Question

我在JSP上有一个webform，它有几个字符串值和一个通过servlet上传到服务器的文件。很奇怪我能够将文件上传到服务器但无法使用request.getParameter("someString")获取servlet中的值。

我的代码有什么问题，或指导我？

修改通过一些研究，我已经知道如果我在表单标记中使用enctype="multipart/form-data"，我将无法使用request.getParameter()在servlet中获取参数。问题可能是现在，如何将文件和其他值发送到servlet进行处理。

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>

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's 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.");
    }

我不认为映射可能存在问题，但我对此也有些困惑，因为我的web.xml没有显示任何映射或servlet。但是，servlet将上载文件并返回以下输出：

Hello Servlet Get

null null

Answer 1

在这种情况下，使用多部分表单时，您无法再使用request.getParameter()，这是正确的。 FileUpload可通过FileItem课程访问您的非文件表单字段。在迭代项目时，请根据您要查找的名称检查字段名称。

    ...
    String idRiparazione = null;
    String idMandrinoSmontato = null;
    String serviceLivello = null;

    try {
        List formItems = upload.parseRequest(request);
        Iterator it = formItems.iterator();
        // iterates over form's 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();
    }

表单参数未传递但处理相同表单的文件？

1 个答案: