Hibernate: could not initialize proxy - no Session

package com.netcraft.controller;
 
import com.netcraft.model.Attribute;
import com.netcraft.model.HObject;
import com.netcraft.hibernate.Attribute.service.AttributeService;
import com.netcraft.hibernate.HObject.service.ObjectService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
 
import java.sql.SQLException;
 
@Controller
public class TestController {
 
    @Autowired
    private AttributeService attributeService;
 
    @Autowired
    private ObjectService objectService;
 
    @ModelAttribute
    public void addingCommonObjects(Model model1){
        model1.addAttribute("headerMsg", "Hello I am Header!");
    }
 
 
    @RequestMapping(value = "/test")
    public ModelAndView test() throws SQLException {
        ModelAndView modelAndView = new ModelAndView("testpage");
 
        System.out.println("[TestController] objectService = " + objectService);
        System.out.println("[TestController] attributeService = " + attributeService);
 
        HObject object = objectService.getObject(1);
        Attribute attribute = attributeService.getAttribute(1);
 
        System.out.println("[TestController] object = " + object.getName());
        System.out.println("[TestController] attribute = " + attribute.getName());
 
        modelAndView.addObject("object", object);
        modelAndView.addObject("attribute", attribute);
 
        return modelAndView;
    }
}

package com.netcraft.hibernate.Attribute.DAO;
 
import com.netcraft.model.Attribute;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
 
import java.sql.SQLException;
 
@Repository
public class AttributeDAOImpl implements AttributeDAO {
 
    @Autowired
    SessionFactory sessionFactory;
 
    @Override
    public void addAttribute(Attribute attribute) throws SQLException {
        sessionFactory.getCurrentSession().save(attribute);
    }
 
    @Override
    public void updateAttribute(Attribute attribute) throws SQLException {
        sessionFactory.getCurrentSession().update(attribute);
    }
 
    @Override
    public Attribute getAttribute(long attr_id) throws SQLException {
        return (Attribute)sessionFactory.getCurrentSession().load(Attribute.class, attr_id);
    }
 
    @Override
    public void deleteAttribute(Attribute attribute) throws SQLException {
        sessionFactory.getCurrentSession().delete(attribute);
    }
}

package com.netcraft.util.hibernate.Attribute;
 
import com.netcraft.model.Attribute;
import com.netcraft.util.hibernate.HibernateUtil;
import org.hibernate.Session;
 
import java.sql.SQLException;
 
public class AttributeDAOImpl implements AttributeDAO {
 
    @Override
    public void addAttribute(Attribute attribute) throws SQLException {
        Session session = null;
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            session.beginTransaction();
            session.save(attribute);
            session.getTransaction().commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
    }
 
    @Override
    public void updateAttribute(Attribute attribute) throws SQLException {
        Session session = null;
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            session.beginTransaction();
            session.update(attribute);
            session.getTransaction().commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
    }
 
    @Override
    public Attribute getAttribute(long attr_id) throws SQLException {
        Session session = null;
        Attribute attribute = null;
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            attribute = (Attribute) session.load(Attribute.class, attr_id);
            System.out.println("[AttributeDAOImpl] attribute = " + attribute.getName());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
        return attribute;
    }
 
    @Override
    public void deleteAttribute(Attribute attribute) throws SQLException {
        Session session = null;
        try {
            session = HibernateUtil.getSessionFactory().openSession();
            session.beginTransaction();
            session.delete(attribute);
            session.getTransaction().commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
    }
}