Java implements pdf to picture cases

<dependency>
			<groupId></groupId>
			<artifactId>pdfbox</artifactId>
			<version>2.0.15</version>
		</dependency>
		<dependency>
			<groupId></groupId>
			<artifactId>pdfbox-tools</artifactId>
			<version>2.0.15</version>
		</dependency>

    public static List<String> pdf2Img(File pdfFile) {
        if (pdfFile == null || !()) {
            throw new RuntimeException("The pdf file cannot be empty");
        }
        String name = ().substring(0, ().lastIndexOf("."));
        String targetPath = () +  + name;
        List<String> imgList = new ArrayList<>();
        try {
            PDDocument doc = (pdfFile);
            // Number of pages            int pageCount = ();
            PDFRenderer pdfRenderer = new PDFRenderer(doc);
            for (int i = 0; i < pageCount; i++) {
                File targetFile = new File(targetPath +  + name + "-" + (i + 1) + ".jpg");
                if (!().exists()) {
                    (());
                }
                (i);
                BufferedImage image = (i, 105, );
                (image, (), 105);
                (());
            }
        } catch (IOException e) {
            ("File conversion exception", e);
            throw new RuntimeException("File conversion exception，err=" + ());
        }

    /**
      * pdf to a picture
      *
      * @param pdfFile pdf image file
      * @return Image address
      */
    public static String pdf2OneImg(File pdfFile) {

        List<String> imgs = pdf2Img(pdfFile);
        int len = ();
        File[] src = new File[len];
        BufferedImage[] images = new BufferedImage[len];
        int[][] ImageArrays = new int[len][];
        for (int i = 0; i < len; i++) {
            try {
                src[i] = new File((i));
                if (!src[i].exists()) {
                    throw new RuntimeException("document【" + (i) + "】Don't exist");
                }
                images[i] = (src[i]);
            } catch (Exception e) {
                ("", e);
                throw new RuntimeException(e);
            }
            int width = images[i].getWidth();
            int height = images[i].getHeight();
            // Read RGB pixels from the picture            ImageArrays[i] = new int[width * height];
            ImageArrays[i] = images[i].getRGB(0, 0, width, height, ImageArrays[i], 0, width);
        }

        int dst_height = 0;
        int dst_width = images[0].getWidth();
        // Synthesize image pixels        for (int i = 0; i < ; i++) {
            dst_width = dst_width > images[i].getWidth() ? dst_width : images[i].getWidth();
            dst_height += images[i].getHeight();
        }
        if (dst_height < 1) {
            throw new RuntimeException("File synthesis failed，The height of the composite image file=" + dst_height);
        }
        String name = ().substring(0, ().lastIndexOf("."));
        String targetPath = () +  + name;
        // Output path        File outFile = new File(targetPath +  + name + "-");
        // Generate new pictures        try {
            dst_width = images[0].getWidth();
            BufferedImage ImageNew = new BufferedImage(dst_width, dst_height, BufferedImage.TYPE_INT_RGB);
            int height_i = 0;
            for (int i = 0; i < ; i++) {
                (0, height_i, dst_width, images[i].getHeight(), ImageArrays[i], 0, dst_width);
                height_i += images[i].getHeight();
            }
            (ImageNew, "jpg", outFile);
        } catch (Exception e) {
            ("Image merging exception=", e);
            throw new RuntimeException(e);
        }
        return ();
    }