缩放图片工具类，创建缩略图、伸缩图片比例

支持将Image的宽度、高度缩放到指定width、height，并保存在指定目录
通过目标对象的大小和标准（指定）大小计算出图片缩小的比例

可以设置图片缩放质量，并且可以根据指定的宽高缩放图片

package com.iflashbuy.util;import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;/*** function: 缩放图片工具类，创建缩略图、伸缩图片比例* @author hoojo* @createDate 2012-2-3 上午10:08:47* @file ScaleImageUtils.java* @package com.hoo.util* @blog http://blog.csdn.net/IBM_hoojo* @email hoojo_@126.com* @version 1.0*/
public abstract class ScaleImageUtils {private static final float DEFAULT_SCALE_QUALITY = 1f;private static final String DEFAULT_IMAGE_FORMAT = ".jpg"; // 图像文件的格式 private static final String DEFAULT_FILE_PATH = "C:/temp-";/*** function: 设置图片压缩质量枚举类；* Some guidelines: 0.75 high quality、0.5  medium quality、0.25 low quality* @author hoojo* @createDate 2012-2-7 上午11:31:45* @file ScaleImageUtils.java* @package com.hoo.util* @project JQueryMobile* @blog http://blog.csdn.net/IBM_hoojo* @email hoojo_@126.com* @version 1.0*/public enum ImageQuality {max(1.0f), high(0.75f), medium(0.5f), low(0.25f);private Float quality;public Float getQuality() {return this.quality;}ImageQuality(Float quality) {this.quality = quality;}}private static Image image;/*** function: 通过目标对象的大小和标准（指定）大小计算出图片缩小的比例* @author hoojo* @createDate 2012-2-6 下午04:41:48* @param targetWidth 目标的宽度* @param targetHeight 目标的高度* @param standardWidth 标准（指定）宽度* @param standardHeight 标准（指定）高度* @return 最小的合适比例*/public static double getScaling(double targetWidth, double targetHeight, double standardWidth, double standardHeight) {double widthScaling = 0d;double heightScaling = 0d;if (targetWidth > standardWidth) {widthScaling = standardWidth / (targetWidth * 1.00d);} else {widthScaling = 1d;}if (targetHeight > standardHeight) {heightScaling = standardHeight / (targetHeight * 1.00d);} else {heightScaling = 1d;}return Math.min(widthScaling, heightScaling);}/*** function: 将Image的宽度、高度缩放到指定width、height，并保存在savePath目录* @author hoojo* @createDate 2012-2-6 下午04:54:35* @param width 缩放的宽度* @param height 缩放的高度* @param savePath 保存目录* @param targetImage 即将缩放的目标图片* @return 图片保存路径、名称* @throws ImageFormatException* @throws IOException*/public static String resize(int width, int height, String savePath, Image targetImage) throws ImageFormatException, IOException {width = Math.max(width, 1);height = Math.max(height, 1);BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);image.getGraphics().drawImage(targetImage, 0, 0, width, height, null);if (savePath == null || "".equals(savePath)) {savePath = DEFAULT_FILE_PATH + System.currentTimeMillis() + DEFAULT_IMAGE_FORMAT;}FileOutputStream fos = new FileOutputStream(new File(savePath));JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos);encoder.encode(image);image.flush();fos.flush();fos.close();return savePath;}/*** function: 可以设置图片缩放质量，并且可以根据指定的宽高缩放图片* @author hoojo* @createDate 2012-2-7 上午11:01:27* @param width 缩放的宽度* @param height 缩放的高度* @param quality 图片压缩质量，最大值是1； 使用枚举值：{@link ImageQuality}* 			Some guidelines: 0.75 high quality、0.5  medium quality、0.25 low quality* @param savePath 保存目录* @param targetImage 即将缩放的目标图片* @return 图片保存路径、名称* @throws ImageFormatException* @throws IOException*/public static String resize(int width, int height, Float quality, String savePath, Image targetImage) throws ImageFormatException, IOException {width = Math.max(width, 1);height = Math.max(height, 1);BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);image.getGraphics().drawImage(targetImage, 0, 0, width, height, null);if (savePath == null || "".equals(savePath)) {savePath = DEFAULT_FILE_PATH + System.currentTimeMillis() + DEFAULT_IMAGE_FORMAT;}FileOutputStream fos = new FileOutputStream(new File(savePath));JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos);JPEGEncodeParam encodeParam = JPEGCodec.getDefaultJPEGEncodeParam(image); if (quality == null || quality <= 0) {quality = DEFAULT_SCALE_QUALITY;}/** 设置图片压缩质量 */  encodeParam.setQuality(quality, true);  encoder.encode(image, encodeParam);  image.flush();fos.flush();fos.close();return savePath;}/*** function: 通过指定大小和图片的大小，计算出图片缩小的合适大小* @author hoojo* @createDate 2012-2-6 下午05:53:10* @param width 指定的宽度* @param height 指定的高度* @param image 图片文件* @return 返回宽度、高度的int数组*/public static int[] getSize(int width, int height, Image image) {int targetWidth = image.getWidth(null);int targetHeight = image.getHeight(null);double scaling = getScaling(targetWidth, targetHeight, width, height);long standardWidth = Math.round(targetWidth * scaling);long standardHeight = Math.round(targetHeight * scaling);return new int[] { Integer.parseInt(Long.toString(standardWidth)), Integer.parseInt(String.valueOf(standardHeight)) };}/*** function: 通过指定的比例和图片对象，返回一个放大或缩小的宽度、高度* @author hoojo* @createDate 2012-2-7 上午10:27:59* @param scale 缩放比例* @param image 图片对象* @return 返回宽度、高度*/public static int[] getSize(float scale, Image image) {int targetWidth = image.getWidth(null);int targetHeight = image.getHeight(null);long standardWidth = Math.round(targetWidth * scale);long standardHeight = Math.round(targetHeight * scale);return new int[] { Integer.parseInt(Long.toString(standardWidth)), Integer.parseInt(String.valueOf(standardHeight)) };}public static int[] getSize(int width, Image image) {int targetWidth = image.getWidth(null);int targetHeight = image.getHeight(null);long height = Math.round((targetHeight * width) / (targetWidth * 1.00f));return new int[] { width, Integer.parseInt(String.valueOf(height)) };}public static int[] getSizeByHeight(int height, Image image) {int targetWidth = image.getWidth(null);int targetHeight = image.getHeight(null);long width = Math.round((targetWidth * height) / (targetHeight * 1.00f));return new int[] { Integer.parseInt(String.valueOf(width)), height };}/*** * function: 将指定的targetFile图片文件的宽度、高度大于指定width、height的图片缩小，并保存在savePath目录* @author hoojo* @createDate 2012-2-6 下午04:57:02* @param width 缩小的宽度* @param height 缩小的高度* @param savePath 保存目录* @param targetImage 改变的目标图片* @return 图片保存路径、名称* @throws ImageFormatException* @throws IOException*/public static String resize(int width, int height, String savePath, File targetFile) throws ImageFormatException, IOException {image = ImageIO.read(targetFile);int[] size = getSize(width, height, image);return resize(size[0], size[1], savePath, image);}/*** * function: 将指定的targetURL网络图片文件的宽度、高度大于指定width、height的图片缩小，并保存在savePath目录* @author hoojo* @createDate 2012-2-6 下午04:57:07* @param width 缩小的宽度* @param height 缩小的高度* @param savePath 保存目录* @param targetImage 改变的目标图片* @return 图片保存路径、名称* @throws ImageFormatException* @throws IOException*/public static String resize(int width, int height, String savePath, URL targetURL) throws ImageFormatException, IOException {image = ImageIO.read(targetURL);int[] size = getSize(width, height, image);return resize(size[0], size[1], savePath, image);}/*** function: 将一个本地的图片文件按照指定的比例进行缩放* @author hoojo* @createDate 2012-2-7 上午10:29:18* @param scale 缩放比例* @param savePath 保存文件路径、名称* @param targetFile 本地图片文件* @return 新的文件名称* @throws ImageFormatException* @throws IOException*/public static String resize(float scale, String savePath, File targetFile) throws ImageFormatException, IOException {image = ImageIO.read(targetFile);int[] size = getSize(scale, image);return resize(size[0], size[1], savePath, image);}/*** function: 将一个网络图片文件按照指定的比例进行缩放* @author hoojo* @createDate 2012-2-7 上午10:30:56* @param scale 缩放比例* @param savePath 保存文件路径、名称* @param targetFile 本地图片文件* @return 新的文件名称* @throws ImageFormatException* @throws IOException*/public static String resize(float scale, String savePath, URL targetURL) throws ImageFormatException, IOException {image = ImageIO.read(targetURL);int[] size = getSize(scale, image);return resize(size[0], size[1], savePath, image);}/*** function: 按照固定宽度进行等比缩放本地图片* @author hoojo* @createDate 2012-2-7 上午10:49:56* @param width 固定宽度* @param savePath 保存路径、名称* @param targetFile 本地目标文件* @return 返回保存路径* @throws ImageFormatException* @throws IOException*/public static String resize(int width, String savePath, File targetFile) throws ImageFormatException, IOException {image = ImageIO.read(targetFile);int[] size = getSize(width, image);return resize(size[0], size[1], savePath, image);}/*** function: 按照固定宽度进行等比缩放网络图片* @author hoojo* @createDate 2012-2-7 上午10:50:52* @param width 固定宽度* @param savePath 保存路径、名称* @param targetFile 本地目标文件* @return 返回保存路径* @throws ImageFormatException* @throws IOException*/public static String resize(int width, String savePath, URL targetURL) throws ImageFormatException, IOException {image = ImageIO.read(targetURL);int[] size = getSize(width, image);return resize(size[0], size[1], savePath, image);}/*** * function: 按照固定高度进行等比缩放本地图片* @author hoojo* @createDate 2012-2-7 上午10:51:17* @param height 固定高度* @param savePath 保存路径、名称* @param targetFile 本地目标文件* @return 返回保存路径* @throws ImageFormatException* @throws IOException*/public static String resizeByHeight(int height, String savePath, File targetFile) throws ImageFormatException, IOException {image = ImageIO.read(targetFile);int[] size = getSizeByHeight(height, image);return resize(size[0], size[1], savePath, image);}/*** function: 按照固定高度进行等比缩放网络图片* @author hoojo* @createDate 2012-2-7 上午10:52:23* @param height 固定高度* @param savePath 保存路径、名称* @param targetFile 本地目标文件* @return 返回保存路径* @throws ImageFormatException* @throws IOException*/public static String resizeByHeight(int height, String savePath, URL targetURL) throws ImageFormatException, IOException {image = ImageIO.read(targetURL);int[] size = getSizeByHeight(height, image);return resize(size[0], size[1], savePath, image);}/*** function:* @author hoojo* @createDate 2012-2-3 上午10:08:47* @param args* @throws IOException * @throws MalformedURLException * @throws ImageFormatException */public static void main(String[] args) throws ImageFormatException, MalformedURLException, IOException {System.out.println(ScaleImageUtils.resize(140, 140, null, new URL("http://www.open-open.com/lib/images/logo.jpg")));ScaleImageUtils.resize(100, 100, ImageQuality.high.getQuality(), null, ImageIO.read(new URL("http://www.open-open.com/lib/images/logo.jpg")));}
}

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