java使用ImageReader判断图片的类型，javaimagereader,package com.

java使用ImageReader判断图片的类型，javaimagereader,package com.

package com.javacodegeeks.snippets.desktop;import java.io.File;import java.io.IOException;import java.util.Iterator;import javax.imageio.ImageIO;import javax.imageio.ImageReader;import javax.imageio.stream.ImageInputStream;public class DetermineFormatOfAnImage {    public static void main(String[] args) throws IOException {        // get image format in a file        File file = new File("newimage.jpg");        // create an image input stream from the specified file        ImageInputStream iis = ImageIO.createImageInputStream(file);        // get all currently registered readers that recognize the image format        Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);        if (!iter.hasNext()) {            throw new RuntimeException("No readers found!");        }        // get the first reader        ImageReader reader = iter.next();        System.out.println("Format: " + reader.getFormatName());        // close stream        iis.close();    }}

输出：

Format: JPEG