<dependency>

            <groupId>commons-io</groupId>

            <artifactId>commons-io</artifactId>

            <version>2.8.0</version>

        </dependency>

import org.apache.commons.io.FileUtils;

import javax.imageio.ImageIO;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

/**

 * @author

 * @date 2021/10/11

 */

public class ImageScaleUtils {

    /**

     * 缩小图片

     *

     * @param srcFile 原图片

     * @param destFile 目标图片

     * @param boxWidth  缩略图最大宽度

     * @param boxHeight 缩略图最大高度

     * @throws IOException

     */

    public static void resizeFix(File srcFile, File destFile, int boxWidth,

                                 int boxHeight) throws IOException {

        BufferedImage srcImgBuff = ImageIO.read(srcFile);

        int width = srcImgBuff.getWidth();

        int height = srcImgBuff.getHeight();

        if (width <= boxWidth && height <= boxHeight) {

            FileUtils.copyFile(srcFile, destFile);

            return;

        }

        int zoomWidth;

        int zoomHeight;

        if ((float) width / height > (float) boxWidth / boxHeight) {

            zoomWidth = boxWidth;

            zoomHeight = Math.round((float) boxWidth * height / width);

        } else {

            zoomWidth = Math.round((float) boxHeight * width / height);

            zoomHeight = boxHeight;

        }

        BufferedImage imgBuff = scaleImage(srcImgBuff, width, height,

                zoomWidth, zoomHeight);

        writeFile(imgBuff, destFile);

    }

    /**

     * 裁剪并压缩

     *

     * @param srcFile 原文件

     * @param destFile 目标文件

     * @param boxWidth 缩略图最大宽度

     * @param boxHeight 缩略图最大高度

     * @param cutTop 裁剪TOP

     * @param cutLeft 裁剪LEFT

     * @param cutWidth  裁剪宽度

     * @param catHeight  裁剪高度

     * @throws IOException

     */

    public static void resizeFix(File srcFile, File destFile, int boxWidth,

                                 int boxHeight, int cutTop, int cutLeft, int cutWidth, int catHeight)

            throws IOException {

        BufferedImage srcImgBuff = ImageIO.read(srcFile);

        srcImgBuff = srcImgBuff.getSubimage(cutTop, cutLeft, cutWidth,

                catHeight);

        int width = srcImgBuff.getWidth();

        int height = srcImgBuff.getHeight();

        if (width <= boxWidth && height <= boxHeight) {

            writeFile(srcImgBuff, destFile);

            return;

        }

        int zoomWidth;

        int zoomHeight;

        if ((float) width / height > (float) boxWidth / boxHeight) {

            zoomWidth = boxWidth;

            zoomHeight = Math.round((float) boxWidth * height / width);

        } else {

            zoomWidth = Math.round((float) boxHeight * width / height);

            zoomHeight = boxHeight;

        }

        BufferedImage imgBuff = scaleImage(srcImgBuff, width, height,

                zoomWidth, zoomHeight);

        writeFile(imgBuff, destFile);

    }

    public static void writeFile(BufferedImage imgBuf, File destFile)

            throws IOException {

        File parent = destFile.getParentFile();

        if (!parent.exists()) {

            parent.mkdirs();

        }

        ImageIO.write(imgBuf, "jpeg", destFile);

    }

    private static BufferedImage scaleImage(BufferedImage srcImgBuff,

                                            int width, int height, int zoomWidth, int zoomHeight) {

        int[] colorArray = srcImgBuff.getRGB(0, 0, width, height, null, 0,

                width);

        BufferedImage outBuff = new BufferedImage(zoomWidth, zoomHeight,

                BufferedImage.TYPE_INT_RGB);

        // 宽缩小的倍数

        float wScale = (float) width / zoomWidth;

        int wScaleInt = (int) (wScale + 0.5);

        // 高缩小的倍数

        float hScale = (float) height / zoomHeight;

        int hScaleInt = (int) (hScale + 0.5);

        int area = wScaleInt * hScaleInt;

        int x0, x1, y0, y1;

        int color;

        long red, green, blue;

        int x, y, i, j;

        for (y = 0; y < zoomHeight; y++) {

            // 得到原图高的Y坐标

            y0 = (int) (y * hScale);

            y1 = y0 + hScaleInt;

            for (x = 0; x < zoomWidth; x++) {

                x0 = (int) (x * wScale);

                x1 = x0 + wScaleInt;

                red = green = blue = 0;

                for (i = x0; i < x1; i++) {

                    for (j = y0; j < y1; j++) {

                        color = colorArray[width * j + i];

                        red += getRedValue(color);

                        green += getGreenValue(color);

                        blue += getBlueValue(color);

                    }

                }

                outBuff.setRGB(x, y, comRGB((int) (red / area),

                        (int) (green / area), (int) (blue / area)));

            }

        }

        return outBuff;

    }

    private static int getRedValue(int rgbValue) {

        return (rgbValue & 0x00ff0000) >> 16;

    }

    private static int getGreenValue(int rgbValue) {

        return (rgbValue & 0x0000ff00) >> 8;

    }

    private static int getBlueValue(int rgbValue) {

        return rgbValue & 0x000000ff;

    }

    private static int comRGB(int redValue, int greenValue, int blueValue) {

        return (redValue << 16) + (greenValue << 8) + blueValue;

    }

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

        resizeFix(

                new File("C:\\Users\\Public\\Pictures\\Sample Pictures\\Chrysanthemum.jpg"), new File(

                        "C:\\Users\\Public\\Pictures\\Sample Pictures\\Chrysanthemum-1.jpg"), 310, 310);

        resizeFix(

                new File("C:\\Users\\Public\\Pictures\\Sample Pictures\\Chrysanthemum.jpg"), new File(

                        "C:\\Users\\Public\\Pictures\\Sample Pictures\\Chrysanthemum-2.jpg"), 310, 310,140,200,300,400);

    }

}