For your convenience, the documentation is divided into following sections:
Read preface section to discover the problem HFS server was designed to solve. It's a start point if you want to know applicability of the HFS server for your needs.
This section is intended to give you basic understanding of HFS-specific terms, like file storage, communication token, GC, responsibilities of components, etc. If you're new to HFS it is recommended to familiarize yourself with these concepts.
User's guide is for everyone who uses HFS. From this section you will learn how to communicate with HFS server, upload and download files, provide consistency with your application, etc.
Refer to this guide if you need to handle file uploads in Java with Servlet API 3.1. Simple code examples will show you this technology key points just in 15 minutes.