在Java中创建标记的PDF文档
#编程 #api #java #pdf

标记的PDF是一个PDF文件，其中包含有关文档中元素内容的其他元数据。标签是一个无形的标签，可以告诉辅助技术用户页面上的内容。本文将分享如何使用java的spire.pdf编程创建标记的PDF文档。

导入依赖性（2种方法）

（Java的Spire.pdf是一个用于处理PDF文件的商业库。如果要从生成的文档中删除评估消息，则可以contact to get a 30-day trial license。）

方法1： Download the library并解开它。然后将spire.pdf.jar文件添加到您的项目中作为依赖项。

方法2：通过将以下配置添加到pom.xml。 

<repositories>
    <repository>
        <id>com.e-iceblue</id>
        <name>e-iceblue</name>
        <url>https://repo.e-iceblue.com/nexus/content/groups/public/</url>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>e-iceblue</groupId>
        <artifactId>spire.pdf</artifactId>
        <version>8.11.8</version>
    </dependency>
</dependencies>

示例代码

要创建一个标记的PDF文件，您需要首先创建一个 pdftaggedContent 类的对象。然后，使用 pdftaggedContent.getStructureTreot（）。appendChildelement（）方法，将元素添加到根部。完整的示例代码如下所示。

import com.spire.pdf.*;
import com.spire.pdf.graphics.*;
import com.spire.pdf.interchange.taggedpdf.PdfStandardStructTypes;
import com.spire.pdf.interchange.taggedpdf.PdfStructureElement;
import com.spire.pdf.interchange.taggedpdf.PdfTaggedContent;
import com.spire.pdf.tables.PdfTable;

import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

public class CreateTaggedPdf {

    public static void main(String[] args) throws Exception {

        //Create a PdfDocument object
        PdfDocument doc = new PdfDocument();

        //Add a page
        PdfPageBase page = doc.getPages().add(PdfPageSize.A4, new PdfMargins(20));

        //Set tab order
        page.setTabOrder(TabOrder.Structure);

        //Create an object of PdfTaggedContent class
        PdfTaggedContent taggedContent = new PdfTaggedContent(doc);

        //Set language and title for the document
        taggedContent.setLanguage("en-US");
        taggedContent.setTitle("Create Tagged PDF in Java");

        //Set PDF/UA1 identification
        taggedContent.setPdfUA1Identification();

        //Create font and brush
        PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Times New Roman",Font.PLAIN,14), true);
        PdfSolidBrush brush = new PdfSolidBrush(new PdfRGBColor(Color.BLACK));

        //Add a "document" element
        PdfStructureElement document = taggedContent.getStructureTreeRoot().appendChildElement(PdfStandardStructTypes.Document);

        //Add a "heading" element
        PdfStructureElement heading1 = document.appendChildElement(PdfStandardStructTypes.HeadingLevel1);
        heading1.beginMarkedContent(page);
        String headingText = "What Is a Tagged PDF?";
        page.getCanvas().drawString(headingText, font, brush, new Point2D.Float(0, 0));
        heading1.endMarkedContent(page);

        //Add a "paragraph" element
        PdfStructureElement paragraph = document.appendChildElement(PdfStandardStructTypes.Paragraph);
        paragraph.beginMarkedContent(page);
        String paragraphText = "Tagged PDFs can mean the difference between accessing information and " +
                "being unable to do everyday digital tasks like checking your bank balance, " +
                "viewing your statement of benefits from your healthcare provider, accessing college materials, and shopping online." ;

        Rectangle2D.Float rect = new Rectangle2D.Float(0, 30, (float) page.getCanvas().getClientSize().getWidth(), (float) page.getCanvas().getClientSize().getHeight());
        page.getCanvas().drawString(paragraphText, font, brush, rect);
        paragraph.endMarkedContent(page);

        //Add a "table" element
        PdfStructureElement table = document.appendChildElement(PdfStandardStructTypes.Table);
        table.beginMarkedContent(page);
        PdfTable pdfTable = new PdfTable();
        pdfTable.getStyle().getDefaultStyle().setFont(font);
        String[] data = {"Name;Age;Sex",
                "John;22;Male",
                "Katty;25;Female"
        };
        String[][] dataSource = new String[data.length][];
        for (int i = 0; i < data.length; i++) {
            dataSource[i] = data[i].split("[;]", -1);
        }
        pdfTable.setDataSource(dataSource);
        pdfTable.getStyle().setShowHeader(true);
        pdfTable.draw(page.getCanvas(), new Point2D.Float(0, 120), 300f);
        table.endMarkedContent(page);

        //Add a "figure" element
        PdfStructureElement figure = document.appendChildElement(PdfStandardStructTypes.Figure);
        figure.beginMarkedContent(page);
        PdfImage image = PdfImage.fromFile("pdf.jpg");
        page.getCanvas().drawImage(image, new Point2D.Float(0, 200));
        figure.endMarkedContent(page);

        //Save the document to file
        doc.saveToFile("CreatePDFUA.pdf");
    }
}

CreatePDFUA