JAVA 实现PDF转图片(pdfbox版)

超、凢脫俗 2024-02-20 11:39 68阅读 0赞

依赖：

![826344e6064479f486f57cadc0abe313.png][]

pdf存放路径

![ef317d765fa305f313141b311431aeee.png][]

正文开始：

pdf转换多张图片、长图

@Test
    void pdf2Image() {
            String dstImgFolder = "";
            String PdfFilePath = "";
     
            String relativelyPath=System.getProperty("user.dir");
            PdfFilePath = relativelyPath + "/uploadTest/"+"文档.pdf";
            dstImgFolder = relativelyPath + "/uploadTest/";
            /* dpi越大转换后越清晰，相对转换速度越慢 */
            int dpi = 450;
            File file = new File(PdfFilePath);
            PDDocument pdDocument; // 创建PDF文档
            try {
                String imgPDFPath = file.getParent();
                int dot = file.getName().lastIndexOf('.');
                String imagePDFName = file.getName().substring(0, dot); // 获取图片文件名
                String imgFolderPath = null;
                if (dstImgFolder.equals("")) {
                    imgFolderPath = imgPDFPath + File.separator;// 获取图片存放的文件夹路径
                } else {
                    imgFolderPath = dstImgFolder + File.separator;
                }
                if (createDirectory(imgFolderPath)) {
                    pdDocument = PDDocument.load(file);
                    PDFRenderer renderer = new PDFRenderer(pdDocument);
                    PdfReader reader = new PdfReader(PdfFilePath);
                    int pages = reader.getNumberOfPages();
                    StringBuffer imgFilePath = null;
                   BufferedImage[] bufferedImages = new BufferedImage[pages];
                    for (int i = 0; i < pages; i++) {
                        String imgFilePathPrefix = imgFolderPath + File.separator;
                        imgFilePath = new StringBuffer();
                        imgFilePath.append(imgFilePathPrefix);
                        imgFilePath.append("_");
                        imgFilePath.append(i + 1);
                        imgFilePath.append(".png");
                        // File dstFile = new File(imgFilePath.toString());
                        BufferedImage image = renderer.renderImageWithDPI(i, dpi);
                       bufferedImages[i] = image;
                        // ImageIO.write(image, "png", dstFile);
                    }
                    dstImgFolder = dstImgFolder + imagePDFName + ".png";
                    // PDF文件全部页数转PNG图片，若多张展示注释即可 工具类贴在下面
                   ImageMergeUtil.mergeImage(bufferedImages, 2, dstImgFolder);
                    System.out.println("PDF文档转PNG图片成功！");
                } else {
                    System.out.println("PDF文档转PNG图片失败：" + "创建" + imgFolderPath + "失败");
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
     
        private static boolean createDirectory(String folder) {
            File dir = new File(folder);
            if (dir.exists()) {
                return true;
            } else {
                return dir.mkdirs();
            }
        }

// ImageMergeUtil 图片的合并，多张图片合成长图
    import javax.imageio.ImageIO;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
     
    public class ImageMergeUtil {
        public static void main(String[] args) throws IOException {
            String filePath = "D:\\temp\\ImageMergeUtil\\";
            String path1 = filePath + "a.png";
            String path2 = filePath + "b.png";
            mergeImage(path1, path2,  2, filePath+"c.png");
        }
     
        /**
         * 图片拼接
         * @param path1     图片1路径
         * @param path2     图片2路径
         * @param type      1 横向拼接， 2 纵向拼接
         * （注意：必须两张图片长宽一致）
         */
        public static void mergeImage( String path1, String path2, int type, String targetFile) throws IOException {
            File file1 = new File(path1);
            File file2 = new File(path2);
            //两张图片的拼接
            int len = 2;
            BufferedImage[] images = new BufferedImage[len];
            images[0] = ImageIO.read(file1);
            images[1] = ImageIO.read(file2);
            mergeImage(images, type, targetFile);
     
        }
     
        /**
         * 图片拼接
         * @param images     图片数组
         * @param type      1 横向拼接， 2 纵向拼接
         * （注意：必须两张图片长宽一致）
         */
        public static void mergeImage(BufferedImage[] images, int type, String targetFile) throws IOException {
            int len = images.length;
            int[][] ImageArrays = new int[len][];
     
            for (int i = 0; i < len; i++) {
                int width = images[i].getWidth();
                int height = images[i].getHeight();
                ImageArrays[i] = new int[width * height];
                ImageArrays[i] = images[i].getRGB(0, 0, width, height, ImageArrays[i], 0, width);
            }
            int newHeight = 0;
            int newWidth = 0;
            for (int i = 0; i < images.length; i++) {
                // 横向
                if (type == 1) {
                    newHeight = newHeight > images[i].getHeight() ? newHeight : images[i].getHeight();
                    newWidth += images[i].getWidth();
                } else if (type == 2) {// 纵向
                    newWidth = newWidth > images[i].getWidth() ? newWidth : images[i].getWidth();
                    newHeight += images[i].getHeight();
                }
            }
            if (type == 1 && newWidth < 1) {
                return;
            }
            if (type == 2 && newHeight < 1) {
                return;
            }
            // 生成新图片
            try {
                BufferedImage ImageNew = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);
                int height_i = 0;
                int width_i = 0;
                for (int i = 0; i < images.length; i++) {
                    if (type == 1) {
                        ImageNew.setRGB(width_i, 0, images[i].getWidth(), newHeight, ImageArrays[i], 0,
                                images[i].getWidth());
                        width_i += images[i].getWidth();
                    } else if (type == 2) {
                        ImageNew.setRGB(0, height_i, newWidth, images[i].getHeight(), ImageArrays[i], 0, newWidth);
                        height_i += images[i].getHeight();
                    }
                }
     
                //输出想要的图片
                ImageIO.write(ImageNew, "png", new File(targetFile));
            } catch (Exception e) {
     
                e.printStackTrace();
            }
        }

展示效果：

![4d5842289b49aa77324ba22d9f0ba563.png][]

附加：小程序预览[wxml][]代码

![16cbbf6022d04288cdf95001a3785cec.png][]

[826344e6064479f486f57cadc0abe313.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/de4f1c740c844bc4b8d63cdc2af917a3.png
[ef317d765fa305f313141b311431aeee.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/1bc2c4074f034137b4a12bd15dbee0ad.png
[4d5842289b49aa77324ba22d9f0ba563.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/7fd38cfaba9d4c69b12f9b82dc40c22b.png
[wxml]: https://so.csdn.net/so/search?q=wxml&spm=1001.2101.3001.7020
[16cbbf6022d04288cdf95001a3785cec.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/d77f51d02307434ab969c2cd1b5f69d6.png