pom.xml
<!-- thumbnail generation library for Java -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.8</version></dependency>
package team.soi.utils;
import net.coobird.thumbnailator.Thumbnails;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
/**
* 图片工具类：<br/>
* 使用Thumbnailtor实现图片的裁剪，缩放等。<br/>
* 代码基于hoojo的工具类修改，主要是因为其代码使用了底层的API，具有平台依赖性。
*
* @author Soi 2015-10-15
* @email [email protected]
* @blog http://my.oschina.net/u/1580674
*/
public class ImageUtils {
/**
* 图像文件的格式
*/
private static final String DEFAULT_IMAGE_FORMAT = ".jpg";
/**
* 默认文件存放路径
*/
private static final String DEFAULT_FILE_PATH = "./temp-";
private static Image image = null;
private ImageUtils() {
}
/**
* 图片压缩质量枚举<br/>
* MAX-1.0f<br/>
* HIGH-0.75f<br/>
* MEDIUM-0.5f<br/>
* LOW-0.25f<br/>
*/
public enum ImageQuality {
MAX(1.0f), HIGH(0.75f), MEDIUM(0.5f), LOW(0.25f);
final Float QUALITY;
ImageQuality(Float quality) {
this.QUALITY = quality;
}
}
/**
* <b>function:</b> 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
*
* @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
* @author hoojo
* @createDate 2012-2-6 下午04:41:48
*/
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);
}
/**
* 将Image的宽度、高度缩放到指定width、height，并保存在savePath目录<br/>
*
* @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 IOException
* @author Soi
*/
public static String resize(int width, int height, String savePath, Image targetImage) throws IOException {
return resize(width, height, ImageQuality.MAX.QUALITY, savePath, targetImage);
}
/**
* <b>function:</b> 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
*
* @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 IOException
* @author hoojo
* @createDate 2012-2-7 上午11:01:27
*/
public static String resize(int width, int height, Float quality, String savePath, Image targetImage) throws 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;
}
if (quality == null || quality <= 0) {
quality = ImageQuality.MAX.QUALITY;
}
Thumbnails.of(image).size(width, height).outputQuality(quality).toFile(new File(savePath));
return savePath;
}
public static String resize(final int width, final int height, final String savePath, final String targetFile) throws IOException {
return resize(width, height, savePath, new File(targetFile));
}
public static String resize(final int width, final int height, final String savePath, final File targetFile) throws IOException {
return resize(width, height, savePath, new FileInputStream(targetFile));
}
public static String resize(final int width, final int height, final String savePath, InputStream inputStream) throws IOException {
image = ImageIO.read(inputStream);
int[] size = getSize(width, height, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 将一个网络图片文件按照指定的比例进行缩放
*
* @param scale 缩放比例
* @param savePath 保存文件路径、名称
* @param targetURL 本地图片文件
* @return 新的文件名称
* @throws IOException
* @author hoojo
* @createDate 2012-2-7 上午10:30:56
*/
public static String resize(final float scale, final String savePath, final URL targetURL) throws IOException {
image = ImageIO.read(targetURL);
int[] size = getSize(scale, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 按照固定宽度进行等比缩放本地图片
*
* @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 IOException
* @author hoojo
* @createDate 2012-2-7 上午10:49:56
*/
public static String resize(final int width, final String savePath, final File targetFile) throws IOException {
image = ImageIO.read(targetFile);
int[] size = getSize(width, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 按照固定宽度进行等比缩放网络图片
*
* @param width 固定宽度
* @param savePath 保存路径、名称
* @param targetURL 本地目标文件
* @return 返回保存路径
* @throws IOException
* @author hoojo
* @createDate 2012-2-7 上午10:50:52
*/
public static String resize(final int width, final String savePath, final URL targetURL) throws IOException {
image = ImageIO.read(targetURL);
int[] size = getSize(width, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 按照固定高度进行等比缩放本地图片
*
* @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 IOException
* @author hoojo
* @createDate 2012-2-7 上午10:51:17
*/
public static String resizeByHeight(final int height, final String savePath, final File targetFile) throws IOException {
image = ImageIO.read(targetFile);
int[] size = getSizeByHeight(height, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 按照固定高度进行等比缩放网络图片
*
* @param height 固定高度
* @param savePath 保存路径、名称
* @param targetURL 本地目标文件
* @return 返回保存路径
* @throws IOException
* @author hoojo
* @createDate 2012-2-7 上午10:52:23
*/
public static String resizeByHeight(final int height, final String savePath, final URL targetURL) throws IOException {
image = ImageIO.read(targetURL);
int[] size = getSizeByHeight(height, image);
return resize(size[0], size[1], savePath, image);
}
/**
* <b>function:</b> 通过指定大小和图片的大小，计算出图片缩小的合适大小
*
* @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
* @author hoojo
* @createDate 2012-2-6 下午05:53:10
*/
public static int[] getSize(final int width, final int height, final Image image) {
int[] target = getSize(image);
double scaling = getScaling(target[0], target[1], width, height);
long[] standard = getStandard(target, scaling);
return new int[]{Integer.parseInt(Long.toString(standard[0])), Integer.parseInt(String.valueOf(standard[1]))};
}
/**
* <b>function:</b> 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
*
* @param scale 缩放比例
* @param image 图片对象
* @return 返回宽度、高度
* @author hoojo
* @createDate 2012-2-7 上午10:27:59
*/
public static int[] getSize(final float scale, final Image image) {
int[] target = getSize(image);
long[] standard = getStandard(target, scale);
return new int[]{Integer.parseInt(Long.toString(standard[0])), Integer.parseInt(String.valueOf(standard[1]))};
}
public static int[] getSize(final int width, final Image image) {
int[] target = getSize(image);
long height = Math.round((target[1] * width) / (target[0] * 1.00f));
return new int[]{width, Integer.parseInt(String.valueOf(height))};
}
public static int[] getSizeByHeight(final int height, final Image image) {
int[] target = getSize(image);
long width = Math.round((target[0] * height) / (target[1] * 1.00f));
return new int[]{Integer.parseInt(String.valueOf(width)), height};
}
public static int[] getSize(final Image image) {
int targetWidth = image.getWidth(null);
int targetHeight = image.getHeight(null);
return new int[]{targetWidth, targetHeight};
}
public static long[] getStandard(final int[] target, final double scale) {
long standardWidth = Math.round(target[0] * scale);
long standardHeight = Math.round(target[1] * scale);
return new long[]{standardWidth, standardHeight};
}
public static void main(String[] args) throws IOException{
ImageUtils.resize(500,500,"/home/soi/xn.png","/home/soi/012133dsa4toxud8snsbo1.jpg");
}
}
