what is it went wrong? It seem correct

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 {
    @Autowired
    private SessionFactory sessionFactory;


    public List<Contact>findAll(){
       Session session = sessionFactory.openSession();
       List<Contact> contacts = session.createCriteria(Contact.class).list();
      session.close();
      return contacts;
    }
}