public class AuditInterceptor extends EmptyInterceptor {

   private SpeakeasyDomainDao<User> userDao;

   static final String DATE_CREATED_PROPERTY = "dateCreated";

   static final String CREATED_BY_PROPERTY = "createdBy";

   static final String DATE_MODIFIED_PROPERTY = "dateModified";

   static final String MODIFIED_BY_PROPERTY = "modifiedBy";

   /**
    * This class is Serializable so that it may be persisted when sessions move
    * or are 'paused' for server restarts.
    */
   private static final long serialVersionUID = 1L;
   
   /**
    * Modifies the state to add the values for the four friendly fields
    */
   @Override
   public boolean onSave(Object entity, Serializable id, Object[] state,
         String[] propertyNames, Type[] types) {

      boolean isChanged = false;

      if (entity instanceof SpeakeasyAuditedObject) {
         User currentUser = getCurrentUser();
         Date now = new Date();
         isChanged = true;
         for (int i = 0; i < propertyNames.length; i++) {
            String propertyName = propertyNames[i];
            if (propertyName.equals(DATE_CREATED_PROPERTY)) {
               state[i] = now;
            } else if (propertyName.equals(CREATED_BY_PROPERTY)) {
               state[i] = currentUser;
            } else if (propertyName.equals(DATE_MODIFIED_PROPERTY)) {
               state[i] = now;
            } else if (propertyName.equals(MODIFIED_BY_PROPERTY)) {
               state[i] = currentUser;
            }
         }
      }
      return isChanged;
   }

   /**
    * Gets the current user's id from the Acegi secureContext
    *
    * @return current user's userId
    */
   private User getCurrentUser() {

      SecureContext secureContext = SecureContextUtils.getSecureContext();
      assert secureContext != null : "no secure context available";
      Authentication auth = secureContext.getAuthentication();
      assert auth != null : "no authentication available";

      Object principal = auth.getPrincipal();
      assert principal != null : "no principal available";

      String userName = null;
      if (principal instanceof UserDetails) {
         UserDetails userDetails = (UserDetails) principal;
         userName = userDetails.getUsername();
      } else {

         userName = principal.toString();
      }

      // isn't this is going to be very slow?
      assert userName != null : "No username available";
      User exampleUser = new User();
      exampleUser.setName(userName);
      User user = userDao.get(exampleUser);
      assert user != null : "Unable to determine current user";
      return user;
   }

   public SpeakeasyDomainDao<User> getUserDao() {
      return userDao;
   }

   /**
    * Sets the userDao to use to find the User object for the current username.
    * This attribute is required.
    */
   public void setUserDao(SpeakeasyDomainDao<User> userDao) {
      this.userDao = userDao;
   }
}

public abstract class AbstractDao<T> extends HibernateDaoSupport {

(snip)

   public T get(T example) {
      return (T) getSession().createCriteria(example.getClass()).add(
            Example.create(example)).uniqueResult();
   }
}

      User exampleUser = new User();
      exampleUser.setName(userName);
      
      SessionFactory sessionFactory = userDao.getSessionFactory();
      Session session = sessionFactory.openSession();
      User user = (User) session.createCriteria(User.class).add(
            Example.create(exampleUser)).uniqueResult();
      
      //User user = userDao.get(exampleUser);
      Session currentSession = SessionFactoryUtils.getSession(sessionFactory, false);
      assert currentSession != null : "No current session";
      assert user != null : "Unable to determine current user";
      User mergedUser = (User) currentSession.merge(user);
      return mergedUser;