itext7实现参数和图片替换

前言：

现在有很多pdf版本的协议，需要动态填写用户相关参数和粘贴用户相关图片，如果项目jdk版本为1.6或更低请使用itext5实现，详情见我另外一章itext5实现参数和图片替换的文章，itext7不支持jdk1.6（亲测）；

引入的依赖包如下：

<dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itext7-core</artifactId>
            <version>7.1.2</version>
            <type>pom</type>
        </dependency>

1.参数替换代码：

public class ReplaceStream extends GenericTest {
    public static final String DEST = "./target/test/resources/sandbox/stamper/replace_stream.pdf";
    public static final String SRC = "./src/test/resources/pdfs/hello.pdf";
 
    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new ReplaceStream().manipulatePdf(DEST);
    }
 
    @Override
    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(DEST));
        PdfPage page = pdfDoc.getFirstPage();
        PdfDictionary dict = page.getPdfObject();
        PdfObject object = dict.get(PdfName.Contents);
        if (object instanceof PdfStream) {
            PdfStream stream = (PdfStream) object;
            byte[] data = stream.getBytes();
            stream.setData(new String(data).replace("Hello World", "HELLO WORLD").getBytes("UTF-8"));
        }
        pdfDoc.close();
    }
}

2.图片替换代码

public class ReplaceImage extends GenericTest {
    public static final String DEST = "./target/test/resources/sandbox/images/replace_image.pdf";
    public static final String SRC = "./src/test/resources/pdfs/image.pdf";
 
    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new ReplaceImage().manipulatePdf(DEST);
    }
 
    public static Image makeBlackAndWhitePng(PdfImageXObject image) throws IOException {
        BufferedImage bi = image.getBufferedImage();
        BufferedImage newBi = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_USHORT_GRAY);
        newBi.getGraphics().drawImage(bi, 0, 0, null);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(newBi, "png", baos);
        return new Image(ImageDataFactory.create(baos.toByteArray()));
    }
 
    public static void replaceStream(PdfStream orig, PdfStream stream) throws IOException {
        orig.clear();
        orig.setData(stream.getBytes());
        for (PdfName name : stream.keySet()) {
            orig.put(name, stream.get(name));
        }
    }
 
    @Override
    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
        PdfDictionary page = pdfDoc.getFirstPage().getPdfObject();
        PdfDictionary resources = page.getAsDictionary(PdfName.Resources);
        PdfDictionary xobjects = resources.getAsDictionary(PdfName.XObject);
        PdfName imgRef = xobjects.keySet().iterator().next();
        PdfStream stream = xobjects.getAsStream(imgRef);
        Image img = makeBlackAndWhitePng(new PdfImageXObject(stream));
        replaceStream(stream, img.getXObject().getPdfObject());
        pdfDoc.close();
    }
}