Watermarks are used to protect PDF documents or claim their ownership. Also, in various cases, watermarks are added to display the status of a PDF document such as draft, manuscript, etc. In order to automate watermarking, this article covers how to add a text or image watermark to the PDF using Java.
Java API to Add Watermark to PDF
In order to add a watermark to PDF documents, we will use Aspose.PDF for Java. It is a feature-rich API to create, process, and convert PDF files from within the Java applications. You can either download the API’s JAR or install it using the following Maven configurations.
<repository>
<id>AsposeJavaAPI</id>
<name>Aspose Java API</name>
<url>https://repository.aspose.com/repo/</url>
</repository>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-pdf</artifactId>
<version>21.6</version>
</dependency>
Add Text Watermark to PDF in Java
The following are the steps to add a text watermark to PDF using Java.
- Load the PDF using Document class.
- Create an instance of FormattedText class and set watermark text and its properties.
- Create an instance of WatermarkArtifact class.
- Add text to the artifact and set properties such as alignment, rotation angle, opacity, background, etc.
- Add text watermark to the desired page of PDF using Document.getPages().get_Item(index).getArtifacts().add(WatermarkArtifact) method.
- Save the updated PDF document using Document.save(String) method.
The following code sample shows how to add a text watermark to a PDF document.
| // Load PDF document | |
| Document doc = new Document("input.pdf"); | |
| // Create a formatted text | |
| FormattedText formattedText = new FormattedText("Confidential Document", java.awt.Color.RED, FontStyle.Courier, EncodingType.Identity_h, true, 40.0F); | |
| // Create watermark artifact and set its properties | |
| WatermarkArtifact artifact = new WatermarkArtifact(); | |
| artifact.setText(formattedText); | |
| artifact.setArtifactHorizontalAlignment (HorizontalAlignment.Center); | |
| artifact.setArtifactVerticalAlignment (VerticalAlignment.Center); | |
| artifact.setRotation (25); | |
| artifact.setOpacity (0.5); | |
| artifact.setBackground (false); | |
| // Add watermark to the first page of PDF | |
| doc.getPages().get_Item(1).getArtifacts().add(artifact); | |
| // Save watermarked PDF document | |
| doc.save("watermark.pdf"); |
Output
The following is the screenshot of the watermarked PDF.
Add Image Watermark to PDF in Java
The following are the steps to add an image watermark to PDF using Java.
- Load the PDF using Document class.
- Create an instance of BackgroundArtifact class and set its background image and other properties.
- Add image watermark to the desired page of PDF using Document.getPages().get_Item(index).getArtifacts().add(BackgroundArtifact) method.
- Save the updated PDF document using Document.save(String) method.
The following code sample shows how to add an image watermark to a PDF document.
| // Load PDF document | |
| Document doc = new Document("input.pdf"); | |
| // Create a background artifact | |
| BackgroundArtifact background = new BackgroundArtifact(); | |
| // Specify the image for background artifact object | |
| background.setBackgroundImage(new FileInputStream("logo.png")); | |
| background.setOpacity(0.5); | |
| background.setArtifactHorizontalAlignment(HorizontalAlignment.Center); | |
| background.setArtifactVerticalAlignment(VerticalAlignment.Center); | |
| // Add watermark to the first page of PDF | |
| doc.getPages().get_Item(1).getArtifacts().add(background); | |
| // Save watermarked PDF document | |
| doc.save("watermark.pdf"); |
Output
The following is the screenshot of the watermarked PDF.
Get a Free API License
You can get a temporary license in order to use the API without evaluation limitations.
Conclusion
In this article, you have learned how to add a text or image watermark to a PDF using Java. Also, you have seen how to customize the appearance of the watermark using different properties. You can learn more about the Java PDF API using the documentation. In case you would have any questions, let us know via our forum.