[JAVA] Simultaneous upload of image saving and linking

When saving while linking images and text

CreateServlet

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String _token = getParamVal(request.getPart("_token")); // = (String) request.getParameter("_token");

        if (_token != null && _token.equals(request.getSession().getId())) {
            EntityManager em = DBUtil.createEntityManager();

            Reshipi r = new Reshipi(); 
            Picture p = new Picture(); 

            String name = getParamVal(request.getPart("name")); // = request.getParameter("name");　
            r.setName(name);　

            String content = getParamVal(request.getPart("content")); // = request.getParameter("content");
            r.setContent(content);

            Timestamp currentTime = new Timestamp(System.currentTimeMillis());
            r.setCreated_at(currentTime);
            r.setUpdated_at(currentTime);

            //Get name
            String file_name = getParamVal(request.getPart("file_name")); 
            p.setFile_name(file_name);
            //Get the recipe ID
            Reshipi reshipi_id = getParamVal(request.getPart("reshipi_id"));
            p.setReshipi_id(reshipi_id);
            //Get the id of the picture
            Integer id = getParmVal(request.getPart("id"));
            p.setId(id);
            //Creating an error list
            List<String> errors = ReshipiValidator.validate(r);
            //If there is an error
            if (errors.size() > 0) {
                //Close DB
                em.close();
                
                request.setAttribute("_token", request.getSession().getId());
                request.setAttribute("content", r);
                request.setAttribute("errors", errors);

                response.sendRedirect(request.getContextPath() + "/index");
                return;
            } else {
                //Save to database
                em.getTransaction().begin();
                em.persist(r);
                em.getTransaction().commit();
                request.getSession().setAttribute("flush", "Registration has been completed");
                em.close();
            }
            //Image processing received from the image form
            request.setCharacterEncoding("UTF-8");
            response.setContentType("text/html; charset=UTF-8");
            Collection<Part> parts = request.getParts();

            for (Part part : parts) {
                String f_name = getFileName(part);
                if(!f_name.contains("no_p_name") && !f_name.isEmpty()){

                part.write(getServletContext().getRealPath("/images") + "/" + f_name);
                response.getWriter().append("upload:").append(f_name);
                }

            }

I wrote, but in reality

CreateServlet

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String _token = getParamVal(request.getPart("_token")); // = (String) request.getParameter("_token");

        if (_token != null && _token.equals(request.getSession().getId())) {
            EntityManager em = DBUtil.createEntityManager();

            Reshipi r = new Reshipi();
            Picture p = new Picture();

            String name = getParamVal(request.getPart("name")); // = request.getParameter("name");
            r.setName(name);

            String content = getParamVal(request.getPart("content")); // = request.getParameter("content");
            r.setContent(content);

            Timestamp currentTime = new Timestamp(System.currentTimeMillis());
            r.setCreated_at(currentTime);
            r.setUpdated_at(currentTime);

            String file_name = getParamVal(request.getPart("file_name"));
            p.setFile_name(file_name);

            //Image and reshipi_Linking with id ★★★★★★★★★★★★★
            p.setReshipi_id(r);

            //Image processing received from the image form ↓ ★★★★★★★★★★★★★★★
            //In the code above, it was at the bottom, but it does not work properly even under the save process etc.
            //It works only when it is on the code to save to DB
            request.setCharacterEncoding("UTF-8");
            response.setContentType("text/html; charset=UTF-8");
            Collection<Part> parts = request.getParts();

            for (Part part : parts) {
                String f_name = getFileName(part);
                if(!f_name.contains("no_p_name") && !f_name.isEmpty()){

                part.write(getServletContext().getRealPath("/images") + "/" + f_name);
                response.getWriter().append("upload:").append(f_name);
                p.setFile_name(f_name);
                }
            }
            List<String> errors = ReshipiValidator.validate(r);
            if (errors.size() > 0) {
                em.close();

                request.setAttribute("_token", request.getSession().getId());
                request.setAttribute("content", r);
                request.setAttribute("errors", errors);

                response.sendRedirect(request.getContextPath() + "/index");
                return;
            } else {
                //Save process
                em.getTransaction().begin();
                em.persist(r);
                //Insert image saving process ★★★★★★★★★★★★★★★★★★★★★
                em.persist(p);
                em.getTransaction().commit();
                request.getSession().setAttribute("flush", "Registration has been completed");
                em.close();
            }

Will be.