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Getting Started with Java

This guide walks you through editing your first PDF with PDFDancer, from scratch.

What You'll Build​

By the end of this guide, you'll have a working Java application that:

  • Opens a PDF file
  • Finds and replaces text
  • Saves the modified PDF

Prerequisites​

You need Java 11 or higher installed on your computer.

Check your Java version:

java -version

If you see 11 or higher, you're good to go.

Don't have Java? Download it from Adoptium or Oracle.

Step 1: Create a Project Folder​

Open your terminal and create a new folder for your project:

mkdir my-pdf-project
cd my-pdf-project

Step 2: Set Up the Project​

Create a pom.xml file with the PDFDancer dependency:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>my-pdf-project</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.pdfdancer.client</groupId>
            <artifactId>pdfdancer-client-java</artifactId>
            <version>0.2.3</version>
        </dependency>
    </dependencies>
</project>

Step 3: Get a Sample PDF​

You need a PDF file to work with. Either:

  • Use any PDF you already have
  • Create a simple one with Google Docs or Word

Place your PDF in the project folder and name it input.pdf.

Step 4: Write Your First Program​

Create the directory structure and Java file:

mkdir -p src/main/java

Create src/main/java/EditPdf.java with this code:

import com.pdfdancer.client.rest.PDFDancer;
import com.pdfdancer.client.rest.TextParagraphReference;

import java.io.File;
import java.util.List;

public class EditPdf {
    public static void main(String[] args) throws Exception {
        // Open the PDF (no API token needed for anonymous access)
        PDFDancer pdf = PDFDancer.createSession(new File("input.pdf"));

        // Find paragraphs matching a pattern
        List<TextParagraphReference> paragraphs = pdf.page(1)
                .selectParagraphsMatching("Hello");

        // Replace the text if found
        if (!paragraphs.isEmpty()) {
            paragraphs.get(0).edit()
                    .replace("Hello World!")
                    .apply();
        }

        // Save the result
        pdf.save("output.pdf");

        System.out.println("Done! Check output.pdf");
    }
}

What this does:

  1. Opens input.pdf
  2. Looks for any paragraph matching "Hello" on page 1
  3. Replaces that paragraph's text with "Hello World!"
  4. Saves the result as output.pdf

Step 5: Run It​

Compile and run with Maven:

mvn compile exec:java -Dexec.mainClass="EditPdf"

You should see Done! Check output.pdf and find a new file called output.pdf in your folder.

What's Next?​

Now that you have PDFDancer working: