java实现office办公软件(word、pdf、excel、ppt) 及 视频文件 生成缩略图

最近工作需要，要生成office文档的缩略图，调研下来有几个还不错的组件：

1. aspose 这个有收费版和免费版，免费版转换篇幅有限制且生成和转化有水印
2. spire 这个是本篇博文使用的组件，同样有收费版和免费版，免费版转换有篇幅限制但是没有水印
3. libreoffice 这个需要依赖于外部应用，需要把服务部署在所在服务器使用

接下来介绍一下spire的生成office文档和视频文件（使用ffmpeg）缩略图的方法

1. maven依赖：

    <repositories>
        <repository>
            <id>com.e-iceblue</id>
            <url>https://repo.e-iceblue.cn/repository/maven-public/</url>
        </repository>
    </repositories>

    <dependency>
        <groupId>org.bytedeco</groupId>
        <artifactId>javacv</artifactId>
        <version>1.4.3</version>
    </dependency>
    <dependency>
        <groupId>org.bytedeco.javacpp-presets</groupId>
        <artifactId>ffmpeg-platform</artifactId>
        <version>4.0.2-1.4.3</version>
    </dependency>
    <dependency>
        <groupId>e-iceblue</groupId>
        <artifactId>spire.office.free</artifactId>
        <version>5.3.1</version>
    </dependency>

2. 工具类

import com.spire.doc.Document;
import com.spire.doc.documents.ImageType;
import com.spire.pdf.PdfDocument;
import com.spire.pdf.graphics.PdfImageType;
import com.spire.presentation.FileFormat;
import com.spire.presentation.Presentation;
import com.spire.xls.Workbook;
import lombok.SneakyThrows;
import org.bytedeco.javacv.FFmpegFrameGrabber;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.Java2DFrameConverter;
import org.springframework.util.Assert;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 * @description: office文档缩略图生成工具
 * @author: Mr.404
 * @create: 2024-12-13 15:08
 **/
public class SpireThumbnailUtil {

    // 定义日期时间格式化字符串，用于生成时间戳部分的文件名
    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");

    private static String buildPicPath(File file, String fileType) {
        String fileBasePath = file.getParent() + File.separator;
        String timestamp = LocalDateTime.now().format(DATE_TIME_FORMATTER);
        return String.format("%s%s-%s-%s.png", fileBasePath, timestamp, fileType,
            file.getName().substring(0, file.getName().lastIndexOf(".")));
    }

    @SneakyThrows
    public static String wordToImage(File wordFile) {
        Document word = new Document(wordFile.getAbsolutePath());
        System.out.println("word.getPageCount() = " + word.getBuiltinDocumentProperties().getPageCount());

        BufferedImage image = word.saveToImages(0, ImageType.Bitmap);
        String imgUrl = buildPicPath(wordFile, "word");
        File file = new File(imgUrl);
        ImageIO.write(image, "PNG", file);
        System.out.println("word imgUrl：" + imgUrl);
        return imgUrl;
    }

    @SneakyThrows
    public static String pdfToImage(File pdfFile) {
        PdfDocument pdf = new PdfDocument(pdfFile.getAbsolutePath());
        System.out.println("pdf.getPages().getCount() = " + pdf.getPages().getCount());
        BufferedImage image = pdf.saveAsImage(0, PdfImageType.Bitmap);
        String imgUrl = buildPicPath(pdfFile, "pdf");
        File file = new File(imgUrl);
        ImageIO.write(image, "PNG", file);
        System.out.println("pdf imgUrl：" + imgUrl);
        return imgUrl;
    }

    @SneakyThrows
    public static String excelToImage(File excelFile) {
        Workbook workbook = new Workbook();
        workbook.loadFromFile(excelFile.getAbsolutePath());
        System.out.println("workbook.getWorksheets().getCount() = " + workbook.getWorksheets().getCount());

        BufferedImage image = workbook.saveAsImage(0, 100, 100);
        int maxWidth = image.getWidth();
        System.out.println("maxWidth = " + maxWidth);
        int maxHeight = image.getHeight();
        System.out.println("maxHeight = " + maxHeight);
        BufferedImage subimage = image.getSubimage(0, 0, Math.min(maxWidth, 1280), Math.min(maxHeight, 1500));
        String imgUrl = buildPicPath(excelFile, "excel");
        ImageIO.write(subimage, "PNG", new File(imgUrl));
        workbook.dispose();
        System.out.println("excel imgUrl：" + imgUrl);
        return imgUrl;
    }

    @SneakyThrows
    public static String pptToImage(File pptFile) {
        Presentation ppt = new Presentation(pptFile.getAbsolutePath(), FileFormat.AUTO);
        System.out.println("ppt.getSlides().size() = " + ppt.getSlides().size());
        BufferedImage image = ppt.getSlides().get(0).saveAsImage();
        String imgUrl = buildPicPath(pptFile, "ppt");
        ImageIO.write(image, "PNG", new File(imgUrl));
        ppt.dispose();
        System.out.println("ppt imgUrl：" + imgUrl);
        return imgUrl;
    }

    @SneakyThrows
    public static String videoImage(File videoFile) {
        String imgUrl = buildPicPath(videoFile, "video");
        FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(videoFile);
        grabber.start();
        // 获取第一帧
        Frame frame = grabber.grabImage();
        // 获取视频的总时长（单位：微秒）
        long videoDurationInMicroSeconds = grabber.getLengthInTime();
        // 将微秒转换为秒
        long videoDurationInSeconds = videoDurationInMicroSeconds / 1000000;
        // 输出视频时长
        System.out.println("Video Duration: " + videoDurationInSeconds + " seconds");
        // 将 Frame 转换为 BufferedImage
        if (frame == null) {
            return "";
        }
        // 将帧转为 BufferedImage
        BufferedImage bufferedImage = new Java2DFrameConverter().getBufferedImage(frame);
        File output = new File(imgUrl);
        ImageIO.write(bufferedImage, "PNG", output);
        grabber.stop();
        return imgUrl;
    }

    public static String generateThumbnail(String filePath) {
        File file = new File(filePath);
        Assert.isTrue(file.exists(), "文件不存在");
        String picPath = "";
        if (filePath.endsWith("doc") || filePath.endsWith("docx")) {
            picPath = wordToImage(file);
        } else if (filePath.endsWith("pdf")) {
            picPath = pdfToImage(file);
        } else if (filePath.endsWith("xlsx") || filePath.endsWith("xls")) {
            picPath = excelToImage(file);
        } else if (filePath.endsWith("ppt") || filePath.endsWith("pptx")) {
            picPath = pptToImage(file);
        } else if (filePath.endsWith("mp4") || filePath.endsWith("avi")) {
            picPath = videoImage(file);
        }
        return picPath;
    }

    public static void main(String[] args) throws Exception {
        generateThumbnail("D:\\tmp\\1.docx");
        generateThumbnail("D:\\tmp\\1.pdf");
        generateThumbnail("D:\\tmp\\1.xlsx");
        generateThumbnail("D:\\tmp\\1.pptx");
        generateThumbnail("D:\\tmp\\1.mp4");
        generateThumbnail("D:\\tmp\\1.avi");
    }
}