请帮我用java18使用springboot 设计一套docdocxpptpdf上传后每一页按页数重命名后保存为图片到本地的方法

以下是一个基本的实现示例：

1. 添加依赖

首先需要添加POI和Apache Commons FileUpload的依赖：

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>5.0.0</version>
</dependency>
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>

2. 编写控制器

接下来，需要编写一个控制器来处理文件上传和转换为图片的逻辑。在这个示例中，我们将上传的文件存储在临时目录中，并将其转换为图片，并将每一页按页数重命名后保存在本地。

@RestController
@RequestMapping("/upload")
public class FileUploadController {

    @PostMapping("/")
    public ResponseEntity<?> uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
        // 创建临时目录
        File tempDir = Files.createTempDirectory("temp").toFile();

        // 保存上传的文件到临时目录
        File uploadedFile = new File(tempDir, file.getOriginalFilename());
        try (OutputStream os = new FileOutputStream(uploadedFile)) {
            os.write(file.getBytes());
        }

        // 将文件转换为图片
        List<File> imageFiles = convertToImages(uploadedFile);

        // 重命名并保存每一页图片到本地
        for (int i = 0; i < imageFiles.size(); i++) {
            File imageFile = imageFiles.get(i);
            String imageName = String.format("%s_%d.%s", FilenameUtils.getBaseName(imageFile.getName()), i + 1, FilenameUtils.getExtension(imageFile.getName()));
            File renamedImageFile = new File(tempDir, imageName);
            FileUtils.moveFile(imageFile, renamedImageFile);
        }

        // 删除临时目录及其内容
        FileUtils.deleteDirectory(tempDir);

        return ResponseEntity.ok().build();
    }

    private List<File> convertToImages(File file) throws IOException {
        try (InputStream is = new FileInputStream(file)) {
            String extension = FilenameUtils.getExtension(file.getName());
            switch (extension) {
                case "doc":
                case "docx":
                    return convertWordToImages(is);
                case "ppt":
                case "pptx":
                    return convertPowerPointToImages(is);
                case "pdf":
                    return convertPdfToImages(is);
                default:
                    throw new IllegalArgumentException("Unsupported file type: " + extension);
            }
        }
    }

    private List<File> convertWordToImages(InputStream is) throws IOException {
        XWPFDocument document = new XWPFDocument(is);
        XWPFPictureData pictureData = document.getAllPictures().get(0);
        byte[] pictureBytes = pictureData.getData();
        BufferedImage image = ImageIO.read(new ByteArrayInputStream(pictureBytes));
        return Collections.singletonList(createImageFile(image, "png"));
    }

    private List<File> convertPowerPointToImages(InputStream is) throws IOException {
        XMLSlideShow slideShow = new XMLSlideShow(is);
        BufferedImage[] slides = new BufferedImage[slideShow.getSlides().size()];
        for (int i = 0; i < slideShow.getSlides().size(); i++) {
            XSLFSlide slide = slideShow.getSlides().get(i);
            BufferedImage image = new BufferedImage(slideShow.getPageSize().width, slideShow.getPageSize().height, BufferedImage.TYPE_INT_RGB);
            Graphics2D graphics = image.createGraphics();
            graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            graphics.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
            slide.draw(graphics);
            slides[i] = image;
        }
        return Arrays.stream(slides).map(image -> createImageFile(image, "png")).collect(Collectors.toList());
    }

    private List<File> convertPdfToImages(InputStream is) throws IOException {
        PDDocument document = PDDocument.load(is);
        PDFRenderer renderer = new PDFRenderer(document);
        BufferedImage[] pages = new BufferedImage[document.getNumberOfPages()];
        for (int i = 0; i < document.getNumberOfPages(); i++) {
            pages[i] = renderer.renderImage(i);
        }
        return Arrays.stream(pages).map(image -> createImageFile(image, "png")).collect(Collectors.toList());
    }

    private File createImageFile(BufferedImage image, String format) throws IOException {
        File file = File.createTempFile("image", "." + format);
        ImageIO.write(image, format, file);
        return file;
    }

}

3. 测试

最后，可以使用任何HTTP客户端来测试上传文件和转换为图片的功能。以下是一个使用cURL的示例：

curl -F "file=@/path/to/file.docx" http://localhost:8080/upload/

如果一切正常，上传的文件将被存储在临时目录中，并被转换为图片，并且每一页按页数重命名后保存在本地。