一次上传多个文件时，只显示一个进度条

Question

当我一次选择多个文件（Image1和Image2）时，我只看到一个进度条如下：

我的上传小部件如下所示

 uploader = new Uploader();
 uploader.addOnFinishUploadHandler(uploadHandler);
 uploader.avoidRepeatFiles(true);
 uploader.setAutoSubmit(true);
 uploaderPanel.add(uploader);
 progressBar = new ModalUploadStatus();
 uploader.setStatusWidget(progressBar);

在服务器端，我没有使用任何自定义servlet。有什么建议吗？

我使用GWTupload 1.0.1和GWT 2.4.0

修改

上传者似乎正在将这两个文件作为一个包上传。以下是我在上传过程中收到的日志：

INFO: server response transferred  14/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  14/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:55 EDT 2015 Gwt client Uploader
INFO: server response transferred  26/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  26/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:55 EDT 2015 Gwt client Uploader
INFO: server response transferred  33/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  33/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:56 EDT 2015 Gwt client Uploader
INFO: server response transferred  44/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  44/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:56 EDT 2015 Gwt client Uploader
INFO: server response transferred  52/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  52/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:57 EDT 2015 Gwt client Uploader
INFO: server response transferred  63/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  63/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:57 EDT 2015 Gwt client Uploader
INFO: server response transferred  70/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  70/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:58 EDT 2015 Gwt client Uploader
INFO: server response transferred  81/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  81/1407 [Image1.jpg, Image2.jpg]
INFO: Mon Jun 01 10:39:58 EDT 2015 Gwt client Uploader
INFO: server response transferred  89/1407 [Image1.jpg, Image2.jpg]
INFO: server response transferred  89/1407 [Image1.jpg, Image2.jpg]
...