code: public static BufferedImage read(Object img) {
          try {
              if (img instanceof BufferedImage) {
                  return (BufferedImage) img;
              }
              if (img instanceof CharSequence) {
                  return ImageIO.read(Files.checkFile(img.toString()));
              }
              if (img instanceof File)
                  return ImageIO.read((File) img);
  
              if(img instanceof byte[])
                  return ImageIO.read(new ByteArrayInputStream((byte[])img));
  
              if (img instanceof URL)
                  img = ((URL) img).openStream();
  
              if (img instanceof InputStream) {
                  File tmp = File.createTempFile("nutz_img", ".jpg");
                  Files.write(tmp, img);
                  try {
                      return read(tmp);
                  }
                  finally {
                      tmp.delete();
                  }
              }
              throw Lang.makeThrow("Unkown img info!! --> " + img);
          }
          catch (IOException e) {
              try {
                  InputStream in = null;
                  if (img instanceof File)
                      in = new FileInputStream((File) img);
                  else if (img instanceof URL)
                      in = ((URL) img).openStream();
                  else if (img instanceof InputStream)
                      in = (InputStream) img;
                  if (in != null)
                      return readJpeg(in);
              }
              catch (IOException e2) {
                  e2.fillInStackTrace();
              }
              return null;
              // throw Lang.wrapThrow(e);
          }
      }
docs: 将一个图片文件读入内存
  
  @param img
  图片文件
  @return 图片对象