In many professional and academic scenarios, PDF documents often need to carry additional files, such as Excel spreadsheets, PowerPoint slides, or supplementary data. Being able to manage attachments within a PDF can improve document organization, facilitate sharing, and make it easier for recipients to access related materials. In this article, we will explore four practical ways to add and remove attachments in PDF files using Java , covering both direct attachments and annotation-based attachments: Adding a standard attachment to a PDF Attaching a file via annotation Removing standard attachments Removing annotation-based attachments Installing the Required Library To implement these examples, we use Spire.PDF for Java , a library that provides APIs for loading PDF documents, adding attachments, managing annotations, and saving changes.…