How to Add or Remove Annotations from PDF files using Java Leave feedback

There was a time when we used to discuss document content and feedback in long email threads with multiple attachments and different file versions. Now we can simply use annotations to markup the document with messages and replies and send it. In this article, you will learn how to programmatically annotate PDF documents in Java with your application. Additionally, we will see how to remove annotations from PDF files using the same Java API.

To deal with annotations of your document and images within your Java applications, GroupDocs provides GroupDocs.Annotation for Java. Using the API, you can add, remove, and extract annotations from word-processing documents, spreadsheets, presentations, images, email messages, Visio drawings, some AutoCAD, and digital imaging formats like DICOM. Furthermore, the API allows annotating PDF files. You may have a look at the documentation to know about the long list of supported document formats for annotation.

GroupDocs hosts all Java APIs on GroupDocs Repository. You can easily use GroupDocs.Annotation for Java API directly in your Maven projects with simple configurations.

First, you need to specify GroupDocs repository configuration/location in your Maven pom.xml as follows: 

Then define GroupDocs.Annotation for Java API dependency in your pom.xml as follows:

Let’s quickly jump to add some of the different kinds of annotations to the PDF document. As there are many different types of annotation, we may not cover all in this article. I will just mention them, and you may learn about each annotation individually.

• Area / Rectangle annotation
• Arrow
• Distance
• Ellipse
• Highlight
• Link
• Point
• Polyline
• Replacement
• Resource Redaction
• Strikeout
• Text Field
• Text Redaction
• Underline
• Watermark

Let’s start adding some of these in a PDF document.

The following are the steps to add arrow annotation to a PDF document.

• Load the PDF document using the Annotator class.
• Initialize arrow annotation using ArrowAnnotation class.
• Set the position and size of the arrow using Box property of ArrowAnnotation.
• Add the created arrow annotation to the Annotator object.
• Save the annotated PDF by providing the path using the Save method.

The following code sample shows how to add arrow annotation to a PDF document using Java.

You can customize any annotation while adding it to the document. The following are the steps to add rectangle or area annotation to a PDF document with little more customizations. It is similar to adding Arrow annotation but uses AreaAnnotation class in place of ArrowAnnotation.

• Load the PDF document using the Annotator class.
• Initialize rectangle annotation using AreaAnnotation class.
• Set the position and size of the rectangle using Box property of AreaAnnotation.
• Set other properties like PenColor, BackgroundColor, Opacity, PenStyle, PenWidth, and even Replies.
• Add the created rectangle annotation to the Annotator object.
• Save the annotated PDF by providing the path using the Save method.

The following code sample shows how to add rectangle/area annotation to a PDF document using Java.

We have only shown you 2 examples because all the other types of annotation work in a similar way. You can try and add all the other annotations yourself or by following our detailed guides related to every annotation we support.

The following steps show how to remove all the annotations from PDF files in Java.

• Load the PDF document using the Annotator class.
• Initialize saving Options using SaveOptions class.
• Set the annotation types to None.
• Save the PDF file having all the annotations removed, by providing the path using the save method.

The following Java code removes annotations from a PDF file.

In short, you have learned how to add annotations to PDF within Java applications. Further, you have seen how to remove all the annotations from any PDF file. Now, you should be confident to build your own document annotator Java application. It can support different types of annotations using GroupDocs.Annotation for Java.

For more details, options, and examples, you can visit the documentation and the GitHub repository. For further queries, contact the support on the forum.