Add Text Box Annotations to an Existing PDF Document in Java

The previous post have introduced how to add annotations to a PDF document while creating it using a free API. This article will share how to add an annotation to specified text in an existing PDF document using the same API.

Installation (2 methods)

Method 1: Download the free API and unzip it. Then add the Spire.Pdf.jar file to your project as dependency.

Method 2: Directly add the jar dependency to maven project by adding the following configurations to the 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.free</artifactId>
        <version>5.1.0</version>
    </dependency>
</dependencies>

Add a Text Box Annotation to a PDF Document

The annotation text of a text box annotation is displayed directly on the page. The following sample code shows how to find the specified text and then add an annotation to it.

import com.spire.pdf.*;
import com.spire.pdf.annotations.*;
import com.spire.pdf.graphics.*;
import java.awt.*;
import java.awt.geom.*;
import com.spire.pdf.general.find.PdfTextFind;
public class PDFTextBoxAnnotation {
    public static void main(String[] args)  {

        //Create an instance of PdfDocument class 
        PdfDocument doc = new PdfDocument();

        //Load a PDF document
        doc.loadFromFile("Sample.pdf");

        //Get the first page
        PdfPageBase page = doc.getPages().get(0);

        //Find the text to annotate
        PdfTextFind[] find = page.findText("Section Title").getFinds();

        //Create a PdfFreeTextAnnotation object and set the position of the annotation
        float x = (float)(find[0].getPosition().getX() + find[0].getSize().getWidth());
        float y = (float)(find[0].getPosition().getY() + find[0].getSize().getHeight());
        Rectangle2D.Float rect = new Rectangle2D.Float(x, y, 180, 15);
        PdfFreeTextAnnotation textAnnotation = new PdfFreeTextAnnotation(rect);

        //Set the text, font, text color, and text box format of the annotation
        textAnnotation.setMarkupText("Key information about the document");
        PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial",0, 11));
        textAnnotation.setFont(font);
        PdfAnnotationBorder border = new PdfAnnotationBorder(0.3f);
        textAnnotation.setBorder(border);
        textAnnotation.setBorderColor(new PdfRGBColor(Color.pink));
        textAnnotation.setColor(new PdfRGBColor(Color.YELLOW));
        textAnnotation.setOpacity(0.7f);
        textAnnotation.setTextMarkupColor(new PdfRGBColor(Color.black));

        //Add the annotation to the page
        page.getAnnotationsWidget().add(textAnnotation);

        //Save the document
        doc.saveToFile("TextBoxAnnotation.pdf");
        doc.close();
    }
}