Question

如何获取FileUpload上传文件的进度

Answer 1

file是一种特殊的input，不能被赋值，也不能被javascript取值，只能随表单提交

Answer 2

使用apache的commons-fileUpload。 1、实现进度监听接口。 public void update(long pBytesRead, long pContentLength, int pItems) { double mBytes = pBytesRead / 1000000; double total=pContentLength/1000000; if (megaBytes == mBytes) { return; } megaBytes = mBytes; if (pContentLength == -1) { System.out.println("So far, " + pBytesRead + " bytes have been read."); } else { System.out.println("So far, " + pBytesRead + " of " + pContentLength + " bytes have been read."); double read=(mBytes/total); NumberFormat nf=NumberFormat.getPercentInstance(); session.setAttribute("read", nf.format(read)); } } 2、页面通过ajax获取session中的进度： public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); HttpSession session=request.getSession(); String status=(String) session.getAttribute("read");//获取上传进度百分比 System.out.println(status+"FileUploadStatus"); out.println(status);//响应 }