java创建缩略图、伸缩图片比例生成实例

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代码如下

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package com.hoo.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
* http://hoojo.cnblogs.com
* @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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