Aspose.PDF FOSS
Java
Developer Guide
Annotations

Annotations

This guide shows how to add, configure, and remove PDF annotations using the Annotation class hierarchy in Aspose.PDF FOSS for Java. You will learn to create widget, free-text, highlight, and circle annotations, and to flatten or delete them using PdfAnnotationEditor.

Annotation Hierarchy

The abstract Annotation class is the base for all PDF annotations. All annotations are positioned on a Page at a Rectangle and are added via page.getAnnotations().add(annotation).

WidgetAnnotation

WidgetAnnotation represents a form widget. Appearance is controlled through AppearanceCharacteristics, which exposes setBorder(), setBackground(), setRotate(), and setCaption().

try (Document doc = new Document()) {
    PageCollection pages = doc.getPages();
    Page page = pages.add();
    WidgetAnnotation w = new WidgetAnnotation(page, new Rectangle(0, 0, 100, 50));
    w.getCharacteristics().setBorder(Color.fromRgb(1, 0, 0));
    w.getCharacteristics().setCaption("Submit");
    page.getAnnotations().add(w);
    doc.save("annotated.pdf");
}

FreeTextAnnotation

FreeTextAnnotation displays a text callout at a specified location. It accepts a DefaultAppearance to set the font, size, and color of the annotation text.

DefaultAppearance da = new DefaultAppearance("Helv", 12, Color.BLACK);
FreeTextAnnotation fta = new FreeTextAnnotation(page,
    new Rectangle(50, 50, 200, 100), da);
fta.setContents("Review comment here");
page.getAnnotations().add(fta);

setCallout(double[][]) sets a three-point callout line for the annotation. getIntent() returns the annotation’s FreeTextIntent value.

Markup Annotations

HighlightAnnotation and UnderlineAnnotation mark text spans with quad points. The getQuadPoints() method returns an 8-element array defining the four corners of the marked region.

try (Document doc = new Document("input.pdf")) {
    PageCollection pages = doc.getPages();
    Page page = pages.get(1);
    HighlightAnnotation h = new HighlightAnnotation(page,
        new Rectangle(100, 200, 300, 220));
    page.getAnnotations().add(h);
    doc.save("highlighted.pdf");
}

CircleAnnotation and CaretAnnotation

CircleAnnotation draws an ellipse at the given rectangle; CaretAnnotation marks an insertion point in text. Both extend Annotation and share the same color and border properties.

try (Document doc = new Document()) {
    PageCollection pages = doc.getPages();
    Page page = pages.add();
    CircleAnnotation circle = new CircleAnnotation(page, new Rectangle(100, 100, 200, 200));
    circle.setColor(Color.fromRgb(0, 0, 1));
    page.getAnnotations().add(circle);
    doc.save("circle.pdf");
}

Flattening Annotations

Use PdfAnnotationEditor.flattenAnnotations() to merge all annotations into the page content stream, making them non-editable.

try (PdfAnnotationEditor editor = new PdfAnnotationEditor()) {
    editor.bindPdf("annotated.pdf");
    editor.flattenAnnotations();
    editor.save("flat.pdf");
}

Removing Annotations by Type

Call deleteAnnotations(type) with an annotation type name to remove all annotations of that type from every page in the bound document:

try (PdfAnnotationEditor editor = new PdfAnnotationEditor()) {
    editor.bindPdf("input.pdf");
    editor.deleteAnnotations("Highlight");
    editor.save("output.pdf");
}

See Also

 English