java中图片文件的判断

javax.imageio 
类 ImageIO
BufferedImage bi = ImageIO.read(resFile);//resFile --- InputStreamif(bi == null){ System.out.println(此文件不为图片文件);
}try {//判断是否为图片文件并且返回图片的格式！
            ImageInputStream iis = ImageIO.createImageInputStream(o);// Find all image readers that recognize the image formatIterator<ImageReader> iter = ImageIO.getImageReaders(iis);if (!iter.hasNext()) {// No readers foundreturn null;}// Use the first readerImageReader reader = iter.next();// Close stream
            iis.close();// Return the format namereturn reader.getFormatName();
}加载一个图片：
ImageIcon(byte[] imageData, String description)