Watermarks

ARender supports watermarking documents at viewing time and on downloaded PDFs. Watermarks are rendered as repeated stamp annotations overlaid on each page.

Default watermark

ARender ships with a built-in watermark whose content is:

Viewed by $USERNAME$ at $TIMESTAMP$

$USERNAME$ is replaced with the authenticated user name. $TIMESTAMP$ is replaced with the current date and time.

Enabling the default watermark

Enable watermarking in the server configuration (arender-custom-server.properties):

arender.watermark.activate.on.startup=true
arender.server.process.annotations.rendition=true

Restart the ARender web application. For the full list of watermark properties, see Viewer configuration — Watermark.

Custom watermark

You can define your own watermark by declaring a Spring bean in arender-custom-server-integration.xml. The bean controls the text content, style, and position.

arender-custom-server-integration.xml

<bean id="myWatermark" class="com.arondor.viewer.client.api.annotation.templates.AnnotationTemplate">
  <property name="name" value="MY_WATERMARK" />
  <property name="annotationType">
    <value type="com.arondor.viewer.annotation.common.AnnotationType">Stamp</value>
  </property>
  <property name="contentTemplate" value="CONFIDENTIAL - $USERNAME$" />
  <property name="annotationStyle">
    <bean class="com.arondor.viewer.client.api.annotation.AnnotationStyle">
      <property name="fontColor" value="black" />
      <property name="fontSize" value="20" />
      <property name="backgroundColor" value="none" />
      <property name="borderColor" value="black" />
      <property name="borderStyle" value="0" />
      <property name="borderWidth" value="0" />
      <property name="rotation" value="340" />
    </bean>
  </property>
  <!-- Available values: CENTER, TOP_LEFT -->
  <property name="watermarkPosition" value="CENTER" />
</bean>

Style properties

Property	Description	Example values
fontColor	Text color	black, rgb(255,0,0)
fontSize	Font size in points	20, 80
backgroundColor	Background behind text	none, white
borderColor	Border color	black
borderWidth	Border width (0 to hide)	0, 1
rotation	Rotation angle in degrees	340 (diagonal), 0

Template variables

Variable	Replaced with
$USERNAME$	Current authenticated user
$TIMESTAMP$	Current date and time

Activating a custom watermark

Set arender.watermark.bean.name=myWatermark in arender-custom-server.properties and restart the web application. See Viewer configuration — Watermark for all available properties.

Programmatic watermark creation (REST client)

You can generate watermarked PDFs server-side using the arondor-arender-client-javarest dependency. This approach creates stamp annotations on every page and burns them into a new PDF via the rendition server.

1. Initialize the client and load the document

RenditionRestClient client = new RenditionRestClient();
client.setAddress("http://localhost:8761");

InputStream data = /* your document binary */;
DocumentAccessor original = new DocumentAccessorByteArray(data);
client.loadDocumentAccessor(original);

DocumentAccessor accessorConverted =
    client.getDocumentAccessor(original.getUUID(), DocumentAccessorSelector.RENDERED);

2. Get the page count

DocumentLayout layout = client.getDocumentLayout(accessorConverted.getUUID());
int nbPages;
if (layout instanceof DocumentPageLayout) {
    nbPages = ((DocumentPageLayout) layout).getPageCount();
} else {
    throw new IllegalStateException("Unsupported layout type");
}

3. Configure the stamp style

AnnotationStyle annotationStyle = new AnnotationStyle();
annotationStyle.setFontSize(80);
annotationStyle.setFontColor("rgb(0,0,255)");
annotationStyle.setBackgroundColor("none");
annotationStyle.setBorderWidth(0);

Map<String, String> styleMap = new HashMap<>();
styleMap.put("fontSize", String.valueOf(annotationStyle.getFontSize()));
styleMap.put("fontColor", annotationStyle.getFontColor());
styleMap.put("borderWidth", String.valueOf(annotationStyle.getBorderWidth()));
styleMap.put("borderColor", annotationStyle.getBorderColor());
styleMap.put("backgroundColor", annotationStyle.getBackgroundColor());

StringBuilder appearance = new StringBuilder();
for (Map.Entry<String, String> entry : styleMap.entrySet()) {
    appearance.append(entry.getKey()).append(":").append(entry.getValue()).append(";");
}

4. Create stamp annotations for each page

List<Annotation> stamps = new ArrayList<>();
for (int i = 0; i < nbPages; i++) {
    StampElemType stamp = new StampElemType();
    stamp.setDocumentId(DocumentIdFactory.getInstance().generate());
    stamp.setContents("WATERMARK");
    stamp.setRotation(0);
    stamp.setPosition(new PageRelativePosition(0, 100, 400, 400));
    stamp.setAppearance(appearance.toString());
    stamp.setPage(i);
    stamps.add(stamp);
}

5. Generate the watermarked PDF

AlterContentDescriptionWithAnnotations alterContent =
    new AlterContentDescriptionWithAnnotations();
alterContent.setAnnotations(stamps);

List<DocumentId> sourceIds = new ArrayList<>();
sourceIds.add(accessorConverted.getUUID());

DocumentId renderedDoc = client.alterDocumentContent(sourceIds, alterContent);
DocumentAccessor finalDoc =
    client.getDocumentAccessor(renderedDoc, DocumentAccessorSelector.RENDERED);

// The watermarked PDF binary
InputStream result = finalDoc.getInputStream();

tip

The programmatic approach is useful for batch processing or integrations where you need to produce watermarked PDFs without user interaction through the viewer.