Ftp ftp = site.getUploadFtp();
String ftpUrl = ftp.getUrl();
if (!StringUtils.isBlank(filename)
&& FilenameUtils.getExtension(filename).equals(ext)) {
filename = filename.substring(ftpUrl.length());
fileUrl = ftp.storeByFilename(filename, file
.getInputStream());
} else {
fileUrl = ftp.storeByExt(site.getUploadPath(), ext, file
.getInputStream());
// 加上url前缀