commons-fileupload文件上传，支持多文件

FileItemFactory fileItemFactory = new DiskFileItemFactory();
ServletFileUpload servletFileUpload = new ServletFileUpload(fileItemFactory);
List<FileItem> list = servletFileUpload.parseRequest(request);
String destDir = request.getServletContext().getRealPath("/") + Constant.FILE_PATH;
File uploadFile;
for (FileItem fileItem : list) {
if(!fileItem.isFormField()){
uploadFile = new File(destDir + fileItem.getName());
fileItem.write(uploadFile);
System.out.println(uploadFile.getAbsolutePath());
}
}

spring中使用不需要配置<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="utf-8"/>

代码量跟spring提供的上传差不多，只是觉得这个更好，完全不依赖于spring，只是多了FileItemFactory那几步。