RecomTree: Socket-Based Movie Recommendation System

Course: Project 63-31 Collaborative Programming (Fall 2025) Topic: Socket-Based Movie Recommendation System

👥 Authors

• Elia Pfamatter
• Vuk Vasic

📖 Project Description

RecomTree is a Java-based client-server application that simulates the core mechanisms of a movie recommendation platform, inspired by Netflix's recommender system.

The system maintains a hierarchical N-ary Genre Tree to represent the movie catalog. It allows multiple clients to connect via TCP sockets to browse genres, rate movies, and receive automated recommendations based on specific strategies.

🚀 Key Features

• Multi-Client Support: Handles multiple concurrent clients using Java TCP Sockets (ServerSocket, Socket).
• Data Structure: Implements a custom N-ary Tree (GenreTree) to manage genres and subgenres efficiently.
• Recommendation Engine: Generates suggestions using configurable strategies (e.g., Top-Rated, Genre-Similar).
• Interactive CLI: Clients can add movies, rate titles, and request recommendations via a text-based interface.
• SOLID Design: Built with strict adherence to modular architecture and design patterns.

🛠 Architecture & Design Patterns

This project enforces SOLID principles and utilizes the following design patterns:

1. Composite Pattern: Used in the GenreTree and GenreNode structure to treat individual movies and genre hierarchies uniformly.
2. Command Pattern: Used to parse and execute client requests (e.g., AddMovieCommand, RecommendCommand), ensuring loose coupling between the request and the execution logic.
3. Strategy Pattern: Used in the recommendation package to switch between different recommendation algorithms (TopRatedStrategy, GenreSimilarStrategy) at runtime.

📂 Project Structure

The project is organized into the following packages:

src/
├── client/
│   └── RecomTreeClient.java      # Handles TCP connection and user input
├── server/
│   ├── RecomTreeServer.java      # Main server loop
│   └── ClientHandler.java        # Manages individual client threads
├── command/
│   ├── Command.java              # Command Interface
│   ├── CommandFactory.java       # Creates commands from requests
│   └── [ConcreteCommands].java   # (AddMovie, ListSubtree, RateMovie, etc.)
├── recomTree/ (Model)
│   ├── GenreTree.java            # Manager for the N-ary tree
│   ├── GenreNode.java            # Nodes representing Genres
│   └── Movie.java                # Data object for Movie details
└── recommendation/
    ├── RecommendationStrategy.java # Strategy Interface
    └── [Strategies].java         # Concrete algorithms