Dúvida Spring+JPA

public void relatorio(){
		try {
			Categoria c = categoriaDAO.findById(new Long(2));
			 session = categoriaDAO.criaSession();
			if(!(session.isOpen())){
				session = (Session)categoriaDAO.getEntityManager().getDelegate();
			}
			
			session.update(c);
			session.close();
			
		}catch(Exception e){
			e.printStackTrace();
		}
	}

@Override
	@Transactional(propagation=Propagation.REQUIRED,readOnly=false)
	public  Session criaSession() {
		return  (Session)getEntityManager().getDelegate();
	}

[code]

Exception:

Session is closed!