阿里返回圖片如何下載到本地方法

    public static String getPicture(HttpServletRequest request, String urlHttp){
        String serverPicUrl = saveFilePath+ StringUtil.qiNiuUrl(6)+".png";
        try {
            URL url = new URL(urlHttp);
            BufferedImage img = ImageIO.read(url);
            File imageFile = new File(serverPicUrl);
            File fileParent = imageFile.getParentFile();
            if(!fileParent.exists()){
                boolean mkdirs = fileParent.mkdirs();
                if(!mkdirs){
                    return "";
                }
            }
            ImageIO.write(img, "png", new File(serverPicUrl));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return serverPicUrl;
    }