图片压缩工具类

依赖

<dependency>
   <groupId>cn.hutool</groupId>
   <artifactId>hutool-all</artifactId>
   <version>5.8.24</version>
</dependency>

代码

package com.zhanghuan.material.utils;

import cn.hutool.core.io.FileUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;


@Slf4j
public class ImageCompressUtils {

    public static File compressImage(MultipartFile file, String targetDir, long maxSize) throws IOException {

        String extName = FileUtil.extName(file.getOriginalFilename());

        // 确保目标路径存在
        FileUtil.mkdir(targetDir);

        // 临时文件路径
        String tempPath = targetDir + File.separator + file.getName();
        File tempFile = new File(tempPath);
        file.transferTo(tempFile);

        // 压缩图片
        long size = FileUtil.size(tempFile);
        int num = 0;
        float rate = 0.9f;
        while (size > maxSize && num <20) {
            compress(tempPath,extName,rate);
            size = FileUtil.size(tempFile);
            num++;
            rate *= rate;
        }
        log.info("当前图片{}压缩次数：{}",tempPath,num);

        return tempFile;
    }

    public static File compressImage(File file, long maxSize) throws IOException {

        String extName = FileUtil.extName(file.getName());

        // 压缩图片
        long size = FileUtil.size(file);
        int num = 0;
        float rate = 0.9f;
        while (size > maxSize && num <20) {
            compress(file.getAbsolutePath(),extName,rate);
            size = FileUtil.size(file);
            num++;
            rate *= rate;
        }
        log.info("当前图片{}压缩次数：{}",file,num);

        return file;
    }

    public static boolean isImage(File file) {
        String extension = FileUtil.getSuffix(file.getName());
        String[] imageExtensions = new String[]{"jpg", "jpeg", "png", "gif", "bmp", "webp"};
        for (String imgExtension : imageExtensions) {
            if (imgExtension.equalsIgnoreCase(extension)) {
                return true;
            }
        }
        return false;
    }

    public static boolean isImage(String filename) {
        String extension = FileUtil.getSuffix(filename);
        String[] imageExtensions = new String[]{"jpg", "jpeg", "png", "gif", "bmp", "webp"};
        for (String imgExtension : imageExtensions) {
            if (imgExtension.equalsIgnoreCase(extension)) {
                return true;
            }
        }
        return false;
    }


    private static void compress(String fileFullPathName,String formatName,float rate) throws IOException {
        File file = new File(fileFullPathName);
        BufferedImage originalImage = ImageIO.read(file);

        // 设置压缩后的最大宽度和高度（单位为像素）
        int maxWidth = (int) (1600 * rate);
        int maxHeight = (int) (1600 * rate);

        int width = originalImage.getWidth();
        int height = originalImage.getHeight();

        // 计算压缩比例
        double scaleX = (double)maxWidth / width;
        double scaleY = (double)maxHeight / height;
        double scaleFactor = Math.min(scaleX, scaleY);

        // 创建新的BufferedImage对象，指定压缩后的尺寸
        int newWidth = (int)(width * scaleFactor);
        int newHeight = (int)(height * scaleFactor);


        BufferedImage compImage = new BufferedImage(newWidth, newHeight, originalImage.getType());
        Graphics2D g = compImage.createGraphics();
        g.drawImage(originalImage, 0, 0, newWidth, newHeight, null);
        g.dispose();

        //将压缩后的图片保存到文件
        ImageIO.write(compImage, formatName, new File(fileFullPathName));
    }

    public static void main(String[] args) {
        String path = "C:\\Users\\Administrator\\Desktop\\test\\img\\7775EF761C1CD6CE8A0C2CA280E8321C.png";
        try {
            compressImage(new File(path),500*1024);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}