Java 文件 获取图片文件的类型

    public static void main(String[] args) {
        File f = new File("c://test.jpg");
        if (f.exists()) {
            System.out.println(getFormatInFile(f));
        }
    }

    
    private static String getFormatName(Object o) {
        try {
            ImageInputStream iis = ImageIO.createImageInputStream(o);
            Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);
            if (!iter.hasNext()) {
                return null;
            }
    
            ImageReader reader = iter.next();
            iis.close();
            return reader.getFormatName();
        } catch (IOException e) {
        }
        return null;
    }

转载于:https://www.cnblogs.com/pricks/archive/2009/11/11/1601033.html