Java小技巧-JDK21从链接下载图片并返回byte数组

JDK21从链接下载图片并返回byte数组

获得URL

private static URL getUrl(String url) {
  URI uri = URI.create(url);
  URL url;
  try {
    url = uri.toURL();
  } catch(Exception e) {
  }
  return url;
}

下载

public static byte[] getByteDataByUrl(String dataUrl) {

        byte[] respData = null;
        //尝试与互联网取得连接
        try (
                //用字节流的形式来下载
                InputStream inputStream = getUrl(dataUrl).openConnection().getInputStream();
                ByteArrayOutputStream outputStream = new ByteArrayOutputStream()
        ) {
            //操作流
            byte[] buffer = new byte[1024];
            int length = 0;
            while ((length = inputStream.read(buffer)) != -1) {
                //从buffer数组off位置写length长度的字节到buffer数组中
                outputStream.write(buffer, 0, length);
            }
            respData = outputStream.toByteArray();
            return respData;
        } catch (IOException e) {
            log.error("从链接:{},中获取字节信息失败,错误信息: {}", dataUrl, e.getMessage());
            return respData;
        }
    }