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Form parameters are not passed, but the file is processed in the same form?

I have a webform on JSP that has several string values ​​and a file uploaded to the server through a servlet. It is strange to see that I can upload the file to the server, but I can’t get the values ​​in the servlet using request.getParameter("someString") .

What is the problem with my code or manual?

EDIT: With a little research, I found out that if I use enctype="multipart/form-data" in the form tag, I cannot get the parameters into the servlet using request.getParameter() . The question may now be how can I send the file and other values ​​to the servlet for processing.

webform.jsp

 <form method="POST" enctype="multipart/form-data" action="/cassino/uploadFile" > <fieldset> <div class="form-group"> <label >*ID riparazione</label> <input type="text" name="idRiparazione" /> </div> <div class="form-group"> <label>*ID mandrino smontato</label> <input type="text" name="idMandrinoSmontato" /> </div> <div class="form-group"> <label>*Service livello(SL)</label> <input type="text" name="serviceLivello" /> </div> <div class="form-group"> <label>Attachment</label> <input type="file" name="attachment" class="" id="attach" /> </div> </fieldset> </div> <p class="text-right"> <input type="submit" value="Salva" name="newMacchina" /> <input type="reset" value="Cancella" /> </p> </form>

And uploadFile.java

 @WebServlet( name = "uploadFile", urlPatterns = { "/uploadFile" } ) public class uploadFile extends HttpServlet { private static final long serialVersionUID = 1L; private static final int THRESHOLD_SIZE = 1024 * 1024 * 3; private static final int MAX_FILE_SIZE = 1024 * 1024 * 15; private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 20; /** * handles file upload via HTTP POST method */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // checks if the request actually contains upload file //ServletFileUpload.isMultipartContent(request); String idRiparazione = request.getParameter("idRiparazione"); String idMandrinoSmontato = request.getParameter("idMandrinoSmontato"); String serviceLivello = request.getParameter("serviceLivello"); PrintWriter out = response.getWriter(); out.println("<html>"); out.println("<body>"); out.println("<h1>Hello Servlet Get</h1>"); out.println(idMandrinoSmontato); out.println(serviceLivello); out.println("</body>"); out.println("</html>"); DiskFileItemFactory factory = new DiskFileItemFactory(); factory.setSizeThreshold(THRESHOLD_SIZE); factory.setRepository(new File(System.getProperty("java.io.tmpdir"))); ServletFileUpload upload = new ServletFileUpload(factory); upload.setFileSizeMax(MAX_FILE_SIZE); upload.setSizeMax(MAX_REQUEST_SIZE); // constructs the directory path to store upload file String uploadPath = "C:\\SKFSFCassino\\uploads\\riparazione\\"; //getServletContext().getRealPath("") + File.separator + UPLOAD_DIRECTORY; // creates the directory if it does not exist File uploaddir = new File(uploadPath); if( !uploaddir.exists()) { uploaddir.mkdirs(); } try { List formItems = upload.parseRequest(request); Iterator it = formItems.iterator(); // iterates over form fields while(it.hasNext()) { FileItem item = (FileItem) it.next(); // processes only fields that are not form fields if (!item.isFormField()) { String fileName = new File(item.getName()).getName(); String filePath = uploadPath + File.separator + fileName; File storeFile = new File(filePath); // saves the file on disk item.write(storeFile); } } } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } // response.sendRedirect(request.getContextPath()+"/modules/SKFsfRepair/new/viewNewContent.jsp"); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, java.io.IOException { throw new ServletException("GET method used with " + getClass().getName() + ": POST method required."); }

I don't think there might be a display issue, but I'm a little confused by this because my web.xml does not show any mapping or servlet. However, the servlet uploaded the file and returned the following result:

 Hello Servlet Get null null
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1 answer

You are right that you can no longer use request.getParameter() in this situation using a multi-page form. FileUpload provides access to your fields without a file form through the FileItem class. When you iterate over items, check the field names for the names you are looking for.

  ... String idRiparazione = null; String idMandrinoSmontato = null; String serviceLivello = null; try { List formItems = upload.parseRequest(request); Iterator it = formItems.iterator(); // iterates over form fields while(it.hasNext()) { FileItem item = (FileItem) it.next(); // processes only fields that are not form fields if (!item.isFormField()) { String fileName = new File(item.getName()).getName(); String filePath = uploadPath + File.separator + fileName; File storeFile = new File(filePath); // saves the file on disk item.write(storeFile); } else { if ("idRiparazione".equals(item.getFieldName())) idRiparazione = item.getString(); else if ("idMandrinoSmontato".equals(item.getFieldName())) idMandrinoSmontato = item.getString(); else if ("serviceLivello".equals(item.getFieldName())) serviceLivello = item.getString(); } } PrintWriter out = response.getWriter(); out.println("<html>"); out.println("<body>"); out.println("<h1>Hello Servlet Get</h1>"); out.println(idMandrinoSmontato); out.println(serviceLivello); out.println("</body>"); out.println("</html>"); } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }
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Source: https://habr.com/ru/post/1202424/

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