Not sure why this is failing...

package com.teamtreehouse.contactmgr.dao;

import com.teamtreehouse.contactmgr.model.Contact;

import java.util.List;

public interface ContactDao {
  List<Contact> findAll();
}

package com.teamtreehouse.contactmgr.dao;

import com.teamtreehouse.contactmgr.model.Contact;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public class ContactDaoImpl implements ContactDao{  
  @Autowired
  private SessionFactory sessionFactory;

  @Override
  @SuppressWarnings("unchecked")
  public List<Contact> findAll(){
    Session session = sessionFactory.openSession();

    List<Contact> contact = session.createCriteria(Contact.class).list();

    session.close();   
    return null;
  }

}