针对pdf（.pdf）、word（.docx，.doc），ppt（.pptx）文件按页转图片实现策略

对于大文件来说，如果需要加载完整个文件，用户体验将会是一个非常大的问题，针对这个问题，博主对.pdf .docx .doc .pptx文件做了按页分割，对于excel 文件后续持续更新

上源码

import com.aspose.words.Document;
import com.aspose.words.ImageSaveOptions;
import com.aspose.words.SaveFormat;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;
import org.apache.poi.xslf.usermodel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

/**
 * 
Description
 * 
office 相关工具类
 * ======================
 * ======================
 *
 * @Author created by lgy
 * @Date 2019/12/6
 */
public class OfficeUtil {

    private static final Logger log = LoggerFactory.getLogger(OfficeUtil.class);

//    public static void main(String[] args) {
////        doPPTtoImage("D:\\1.pptx", "D:\\ppt", "test", "jpg");
//        doWordToImage("D:\\1.docx", "D:\\ppt", "word", "jpg");
////        doPdfToImage("D:\\1.pdf", "D:\\ppt", "pdf", "jpg");
//    }

    /**
     * PPT转图片(目前仅支持 .pptx)
     *
     * @param pptPath 待转图片ppt的路径
     * @param path    存放路径
     * @param picName 图片前缀名称 如 a 生成后为a_1,a_2 ...
     * @param picType 转成图片的类型，无点 如 jpg bmp png ...
     * @return true/false
     */
    public static boolean doPPTtoImage(String pptPath, String path, String picName, String picType) {
        log.info("PPT转Image 》》》》》》 待转文件pptpath = " + pptPath + " 存放路径imgPath = " + path + " 命名（pickName_i）picName = " + picName + " 图片类型picType = " + picType);
        try {
            Long startTime = new Date().getTime();
            File file = new File(pptPath);
            boolean isppt = checkPPTFile(file);
            if (!isppt) {
                return false;
            }
            File pathFile = new File(path);
            if (!pathFile.exists()) {
                pathFile.mkdirs();
            }
            FileInputStream is = new FileInputStream(file);
            XMLSlideShow xmlSlideShow = new XMLSlideShow(is);
            List<XSLFSlide> xslfSlides = xmlSlideShow.getSlides();
            Dimension pageSize = xmlSlideShow.getPageSize();

            is.close();
            for (int i = 0; i < xslfSlides.size(); i++) {
                setFont(xslfSlides.get(i));
                BufferedImage img = new BufferedImage(pageSize.width,
                        pageSize.height, BufferedImage.TYPE_INT_RGB);

                Graphics2D graphics = img.createGraphics();
                graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
                graphics.setRenderingHint(RenderingHints.KEY_RENDERING,
                        RenderingHints.VALUE_RENDER_QUALITY);
                graphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                        RenderingHints.VALUE_INTERPOLATION_BICUBIC);
                graphics.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS,
                        RenderingHints.VALUE_FRACTIONALMETRICS_ON);

                graphics.setPaint(Color.white);
                graphics.fill(new Rectangle2D.Float(0, 0, pageSize.width,
                        pageSize.height));
                xslfSlides.get(i).draw(graphics);
                File op_img_file = new File(path + "/" +
                        picName + "_" + (i + 1) + "." + picType);
                log.info("imgFile:" + op_img_file);
                FileOutputStream out = new FileOutputStream(op_img_file);
                ImageIO.write(img, picType, out);
                out.close();
            }
            Long endTime = new Date().getTime();
            log.info("PPT转图片花费时间》》》》》》" + (endTime - startTime) + "毫秒");
            return true;
        } catch (Exception e) {
            log.error(e.getMessage());
        }
        return false;
    }

    /**
     * 支持doc  docx文件格式
     *
     * @param wordPath  待转文件world文件路径
     * @param imgPath   存储图片路径
     * @param imageName 图片前缀名称 如 a 生成后为a_1,a_2 ...
     * @param picType   转成图片的类型，无点 如 jpg bmp png ...
     * @return
     */
    public static boolean doWordToImage(String wordPath, String imgPath, String imageName, String picType) {
        log.info("doc / docx 转Image 》》》》》》 待转文件wordPath = " + wordPath + " 存放路径imgPath = " + imgPath + " 命名（pickName_i）picName = " + imageName + " 图片类型picType = " + picType);
        Long startTime = new Date().getTime();
        // licence 授权
        ReadConfigFile.getLicense();
        try {
            Document doc = new Document(wordPath);
            ImageSaveOptions img = new ImageSaveOptions(SaveFormat.JPEG);
            // 设置图片比例以及质量
            img.setScale(3.0F);
            img.setJpegQuality(100);
            // 如果文件路径不存在,则创建
            File file = new File(imgPath);
            if (!file.exists() && !file.isDirectory()) {
                file.mkdirs();
            }
            System.out.println(doc.getPageCount());
            // 将图片保存到文件夹下面
            for (int i = 0; i < doc.getPageCount(); i++) {
                File imgFile = new File(imgPath + "/" + imageName + "_" + i + "." + picType);
                System.out.println(imgFile);
                FileOutputStream fileOS = new FileOutputStream(imgFile);
                img.setPageIndex(i);
                doc.save(fileOS, img);
            }
            Long endTime = new Date().getTime();
            log.info("Word转图片花费时间》》》》》》" + (endTime - startTime) + "毫秒");
            return true;
        } catch (Exception e) {
            log.error(e.getMessage());
        }
        return false;
    }

    /**
     * pdf 转图片
     *
     * @param fileUrl   待转文件pdf文件路径
     * @param imagePath 存储图片路径
     * @param imageName 图片前缀名称 如 a 生成后为a_1,a_2 ...
     * @param imgType   转成图片的类型，无点 如 jpg bmp png ...
     * @return
     */
    public static boolean doPdfToImage(String fileUrl, String imagePath, String imageName, String imgType) {
        PDDocument pdDocument = null;
        /* dpi越大转换后越清晰，相对转换速度越慢 */
        int dpi = 180;
        try {
            pdDocument = getPDDocument(fileUrl);
            PDFRenderer renderer = new PDFRenderer(pdDocument);
            int pages = pdDocument.getNumberOfPages();
            OutputStream sos = null;
            for (int i = 0; i < pages; i++) {
                BufferedImage image = renderer.renderImageWithDPI(i, dpi);
                File file = new File(imagePath + "/" + imageName + "_" + i + "." + imgType);
                System.out.println(file);
                sos = new FileOutputStream(file);
                ImageIO.write(image, imgType, sos);
                sos.close();
            }
            return true;
        } catch (Exception e) {
            log.error(e.getMessage());
        } finally {
            if (pdDocument != null) {
                try {
                    pdDocument.close();
                } catch (IOException e) {
                    log.error(e.getMessage());
                }
            }
        }
        return false;
    }

    /**
     * 设置PPTX字体
     *
     * @param slide
     */
    private static void setFont(XSLFSlide slide) {
        for (XSLFShape shape : slide.getShapes()) {
            if (shape instanceof XSLFTextShape) {
                XSLFTextShape txtshape = (XSLFTextShape) shape;
                for (XSLFTextParagraph paragraph : txtshape.getTextParagraphs()) {
                    List<XSLFTextRun> truns = paragraph.getTextRuns();
                    for (XSLFTextRun trun : truns) {
                        trun.setFontFamily("宋体");
                    }
                }
            }

        }
    }

    /*检测PPT文件*/
    private static boolean checkPPTFile(File file) {
        int pos = file.getName().lastIndexOf(".");
        String extName = "";
        if (pos >= 0) {
            extName = file.getName().substring(pos);
        }
        if (".pptx".equalsIgnoreCase(extName)) {
            return true;
        }
        return false;
    }

    /**
     * 通过PDFbox获取文章总页数
     *
     * @param filePath:文件路径
     * @return
     * @throws IOException
     */
    public static int getNumberOfPages(String filePath) throws IOException {
        PDDocument pdDocument = PDDocument.load(new File(filePath));
        int pages = pdDocument.getNumberOfPages();
        pdDocument.close();
        return pages;
    }

    /**
     * 通过PDFbox生成文件的缩略图
     *
     * @param filePath：文件路径
     * @param outPath：输出图片路径
     * @throws IOException
     */
    public static void getThumbnails(String filePath, String outPath) throws IOException {
        PDDocument pdDocument = null;
        BufferedImage imgTemp = null;
        ImageOutputStream imageout = null;
        try {
            // 利用PdfBox生成图像
            pdDocument = PDDocument.load(new File(filePath));
            PDFRenderer renderer = new PDFRenderer(pdDocument);
            // 构造图片
            imgTemp = renderer.renderImageWithDPI(0, 30, ImageType.RGB);
            // 设置图片格式
            Iterator<ImageWriter> it = ImageIO.getImageWritersBySuffix("png");
            // 将文件写出
            ImageWriter writer = it.next();
            imageout = ImageIO.createImageOutputStream(new FileOutputStream(outPath));
            writer.setOutput(imageout);
            writer.write(new IIOImage(imgTemp, null, null));
        } catch (Exception e) {
            log.error(e.getMessage());
        } finally {
            imgTemp.flush();
            imageout.flush();
            imageout.close();
            pdDocument.close();
        }

    }

    /**
     * 装在pdf对象.
     *
     * @param fileUrl
     * @return
     */
    private static PDDocument getPDDocument(String fileUrl) {
        FileInputStream inputStream = null;
        PDDocument pdf = null;
        try {
            File file = new File(fileUrl);
            inputStream = new FileInputStream(file);
            pdf = PDDocument.load(inputStream);
            return pdf;
        } catch (Exception e) {
            log.error(e.getMessage());
        } finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

}