关于使用uploadifive上传文件设置debug读不到第一个文件

JS代码

    $(function() {
        $('#file_upload').uploadifive({
            'auto'             : false,
            'buttonClass': 'btn btn-primary',
            'buttonText': "选择文件",
            'queueID'          : 'uploadqueue',
            'uploadScript'     : '/uploadfiles',
            'onUploadComplete' : function(file, data) { console.log(data); }
        });
    });

后台代码

 @RequestMapping("/uploadfiles")
    @ResponseBody
    public JSONArray uploadfiles(HttpServletRequest request) {
        Calendar calendar=Calendar.getInstance();
        List<String> filePathList = new ArrayList<String>();
//      String filePath= SysConstant.UPLOADPATH;
        String filePath = "C:";
//      String filePathUrl=SysConstant.UPLOADPATHURL+"/"+calendar.get(Calendar.YEAR)+calendar.get(Calendar.MONTH);
        String filePathUrl="C:/"+calendar.get(Calendar.YEAR)+calendar.get(Calendar.MONTH);

        filePath=filePath+ File.separatorChar+calendar.get(Calendar.YEAR)+calendar.get(Calendar.MONTH);
        try {
            filePathList = FileUploadUtil.uploadFile(request, filePath,filePathUrl);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch(Exception ex){
            ex.printStackTrace();
        }

        if(filePathList.size() == 0){
            //return "系统错误";
        }
        return null;
        //return JSONArray.fromObject(filePathList);

FileUploadUtil

 public class FileUploadUtil {
    private static final Logger log = LoggerFactory.getLogger(FileUploadUtil.class);

    public static List<String> uploadFile(HttpServletRequest request, String filePath, String filePathUrl) throws FileNotFoundException {

        List<String> filePathList = new ArrayList<String>();

        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;

        Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
        String fileName = null;
        for (Map.Entry<String, MultipartFile> entity : fileMap.entrySet()) {

            MultipartFile mf = entity.getValue();
            fileName = mf.getOriginalFilename();
            String newfilepath = filePath + File.separatorChar + fileName;
            //newfilepath = filePath + File.separatorChar + fileName;


            System.out.println("newfilepath=" + newfilepath);
            File dest = new File(filePath);
            if (!dest.exists()) {
                dest.mkdirs();
            }
            File uploadFile = new File(newfilepath);
            if (uploadFile.exists()) {
                uploadFile.delete();
            }
            try {

                log.info("start upload file: " + fileName);
                FileCopyUtils.copy(mf.getBytes(), uploadFile);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                // e.printStackTrace();
                log.info("upload failed. filename: " + fileName + e.getMessage());
                return null;
            }
            filePathList.add(filePathUrl+"/"+fileName);
        }

        return filePathList;
    }
}

这份代码是从网上copy过来的, 当我选择 1.txt 2.txt 后点击上传文件.
设置debug后, 其中我看到控制台先打印一句
newfilepath=C:\20177\1.txt
之后才会进入debug读取2.txt.
求解为什么同样设置debug,第一份文件就进不去呢.

$(function() {
$('#file_upload').uploadifive({
'auto' : false,
'buttonClass': 'btn btn-primary',
'buttonText': "选择文件",
'queueID' : 'uploadqueue',
'uploadScript' : '/uploadfiles',
'onUploadComplete' : function(file, data) { console.log(data); }
});
});

    这里的方法错误让人挺难受的（uploadifive）