• 日期: 2025-02-03
  • 标签: 常规

以下是一个使用 Java 8 Spring Boot 实现接收 PDF、DOC、PPT 文件并将每一页转换为图片并保存到指定目录的完整示例代码。

依赖项

首先，您需要在 pom.xml 文件中添加以下依赖项：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>4.1.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>4.1.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.pdfbox</groupId>
        <artifactId>pdfbox</artifactId>
        <version>2.0.24</version>
    </dependency>
</dependencies>

控制器类

创建一个名为 FileUploadController 的控制器类，并在其中添加一个处理文件上传请求的 POST 方法：

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import org.apache.poi.hwpf.extractor.WordExtractor;
import org.apache.poi.xslf.usermodel.XMLSlideShow;
import org.apache.poi.xslf.usermodel.XSLFSlide;
import org.apache.poi.xwpf.usermodel.XWPFDocument;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

@Controller
public class FileUploadController {

    @Value('${upload.dir}')
    private String uploadDir;

    @PostMapping('/upload')
    public String uploadFile(@RequestParam('file') MultipartFile file) throws IOException {
        String originalFilename = file.getOriginalFilename();
        String extension = originalFilename.substring(originalFilename.lastIndexOf('.') + 1).toLowerCase();

        switch (extension) {
            case 'pdf':
                return savePdf(file);
            case 'doc':
                return saveDoc(file);
            case 'docx':
                return saveDocx(file);
            case 'ppt':
                return savePpt(file);
            case 'pptx':
                return savePptx(file);
            default:
                throw new IllegalArgumentException('Unsupported file type: ' + extension);
        }
    }

    private String savePdf(MultipartFile file) throws IOException {
        String filename = UUID.randomUUID().toString() + '.pdf';
        String filepath = uploadDir + File.separator + filename;
        file.transferTo(new File(filepath));

        PDDocument document = PDDocument.load(new File(filepath));
        PDFRenderer renderer = new PDFRenderer(document);
        for (int i = 0; i < document.getNumberOfPages(); i++) {
            BufferedImage image = renderer.renderImage(i);
            String pageFilename = UUID.randomUUID().toString() + '.jpg';
            String pageFilepath = uploadDir + File.separator + pageFilename;
            ImageIO.write(image, 'jpg', new File(pageFilepath));
        }
        document.close();

        return 'redirect:/gallery';
    }

    private String saveDoc(MultipartFile file) throws IOException {
        String filename = UUID.randomUUID().toString() + '.doc';
        String filepath = uploadDir + File.separator + filename;
        file.transferTo(new File(filepath));

        WordExtractor extractor = new WordExtractor(new FileInputStream(filepath));
        String[] paragraphs = extractor.getParagraphText();
        for (int i = 0; i < paragraphs.length; i++) {
            BufferedImage image = TextToImageConverter.convertTextToImage(paragraphs[i]);
            String pageFilename = UUID.randomUUID().toString() + '.jpg';
            String pageFilepath = uploadDir + File.separator + pageFilename;
            ImageIO.write(image, 'jpg', new File(pageFilepath));
        }

        return 'redirect:/gallery';
    }

    private String saveDocx(MultipartFile file) throws IOException {
        String filename = UUID.randomUUID().toString() + '.docx';
        String filepath = uploadDir + File.separator + filename;
        file.transferTo(new File(filepath));

        XWPFDocument document = new XWPFDocument(new FileInputStream(filepath));
        String[] paragraphs = document.getParagraphs().stream().map(p -> p.getText()).toArray(String[]::new);
        for (int i = 0; i < paragraphs.length; i++) {
            BufferedImage image = TextToImageConverter.convertTextToImage(paragraphs[i]);
            String pageFilename = UUID.randomUUID().toString() + '.jpg';
            String pageFilepath = uploadDir + File.separator + pageFilename;
            ImageIO.write(image, 'jpg', new File(pageFilepath));
        }

        return 'redirect:/gallery';
    }

    private String savePpt(MultipartFile file) throws IOException {
        String filename = UUID.randomUUID().toString() + '.ppt';
        String filepath = uploadDir + File.separator + filename;
        file.transferTo(new File(filepath));

        XMLSlideShow slideShow = new XMLSlideShow(new FileInputStream(filepath));
        for (XSLFSlide slide : slideShow.getSlides()) {
            BufferedImage image = slide.getThumbnail(1, 1);
            String pageFilename = UUID.randomUUID().toString() + '.jpg';
            String pageFilepath = uploadDir + File.separator + pageFilename;
            ImageIO.write(image, 'jpg', new File(pageFilepath));
        }

        return 'redirect:/gallery';
    }

    private String savePptx(MultipartFile file) throws IOException {
        String filename = UUID.randomUUID().toString() + '.pptx';
        String filepath = uploadDir + File.separator + filename;
        file.transferTo(new File(filepath));

        XMLSlideShow slideShow = new XMLSlideShow(new FileInputStream(filepath));
        for (XSLFSlide slide : slideShow.getSlides()) {
            BufferedImage image = slide.getThumbnail(1, 1);
            String pageFilename = UUID.randomUUID().toString() + '.jpg';
            String pageFilepath = uploadDir + File.separator + pageFilename;
            ImageIO.write(image, 'jpg', new File(pageFilepath));
        }

        return 'redirect:/gallery';
    }
}

辅助类

创建一个名为 TextToImageConverter 的辅助类，用于将文本转换为图像：

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;

public class TextToImageConverter {

    public static BufferedImage convertTextToImage(String text) {
        int width = 500;
        int height = 50;

        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = image.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        g2d.setBackground(Color.WHITE);
        g2d.clearRect(0, 0, width, height);
        g2d.setColor(Color.BLACK);

        Font font = new Font('Serif', Font.BOLD, 18);
        g2d.setFont(font);

        int x = 10;
        int y = 20;
        for (String line : text.split('
')) {
            g2d.drawString(line, x, y);
            y += g2d.getFontMetrics().getHeight();
        }

        g2d.dispose();

        return image;
    }

}

配置文件

最后，在 application.properties 文件中添加一个配置，以指定上传文件的目标目录：

upload.dir=/path/to/upload/directory

运行程序

现在，您已经准备好运行这个程序了。您可以使用任何 HTTP 客户端（例如 Postman）向 /upload 端点发送文件上传请求。程序会将每个文件转换为图像并将其保存到指定的目录中。

注意： 确保您已经配置了 upload.dir 属性，并且您的应用程序具有写入该目录的权限。

代码说明

  • 该示例代码使用 Apache POI 和 Apache PDFBox 库来读取和转换文档。
  • 代码中使用 UUID 来生成随机文件名，以避免文件名冲突。
  • TextToImageConverter 辅助类用于将文本转换为图像。
  • 您可以根据需要修改代码，例如更改图片格式、添加错误处理等。

总结

本文详细介绍了如何使用 Java 8 Spring Boot 实现接收 PDF、DOC、PPT 文件并将每一页转换为图片并保存到指定目录。希望本文能帮助您快速上手。

Java Spring Boot PDF, DOC, PPT 文件转图片并保存：完整示例和代码

原文地址: https://www.cveoy.top/t/topic/mg7J 著作权归作者所有。请勿转载和采集!

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