java 实现pdf转化为批量图片（两步走）

微信小程序先看pdf批量转图片效果

1.导入jar包

方法1：在maven中导入

    <dependency>
        <groupId>org.apache.pdfbox</groupId>
        <artifactId>pdfbox</artifactId>
        <version>2.0.12</version>
    </dependency>

方法2：在官网下载 手动导入
官网地址： https://mvnrepository.com/artifact/org.apache.pdfbox/pdfbox

2.代码实现

public class PDFTransformImage {

        /**
         * main方法
         */
        public void main(String[] args) {
            PDFTransformImage pdfTransformImage = new PDFTransformImage();
            pdfTransformImage.pdfToImage("pdf路径(要带上pdf的文件名)", "输出图片路径(路径下找study-0.png的文件)", 150, UUID.randomUUID());
        }

        /**
         * PDF文件转PNG图片，全部页数
         *
         * @param PdfFilePath  pdf完整路径
         * @param dstImgFolder 图片存放的文件夹
         * @param dpi          dpi越大转换后越清晰，相对转换速度越慢
         * @return 返回转换后图片集合list
         */
        public List<File> pdfToImage(String PdfFilePath, String dstImgFolder, int dpi, UUID uuid) {
//        UUID uuid = UUID.randomUUID();
            String uuId = uuid.toString();
            System.out.println(uuId);
            File file = new File(PdfFilePath);
            //定义集合保存返回图片数据
            List<File> fileList = new ArrayList<File>();
            @SuppressWarnings("resource")//抑制警告
            PDDocument pdDocument = new PDDocument();
            try {
                //String imagePDFName = file.getName().substring(0, dot); // 获取图片文件名
                String imgFolderPath = null;
                if (dstImgFolder.equals("")) {
                    imgFolderPath = dstImgFolder + File.separator + uuId;// 获取图片存放的文件夹路径
                } else {
                    imgFolderPath = dstImgFolder + File.separator + uuId;
                }
                if (createDirectory(imgFolderPath)) {
                    pdDocument = PDDocument.load(file);
                    PDFRenderer renderer = new PDFRenderer(pdDocument);
                    /* dpi越大转换后越清晰，相对转换速度越慢 */
                    PdfReader reader = new PdfReader(PdfFilePath);
                    System.out.println("pdf总共多少页-----" + reader.getNumberOfPages());
                    StringBuffer imgFilePath = null;
                    for (int i = 0; i < reader.getNumberOfPages(); i++) {
                        String imgFilePathPrefix = imgFolderPath + File.separator + "study";
//                    System.out.println("imgFilePathPrefix=====" + imgFilePathPrefix);
                        imgFilePath = new StringBuffer();
                        imgFilePath.append(imgFilePathPrefix);
                        imgFilePath.append("-");
                        imgFilePath.append(String.valueOf(i));
                        imgFilePath.append(".jpg");
                        File dstFile = new File(imgFilePath.toString());
                        BufferedImage image = renderer.renderImageWithDPI(i, dpi);
                        ImageIO.write(image, "png", dstFile);
                        fileList.add(dstFile);
                    }
                    System.out.println("PDF文档转PNG图片成功！");
                    return fileList;
                } else {
                    System.out.println("PDF文档转PNG图片失败：" + "创建" + imgFolderPath + "失败");
                    return null;
                }
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }

        //创建文件夹
        private boolean createDirectory(String folder) {
            File dir = new File(folder);
            if (dir.exists()) {
                return true;
            } else {
                return dir.mkdirs();
            }
        }

        //删除文件夹
        //param folderPath 文件夹完整绝对路径
        public void delFolder(String folderPath) {
            try {
                delAllFile(folderPath); //删除完里面所有内容
                String filePath = folderPath;
                filePath = filePath.toString();
                java.io.File myFilePath = new java.io.File(filePath);
                myFilePath.delete(); //删除空文件夹
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        //删除指定文件夹下所有文件
        //param path 文件夹完整绝对路径
        public boolean delAllFile(String path) {
            boolean flag = false;
            File file = new File(path);
            if (!file.exists()) {
                return flag;
            }
            if (!file.isDirectory()) {
                return flag;
            }
            String[] tempList = file.list();
            File temp = null;
            for (int i = 0; i < tempList.length; i++) {
                if (path.endsWith(File.separator)) {
                    temp = new File(path + tempList[i]);
                } else {
                    temp = new File(path + File.separator + tempList[i]);
                }
                if (temp.isFile()) {
                    temp.delete();

                }
                if (temp.isDirectory()) {
                    delAllFile(path + "/" + tempList[i]);//先删除文件夹里面的文件
                    delFolder(path + "/" + tempList[i]);//再删除空文件夹
                    flag = true;
                }
            }
            return flag;
        }

    }