ajax上传文件

页面：
<form enctype = "multipart/form-data" action="http://localhost:8080/PoliceSystem/excel/importpublic" method="post" id="importingFile">
   <input type="file" name="FileUpload" id="FileUpload">
   <button type="button" id="sc">上传</button>
   <script>
      $(function(){
          $('#sc').click(function(){
              var FileUpload = new FormData(document.getElementById('importingFile'));
              $.ajax({
               type:'post',
               url:'http://localhost:8080/PoliceSystem/excel/importpublic',
               data:FileUpload,
               processData:false,
               contentType:false,
               success:function(message){
                   alert(message)
               },
               error:function(message){
                   alert(message)
               }
            })
         })
      })
   </script>
</form>
后台：

@RequestMapping(value = "/importpublic",method= RequestMethod.POST)
@ResponseBody
public AjaxResult importpublic(@RequestParam(value = "FileUpload",required = false) MultipartFile FileUpload, HttpServletRequest request, HttpServletResponse response) throws Exception {
    InputStream in = FileUpload.getInputStream();
    // 读取excel中的内容
    Map<String, Object> lineDownOrders = ExcelUtils.getBankListByExcelPublic(in);
    System.out.println(lineDownOrders);
    return success(AjaxResult.Type.SUCCESS,"导入成功",null);
}