以流的方式
/**
* 获取主接线图流
* @param uri 相对路径(ftp返的路径)
*/
@GetMapping("/img")
@ResponseBody
public void getImg(@RequestParam String uri, HttpServletResponse res) throws IOException {
if (StringUtil.isBlank(uri)) {
// 非上传窗口请求
return;
}
InputStream in = uploadFileService.downloadFile(uri);
BufferedImage buffImg = ImageIO.read(in);
String imgType = uri.substring(uri.lastIndexOf(".") + 1);
res.setContentType("image/"+ imgType);
ServletOutputStream os = res.getOutputStream();
ImageIO.write(buffImg, imgType, os);
os.flush();
os.close();
in.close();
}