unknown Source)
      at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
      at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
      at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
      at java.awt.Container.dispatchEventImpl(Unknown Source)
      at java.awt.Window.dispatchEventImpl(Unknown Source)
      at java.awt.Component.dispatchEvent(Unknown Source)
      at java.awt.EventQueue.dispatchEvent(Unknown Source)
      at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
      at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
      at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
      at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
      at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
      at java.awt.EventDispatchThread.run(Unknown Source)
  </code></pre>
  
  <p>The saver for Transformator entity:</p>
  
  <pre><code>public void transformatorSaver(Transformator t)
      {
          Session session = SessionFactoryUtil.getInstance().getCurrentSession();
          Transaction tx = null;
  
          try
          {
              tx = session.beginTransaction();
              @SuppressWarnings("unused")
              Transformator tr = (Transformator) session.merge(t);
              tx.commit();
          }
          catch (Exception e)
          {
              tx.rollback();
          }
          finally
          {
              session.close();
          }
      }
  </code></pre>
  
  <p>The Transformator entity has a set of pictures (byte array). The exception starts when I add a new picture to the Transformator entity and call the saver for transformator.</p>
  
  <p>Which is the resolution for this poblem? Thanks</p>