Servlet 文件上传 ismultipartcontent 返回 false

Question

我正在尝试将选定文件从本地文件系统上传到应用程序中的文件夹。 这里用到的技术是jsp、servlet。

单击 Example.jsp 的 Press 按钮时，控制权传递给 Request servlet。 但是检查请求是否为多部分返回错误。 所以“对不起，这个 Servlet 只处理文件上传请求”会打印在控制台中。

Example.jsp

<form action="Request" method="Post" name = "invoices"  target="_self">

<div class="invoicetable">  
<table>

    <colgroup>
        <col class="first" span="1">
        <col class="rest" span="1">
    </colgroup>

    <tr>
        <td>Start date:</td>
        <td><input type = "text" name = "start_date" id="datepicker"  size = "6" maxlength="10"/></td>
    </tr>
    <tr>
        <td>End date:</td>
        <td><input type = "text" name = "end_date" id="datepicker2"  size = "6" maxlength="10"/></td>
    </tr>
    <tr>
        <form action="Request" enctype="multipart/form-data" method="post" name = "upload">
            <table>
            <tr>
                <td>Input File:</td>
                <td><input type = "file" name ="datafile" size="30" maxlength="200"/></td>
            </tr>
            </table>
            <div>
                <input type ="submit" name="invoice" value="Press"/> to upload the file!
                <input type="hidden"  name = "type" value="upload">      
            </div>

        </form>
    </tr>
    <tr>
        <td>Regular</td>
        <td>
            <input type = "radio" name ="input_type" value="regular"/>

        </td>
    </tr>
        <tr>
        <td>Manual</td>
        <td>
            <input type = "radio" name ="input_type" value="manual" checked/>

        </td>
    </tr>
        <tr>
        <td>Final</td>
        <td>
            <input type = "radio" name ="input_type" value="final"/>

        </td>
    </tr>
</table>

</div>

<div style="margin-left: 20px">
    <input type ="submit" name="invoice" value="Submit" class="button"/>
    <input type="hidden"  name = "type" value="invoice">      
</div>

</form>

请求 - doPost 方法

jsp_request = request.getParameter("type");
if (jsp_request.equalsIgnoreCase("upload")) {
            String file_location = request.getParameter("datafile");
            ServletFileUpload uploader = null;

                    //Checking if the request is multipart  
            if(ServletFileUpload.isMultipartContent(request)){


                  try {
                        String upload_location_holder = request.getServletContext().getRealPath("");
                        upload_location_holder = upload_location_holder.substring(0,upload_location_holder.indexOf(".")) + 
                        upload_location_holder.substring(upload_location_holder.lastIndexOf("/")+1);


                        //excel file goes into the input files folder
                        String excel_name = upload_location_holder + "/WebContent/input_files/" + file_location;

                        File file = new File(excel_name);

                        DiskFileItemFactory fileFactory=new DiskFileItemFactory();

                        fileFactory.setRepository(file);
                        uploader = new ServletFileUpload(fileFactory);

                        List<FileItem> fileItemsList = uploader.parseRequest(request);
                        Iterator<FileItem> fileItemsIterator = fileItemsList.iterator();

                        while (fileItemsIterator.hasNext()) {
                            FileItem item = (FileItem) fileItemsIterator.next();
                            if (!item.isFormField()) {
                                String fileName = item.getName();    
                                String root = getServletContext().getRealPath("/");
                                File path = new File(root + "/uploads");
                                if (!path.exists()) {
                                    boolean status = path.mkdirs();
                                }

                                File uploadedFile = new File(path + "/" + fileName);
                                System.out.println(uploadedFile.getAbsolutePath());
                                item.write(uploadedFile);
                            }
                        }

                       //File uploaded successfully
                       request.setAttribute("message", "File Uploaded Successfully");
                    } catch (Exception ex) {
                      // request.setAttribute("message", "File Upload Failed due to " + ex);
                       ex.printStackTrace();
                    }          

                }else{
                    System.out.println("Sorry this Servlet only handles file upload request");
                }


}

我尝试在谷歌上搜索可能的解决方案。但没有得到任何答案。 任何帮助表示赞赏。

Answer 1

亲爱的，请在您的表单标签中使用enctype="multipart/form-data"，例如：

form action="Request" method="Post" name="logout" enctype="multipart/form-data"