Add Watermarks to PDF in Java

Watermark artifacts let you place persistent visual markings on a page without mixing them into the main document content.

Extract watermark artifacts from a PDF

Use this example when you need to inspect existing watermark artifacts and read their text or position.

1. Open the source PDF Document.
2. Iterate through the artifact collection of the target page.
3. Filter watermark pagination artifacts and print their text and rectangles.

public static void extractWatermarkFromPdf(Path inputFile) {
    try (Document document = new Document(inputFile.toString())) {
        for (Artifact artifact : document.getPages().get_Item(1).getArtifacts()) {
            if (artifact.getType() == Artifact.ArtifactType.Pagination
                    && artifact.getSubtype() == Artifact.ArtifactSubtype.Watermark) {
                System.out.println(artifact.getText() + " " + artifact.getRectangle());
            }
        }
    }
}

Add a watermark artifact

Use this example when the page should display a centered text watermark with custom rotation, opacity, and background placement.

1. Open the source PDF Document.
2. Create a WatermarkArtifact and configure its text state and placement settings.
3. Add the watermark to the page and save the output file.

public static void addWatermarkArtifact(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        TextState textState = new TextState();
        textState.setFontSize(72);
        textState.setForegroundColor(Color.getBlueViolet());
        textState.setFontStyle(FontStyles.Bold);
        textState.setFont(FontRepository.findFont("Arial"));

        WatermarkArtifact watermark = new WatermarkArtifact();
        watermark.setTextAndState("WATERMARK", textState);
        watermark.setArtifactHorizontalAlignment(HorizontalAlignment.Center);
        watermark.setArtifactVerticalAlignment(VerticalAlignment.Center);
        watermark.setRotation(60);
        watermark.setOpacity(0.2);
        watermark.setBackground(true);

        document.getPages().get_Item(1).getArtifacts().add(watermark);
        document.save(outputFile.toString());
    }
}

Delete watermark artifacts

Use this approach when existing watermark artifacts should be removed from the page.

1. Open the source PDF Document.
2. Iterate through the page artifact collection in reverse order.
3. Delete pagination artifacts whose subtype is watermark, then save the document.

public static void deleteWatermarkArtifact(Path inputFile, Path outputFile) {
    try (Document document = new Document(inputFile.toString())) {
        for (int i = document.getPages().get_Item(1).getArtifacts().size(); i >= 1; i--) {
            Artifact artifact = document.getPages().get_Item(1).getArtifacts().get_Item(i);
            if (artifact.getType() == Artifact.ArtifactType.Pagination
                    && artifact.getSubtype() == Artifact.ArtifactSubtype.Watermark) {
                document.getPages().get_Item(1).getArtifacts().delete(artifact);
            }
        }

        document.save(outputFile.toString());
    }
}