In this short how-to tutorial, an explanation is provided for how to underline text in PDF file using Java. It has the resources for setting the IDE, a list of development steps, and a runnable sample code demonstrating how to add underline in PDF using Java. You will learn the options to perform this task in a newly created PDF file or load an existing file to underline text in it.

Steps to Underline in PDF File using Java

1. Establish the environment to use Aspose.PDF for Java for underlining a text
2. Create a Document and add a page for adding some text to it
3. Instantiate a TextFragment object and set the sample text, the position, and the underline flag
4. Instantiate a TextBuilder object for a particular page and append the filled TextFragment to it
5. Save the resultant PDF file with underlined text

The process of how to underline in PDF document using Java is summarized in these steps. For clarification, a new PDF file is created with a single page, and sample text is added to it using the TextFragment class. Finally, the underline flag is set in the TextFragment object that is subsequently added to the PDF file using the TextBuilder class.

Code to Underline Text in PDF using Java

This code segment elaborates on how to underline text in a PDF using Java. Although, a new PDF file is created for demonstrating this feature, however, you may load an existing PDF file, search for text in it and underline it using the TextFragmentAbsorber class. Similarly, using the TextFragment class you may not only underline the text but change its formatting for highlighting the change.

This code has expressed how to underline in PDF using Java. If you want to learn other operations like highlighting a text in a PDF, refer to the article on how to highlight a PDF document using Java.