java实现pdf/doc/docx/ppt/pptx转png图片

复制到自己的项目直接调用使用！

1.需要在pom.xml中增加：

        <!-- PDF-PNG-Apache PDFBox-->
        <dependency>
            <groupId>net.sf.cssbox</groupId>
            <artifactId>pdf2dom</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>org.apache.pdfbox</groupId>
            <artifactId>pdfbox</artifactId>
            <version>2.0.27</version>
        </dependency>
        <dependency>
            <groupId>org.apache.pdfbox</groupId>
            <artifactId>pdfbox-tools</artifactId>
            <version>2.0.27</version>
        </dependency>
        <!--word转换为PDF文档-->
        <dependency>
            <groupId>com.documents4j</groupId>
            <artifactId>documents4j-local</artifactId>
            <version>1.0.3</version>
        </dependency>
        <dependency>
            <groupId>com.documents4j</groupId>
            <artifactId>documents4j-transformer-msoffice-word</artifactId>
            <version>1.0.3</version>
        </dependency>

wholeIsPngUtil类

import com.documents4j.api.DocumentType;
import com.documents4j.api.IConverter;
import com.documents4j.job.LocalConverter;
import com.ruoyi.common.enums.LibFileExtEnum;
import com.ruoyi.system.service.CloudStorageService;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import org.apache.poi.xslf.usermodel.*;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class wholeIsPngUtil {

    /**
     * @param fileType            约定文件类型 1-PDF 2-doc/docx 3-ppt/pptx
     * @param fileUrl             网络地址
     * @param cloudStorageService 上传service(此service是我转成PNG后上传到oss的,你们可以根据自己的需要修改)
     * @return
     */
    public static List<String> getViewImageList(Integer fileType, String fileUrl, CloudStorageService cloudStorageService) {
        List<String> list = new ArrayList<>();
        switch (fileType) {
            case 1:
                list = pdfToPNG(cloudStorageService, fileUrl);
                break;
            case 2:
                list = wordToPNG(cloudStorageService, fileUrl);
                break;
            case 3:
                list = pptToPNG(cloudStorageService, fileUrl);
                break;
            default:
                break;
        }
        return list;
    }

    private static String getImageStoreDir() {
        return LibFileExtEnum.IMAGE_PNG.getStoreDir();
    }

    /**
     *
     * @param url 网络地址
     */
    public static List<String> pdfToPNG(CloudStorageService cloudStorageService, String url) {
        List<String> list = new ArrayList<>();
        long startTime = System.currentTimeMillis();
        try {
            URL pdfUrl = new URL(url);
            PDDocument pdDocument = PDDocument.load(pdfUrl.openStream());
            PDFRenderer renderer = new PDFRenderer(pdDocument);
            //总页数
            int pageCount = pdDocument.getNumberOfPages();
            for (int i = 0; i < pageCount; i++) {
                // dpi越高越清晰，转换越慢
                BufferedImage image = renderer.renderImageWithDPI(i, 70); // Windows native DPI
                // 将图片写出到该路径下
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ImageIO.write(image, "png", baos);
                baos.flush();
                byte[] imageInByte = baos.toByteArray();
                baos.close();
                String[] onlineUrls = cloudStorageService.upload(imageInByte, getImageStoreDir(), ".png");
                list.addAll(Arrays.asList(onlineUrls[1]));
            }
            long endTime = System.currentTimeMillis();
            System.out.println("pdfToPng共耗时：" + ((endTime - startTime) / 1000.0) + "秒"); // 转换用时
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }

    /**
     *
     * @param url 文件地址
     */
    public static  List<String> wordToPNG(CloudStorageService cloudStorageService, String url) {
        List<String> list = new ArrayList<>();
        // 将文件地址和文件名拼接成路径 注意：线上环境不能使用\\拼接      // 获取word文档
        try {
            URL wordUrl = new URL(url);
            long startTime = System.currentTimeMillis();
            // 打开生成的 Word 文件
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            //word转pdf
            convertWordToPdf(wordUrl.openStream(),baos);
            baos.flush();
            byte[] imageInByte = baos.toByteArray();
            baos.close();
            ByteArrayInputStream inputStream =new ByteArrayInputStream(imageInByte);
            PDDocument pdDocument = PDDocument.load(inputStream);
            PDFRenderer renderer = new PDFRenderer(pdDocument);
            //总页数
            int pageCount = pdDocument.getNumberOfPages();
            for (int i = 0; i < pageCount; i++) {
                // dpi越高越清晰，转换越慢
                BufferedImage image = renderer.renderImageWithDPI(i, 70); // Windows native DPI
                // 将图片写出到该路径下
                ByteArrayOutputStream baos1 = new ByteArrayOutputStream();
                ImageIO.write(image, "png", baos1);
                baos1.flush();
                byte[] imageInByte1 = baos1.toByteArray();
                baos1.close();
                String[] onlineUrls = cloudStorageService.upload(imageInByte1, getImageStoreDir(), ".png");
                list.addAll(Arrays.asList(onlineUrls[1]));
            }
            long endTime = System.currentTimeMillis();
            System.out.println("WordToPNG共耗时：" + ((endTime - startTime) / 1000.0) + "秒"); // 转换用时
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }

    /**
     * word转pdf
     *
     */
    public static void convertWordToPdf(InputStream stream, ByteArrayOutputStream sourceOutput) {
        String os = System.getProperty("os.name").toLowerCase();
        if (os.contains("win")) {
            // Windows操作系统
            windowsWordToPdf(stream,sourceOutput);
        } else if (os.contains("nix") || os.contains("nux") || os.contains("mac")) {
            System.out.println("读取操作系统");
            // Unix/Linux/Mac操作系统
            linuxWordToPdf(stream,sourceOutput);
        } else {
            // 未知操作系统
            throw new RuntimeException("不支持当前操作系统转换文档。");
        }
    }




    /**
     * 通过documents4j 实现word转pdf -- Windows 环境 需要有 Microsoft Office 服务
     *
     */
    public static void windowsWordToPdf(InputStream stream, ByteArrayOutputStream sourceOutput) {
        try{
            IConverter converter = LocalConverter.builder().build();
            converter.convert(stream)
                    .as(DocumentType.DOCX)
                    .to(sourceOutput)
                    .as(DocumentType.PDF).execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 通过libreoffice 实现word转pdf -- linux 环境 需要有 libreoffice 服务
     *
     */
    public static void linuxWordToPdf(InputStream stream,ByteArrayOutputStream sourceOutput) {
        // 创建临时文件
        File tempFile = createTempFileFromInputStream(stream);
        // 构建LibreOffice的命令行工具命令
        String command = "libreoffice --headless --invisible --convert-to pdf " + tempFile.getAbsolutePath() + " --outdir " + tempFile.getParent();
        System.out.println("转换"+command);
        // 执行转换命令
        try {
            if (!executeLinuxCmd(command)) {
                System.out.println("转换失败");
                throw new IOException("转换失败");
            }
            readPdfFileToByteArrayOutputStream(tempFile,sourceOutput);
        } catch (Exception e) {
            // 清理临时文件
            System.out.println("清理成功");
//            tempFile.delete();
        } finally {
            File pdfFile = new File(tempFile.getParent(), tempFile.getName().replace(".docx", ".pdf"));
            System.out.println("PDF文件目录"+pdfFile.getPath()+"===="+pdfFile);
            //清理转换后的pdf文件
            pdfFile.delete();
            // 清理临时文件，无论是否成功转换
            tempFile.delete();
        }
    }



    /**
     * 执行命令行
     *
     * @param cmd 命令行
     * @return
     * @throws IOException
     */
    private static boolean executeLinuxCmd(String cmd) throws IOException {
        Process process = Runtime.getRuntime().exec(cmd);
        try {
            process.waitFor();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            return false;
        }
        return true;
    }

    /**
     *
     * 创建临时文件
     */
    private static File createTempFileFromInputStream(InputStream inputStream) {
        try {
            File tempFile = File.createTempFile("temp_word", ".docx");
            Files.copy(inputStream, tempFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
            System.out.println("创建临时文件目录："+tempFile.getPath() +"====="+tempFile +"=====");
            return tempFile;
        } catch (IOException e) {
            throw new RuntimeException("创建临时文件失败", e);
        }
    }

    /**
     * 读取pdf文件
     */
    private static void readPdfFileToByteArrayOutputStream(File tempFile,ByteArrayOutputStream sourceOutput){
        try {
            Path outputFile = Paths.get(tempFile.getParent(), tempFile.getName().replace(".docx", ".pdf"));
            Files.copy(outputFile, sourceOutput);
            System.out.println("读取临时文件："+"====="+tempFile.getParent());
        } catch (Exception e) {
            System.out.println("读取临时文件失败："+"====="+tempFile.getParent());
            throw new RuntimeException(e);
        }
    }


    /**
     * 自由确定起始页和终止页
     *
     * @param url 文件地址
     */
    public static List<String> pptToPNG(CloudStorageService cloudStorageService, String url) {
        List<String> list = new ArrayList<>();
        long startTime = System.currentTimeMillis();
        try {
            URL wordUrl = new URL(url);

            XMLSlideShow xmlSlideShow = new XMLSlideShow(wordUrl.openStream());
            // 获取大小
            Dimension pgsize = xmlSlideShow.getPageSize();
            //总页数
            int size = xmlSlideShow.getSlides().size();
            // 获取幻灯片
            List<XSLFSlide> slides = xmlSlideShow.getSlides();
            for (int i = 0; i < size; i++) {
                // 解决乱码问题
                List<XSLFShape> shapes1 = slides.get(i).getShapes();
                for (XSLFShape shape : shapes1) {
                    if (shape instanceof XSLFTextShape) {
                        XSLFTextShape sh = (XSLFTextShape) shape;
                        List<XSLFTextParagraph> textParagraphs = sh.getTextParagraphs();
                        for (XSLFTextParagraph xslfTextParagraph : textParagraphs) {
                            List<XSLFTextRun> textRuns = xslfTextParagraph.getTextRuns();
                            for (XSLFTextRun xslfTextRun : textRuns) {
                                xslfTextRun.setFontFamily("宋体");
                            }
                        }
                    }
                }
                //根据幻灯片大小生成图片
                BufferedImage img = new BufferedImage(pgsize.width, pgsize.height, BufferedImage.TYPE_INT_ARGB_PRE);
                Graphics2D graphics = img.createGraphics();

                graphics.setPaint(Color.white);
                graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));

                // 最核心的代码
                slides.get(i).draw(graphics);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                // 写入到图片中去
                ImageIO.write(img, "png", baos);
                baos.flush();
                byte[] imageInByte = baos.toByteArray();
                baos.close();
                String[] onlineUrls = cloudStorageService.upload(imageInByte, getImageStoreDir(), ".png");
                list.addAll(Arrays.asList(onlineUrls[1]));
            }
            long endTime = System.currentTimeMillis();
            System.out.println("pptToPNG共耗时：" + ((endTime - startTime) / 1000.0) + "秒"); // 转换用时
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }
}