anchor.diff:              <td>文件大小</td>
               <td>操作</td>
           </tr>
  +        <c:set var = "noFileFlag" value="true"/>
           <c:forEach items="${fileListByHoid }" var="filelist">
  -            <tr <c:if test="${filelist.uptime==null}">class='danger'</c:if>>
  +            <tr
  +                    <c:if test="${filelist.uptime==null}">
  +                        class='danger'
  +                    </c:if>
  +<%--                    if there is file uploaded, make flag to be false;--%>
  +                    <c:if test="${filelist.uptime!=null}">
  +                        <c:set var = "noFileFlag" value="false"/>
  +                    </c:if>>
                   <td><p>${filelist.osubject }</p></td>
                   <td><p>${filelist.oname }</p></td>
                   <td><p>${filelist.uptime==null?"未上传":"已上传" }</p></td>
  
positive.code:     }
  
      function downall() {
          window.open("${basePath }downAllFile", "_blank");
      }
  
      function view(hid) {
  
negative.code:     String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
      application.setAttribute("basePath", basePath);
  %>
  <button type="button" class="btn btn-success" style="margin-bottom: 10px;" onclick="downall()">下载全部本科目作业</button>
  <span id="total"></span>
  <div class="table-responsive">
      <table class="table table-hover">
  