判断是否是图片,java实现

private static boolean isImage(File file) throws IOException {
		BufferedImage bi = ImageIO.read(file);
		if(bi == null){
		   return false;
		}
		return true;

// 0.2.内容校验
public void  method(MultipartFile file){
        try {
            BufferedImage image = ImageIO.read(file.getInputStream());
            if (image == null) {
                // 图片格式不正确
                throw new RuntimeException();
            }
        } catch (IOException e) {
            throw new RuntimeException("图片格式不正确！");
        }
}