Server Transfer - Java File Transfer System (Client-Server)

Project for UNIFI(University of Florence) Software Engineering exam

Introduction

A multithreaded Java client-server application that allows users to navigate server directories, authenticate, and download/upload files. It supports concurrent clients, role-based permissions (User/Admin), and uses software design patterns such as Singleton, Factory & Command, and Observer.

Features

• 🔐 User authentication using a local credentials.txt file
• 📁 Directory navigation on the server side
• ⬇️ Download files from the server
• ⬆️ Upload files (Admins only)
• 🗑️ Delete files (Admins only)
• 👁️ Observer Pattern for Users actions logging
• 🧠 Design Patterns Used:
  • Singleton – for server instance
  • Factory & Command – to manage command creation
  • Observer – to log downloads

🛠️ How to Run

✅ Requirements

• Java 11 or above
• Maven required

🖥️ Start the Server

1. Open the project in IntelliJ
2. Run the Server.java class:
   • This starts listening on port 12345
3. The server creates:
   • A server_files folder (if not present)
   • A credentials.txt file for user management

🧑‍💻 Start the Client

1. Run the Client.java class
2. When prompted:
   • Choose a download folder
   • Login or register
3. Use the command-line interface to:
   • Navigate folders (cd)
   • List files (list)
   • Download (download <filename>)
   • Upload / delete (if Admin)