通过apache FileUpload上传没有文件的表单数据

Question

我正在使用Apache Commons FileUpload将数据上传到我的服务器 - 一些文本字段和一个文件项。有时只有没有文件的文本字段，我也需要继续这个请求。当我尝试这样做时，org.apache.commons.fileupload.FileUploadException: Stream ended unexpectedly出现在List fileItems = upload.parseRequest(request)行上。

有我的代码：

    import org.apache.commons.fileupload.FileItem;
    import org.apache.commons.fileupload.FileUploadException;
    import org.apache.commons.fileupload.disk.DiskFileItemFactory;
    import org.apache.commons.fileupload.servlet.ServletFileUpload;

    public class UploadServlet extends HttpServlet {

      private boolean isMultipart;
      private int maxFileSize = 50*1024*1024;
      private int maxMemSize = 40*1024;

      protected void processRequest(HttpServletRequest request, HttpServletResponse response)
              throws ServletException, IOException {
          ...
        try {
          ...
          isMultipart = ServletFileUpload.isMultipartContent(request);
          if(!isMultipart){
            return;
          }
          DiskFileItemFactory factory = new DiskFileItemFactory(maxMemSize,
                  new File(properties.getProperty("temp")));
          ServletFileUpload upload = new ServletFileUpload(factory);
          upload.setSizeMax(maxFileSize);
          UploadRequest uploadRequest = new UploadRequest();
          try {
            List fileItems;
            // NEXT LINE EXCEPTION
            fileItems = upload.parseRequest(request);
            Iterator i = fileItems.iterator();
            while(i.hasNext()){
              FileItem item = (FileItem)i.next();
              if(!item.isFormField()){
                String fileName = item.getName();
              }
              else {
                ...
              }
            }
...

如果我发送文件和文本字段 - 我可以阅读所有字段。如果我不发送文件 - 我也不能因为例外而阅读文本字段。任何解决方案只加载没有multipart/form-data文件的文本？