如何将文件 jsp 页传递给操作类

试试这个：

网页表单：

<form id="myForm" action="uploadFileData" method="post" enctype="multipart/form-data">
     Enter Your Name:
     <input type="text" name="yourname" id="yourname" /><br/>
     Select Your Photoes:
     <input type="file" name="file" id="file" />
     <input type="submit" value="save profile" />
</form>
<div id="response"></div>

在 js 中，确实喜欢：

$('form#myForm').submit(function(event){    
    //disable the default form submission
      event.preventDefault();
    //grab all form data  
      var formData = new FormData($(this)[0]);  
    $.ajax({
        url: $(this).attr('action'),
        type: "POST",      
        cache: false,
        processData: false,
        contentType: false,
        data: formData,
        success: function (res) {
              $("#response").text(res); 
        },      
        error: function(jqXHR, textStatus, errorThrown) {
                alert(textStatus+' : '+ errorThrown);
             }
      });
});

然后在 servlet 中保存文件，如下所示：

@WebServlet("/uploadFileData")
@MultipartConfig //in order to let it recognize and support multipart/form-data requests and thus get getPart() to work
public class UploadFileData extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private String UPLOAD_DIRECTORY;
    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        UPLOAD_DIRECTORY = "E:''";//request.getSession().getServletContext().getRealPath("/upload");
        // Set response content type
        response.setContentType("text/html");
        String yourname = request.getParameter("yourname");
        System.out.println(yourname);
        Part filePart = request.getPart("file");
        String fileName = getFileName(filePart);
        System.out.println("fileName:"+fileName);
        InputStream fileContent = filePart.getInputStream();
        System.out.println("upload dir: "+UPLOAD_DIRECTORY);
        File file = new File(UPLOAD_DIRECTORY+fileName);
        try{
            FileOutputStream fOutputStream = new FileOutputStream(file);
            try{
                byte[] bytes = new byte[8 * 1024];
                int bytesRead;
                while((bytesRead = fileContent.read(bytes)) != -1){
                    fOutputStream.write(bytes, 0, bytesRead);
                }
                System.out.println("file uploaded successfully..");
                response.getWriter().println("file uploaded successfully..");
            }finally{
                fOutputStream.close();
            }
        }finally{
            fileContent.close();
        }
    }
    /**
     * Utility method to extract file name from content-disposition.
     * @param filePart
     * @return file name
     */
    private String getFileName(Part filePart) {
        for(String cd: filePart.getHeader("content-disposition").split(";")){
            if(cd.trim().startsWith("filename")){
                String fileName = cd.substring(cd.indexOf('=')+1).trim().replace("'"", "");
                return fileName.substring(fileName.lastIndexOf('/') + 1).substring(fileName.lastIndexOf('''') + 1); // MSIE fix.
            }
        }
        return null;
    }
}