java中ImageReader和BufferedImage获取图片尺寸实例

ImageReader 对象通常由特定格式的服务提供者接口 (SPI) 类实例化。服务提供者类（例如 ImageReaderSpi 的实例）向 IIORegistry 注册，后者使用前者进行格式识别和表示可用格式 reader 和 writer。

BufferedImage子类描述具有可访问图像数据缓冲区的Image。BufferedImage由图像数据的ColorModel和Raster组成。Raster的SampleModel中band的数量和类型必须与ColorModel所要求的数量和类型相匹配，以表示其颜色和alpha分量。所有BufferedImage对象的左上角坐标都为(0,0)。因此，用来构造BufferedImage的任何Raster都必须满足：minX=0且minY=0。

多的不用说，上代码，大家伙儿看看

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									/**

									 * 

									 */

									package com.b510;

									import java.awt.image.BufferedImage;

									import java.io.File;

									import java.io.FileInputStream;

									import java.io.FileNotFoundException;

									import java.io.IOException;

									import java.util.Date;

									import java.util.Iterator;

									import javax.imageio.ImageIO;

									import javax.imageio.ImageReader;

									import javax.imageio.stream.ImageInputStream;

									public class ImageUtil {

									    /**

									   * 源图片路径名称如:c:/1.jpg

									   */

									    private String srcpath = "e:/pool.jpg";

									    public ImageUtil() {

									    }

									    public static void main(String[] args) throws Exception {

									        ImageUtil util = new ImageUtil();

									        util.getImageSizeByImageReader(util.getSrcpath());

									        util.getImageSizeByBufferedImage(util.getSrcpath());

									    }

									    /**

									   * 使用ImageReader获取图片尺寸

									   * 

									   * @param src

									   *      源图片路径

									   */

									    public void getImageSizeByImageReader(String src) {

									        long beginTime = new Date().getTime();

									        File file = new File(src);

									        try {

									            Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName("jpg");

									            ImageReader reader = (ImageReader) readers.next();

									            ImageInputStream iis = ImageIO.createImageInputStream(file);

									            reader.setInput(iis, true);

									            System.out.println("width:" + reader.getWidth(0));

									            System.out.println("height:" + reader.getHeight(0));

									        }

									        catch (IOException e) {

									            e.printStackTrace();

									        }

									        long endTime = new Date().getTime();

									        System.out.println("使用[ImageReader]获取图片尺寸耗时：[" + (endTime - beginTime)+"]ms");

									    }

									    /**

									   * 使用BufferedImage获取图片尺寸

									   * 

									   * @param src

									   *      源图片路径

									   */

									    public void getImageSizeByBufferedImage(String src) {

									        long beginTime = new Date().getTime();

									        File file = new File(src);

									        FileInputStream is = null;

									        try {

									            is = new FileInputStream(file);

									        }

									        catch (FileNotFoundException e2) {

									            e2.printStackTrace();

									        }

									        BufferedImage sourceImg = null;

									        try {

									            sourceImg = javax.imageio.ImageIO.read(is);

									            System.out.println("width:" + sourceImg.getWidth());

									            System.out.println("height:" + sourceImg.getHeight());

									        }

									        catch (IOException e1) {

									            e1.printStackTrace();

									        }

									        long endTime = new Date().getTime();

									        System.out.println("使用[BufferedImage]获取图片尺寸耗时：[" + (endTime - beginTime)+"]ms");

									    }

									    public String getSrcpath() {

									        return srcpath;

									    }

									    public void setSrcpath(String srcpath) {

									        this.srcpath = srcpath;

									    }

									}