@Override
public void readData(HttpServletRequest request, ModelMap params,
String charset) {
// 构建带上传进度监视的文件工厂
MonitoredDiskFileItemFactory factory = new MonitoredDiskFileItemFactory(
new UploadListener(request));
// 初始化上传参数
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(this.fileSizeMax);
upload.setSizeMax(this.sizeMax);