Java使用pdfbox进行pdf和图片之间的转换

简介

pdfbox是Apache开源的一个项目,支持pdf文档操作功能。
官网地址: Apache PDFBox | A Java PDF Library
支持的功能如下图.
引入依赖

        <dependency><groupId>org.apache.pdfbox</groupId><artifactId>pdfbox-app</artifactId><version>2.0.19</version></dependency>

pdf转换成图片

   /*** 经过测试,dpi为96,100,105,120,150,200中,105显示效果较为清晰,体积稳定,dpi越高图片体积越大,一般电脑显示分辨率为96*/public static final float DEFAULT_DPI = 105;/*** 默认转换的图片格式为jpg*/public static final String DEFAULT_FORMAT = "jpg";/*** pdf转换成图片** @param pdfPath    pdf文件的路径   例如: D:\\test\\test.pdf (2页)* @param targetPath 输出的图片路径        D:\\test\\* @return 抽取出来的图片路径数组         Arrays.asList( "D:\\test\\1.jpg","D:\\test\\2.jpg" )*/public static List<String> pdfToManyImage(String pdfPath, String targetPath) {File file = new File(pdfPath);if (!file.exists()) {return null;}try {//加载pdf文件PDDocument doc = PDDocument.load(file);//读取pdf文件PDFRenderer renderer = new PDFRenderer(doc);int pageCount = doc.getNumberOfPages();List<String> stringList = new ArrayList<>(pageCount);String filePath = null;BufferedImage image;for (int i = 0; i < pageCount; i++) {//96/144/198// Windows native DPIimage = renderer.renderImageWithDPI(i, DEFAULT_DPI);// BufferedImage srcImage = resize(image, 240, 240);//产生缩略图filePath = targetPath + (i + 1) + "." + DEFAULT_FORMAT;//保存图片ImageIO.write(image, DEFAULT_FORMAT, new File(filePath));stringList.add(filePath);}return stringList;} catch (IOException e) {e.printStackTrace();return null;}}

图片合成pdf

    /*** 多图片合成pdf的限制后缀*/private static final List IMAGE_SUFFIX = Arrays.asList("jpg", "png", "jpeg");/*** 多个图片合成一个pdf** @param imgFolder 多图片的文件夹路径  例如:"D:\\image\\"* @param target    合并的图片路径          "D:\\image\\merge.pdf"* @throws IOException*/public static void manyImageToOnePdf(String imgFolder, String target) throws IOException {PDDocument doc = new PDDocument();//创建一个空的pdf文件doc.save(target);PDPage page;PDImageXObject pdImage;PDPageContentStream contents;BufferedImage bufferedImage;String fileName;float w, h;String suffix;File tempFile;int index;File folder = new File(imgFolder);for (int i = 0; i < folder.listFiles().length; i++) {tempFile = folder.listFiles()[i];if (!tempFile.isFile()) {continue;}fileName = tempFile.getName();index = fileName.lastIndexOf(".");if (index == -1) {continue;}//获取文件的后缀suffix = fileName.substring(index + 1);//如果文件后缀不是图片格式,跳过当前循环if (!IMAGE_SUFFIX.contains(suffix)) {continue;}bufferedImage = ImageIO.read(folder.listFiles()[i]);//Retrieving the pagepdImage = LosslessFactory.createFromImage(doc, bufferedImage);w = pdImage.getWidth();h = pdImage.getHeight();page = new PDPage(new PDRectangle(w, h));contents = new PDPageContentStream(doc, page);contents.drawImage(pdImage, 0, 0, w, h);System.out.println("Image inserted");contents.close();doc.addPage(page);}//保存pdfdoc.save(target);//关闭pdfdoc.close();}

多个pdf合成1个pdf

 /*** pdf合并拼接** @param files      pdf文件列表    例如:  Arrays.asList(new File("D:\\1.pdf"),new File("D:\\2.pdf"))* @param targetPath 合并后的文件         D:\\merge.pdf* @return 合并后的文件File对象*/public static File manyPdfToOne(List<File> files, String targetPath) {try {PDFMergerUtility mergePdf = new PDFMergerUtility();for (File f : files) {if (f.exists() && f.isFile()) {// 循环添加要合并的pdfmergePdf.addSource(f);}}// 设置合并生成pdf文件名称mergePdf.setDestinationFileName(targetPath);// 合并pdfmergePdf.mergeDocuments(MemoryUsageSetting.setupMainMemoryOnly());return new File(targetPath);} catch (Exception e) {return null;}}