🧠 MemFS - In-Memory File System Simulator

A UNIX-style, in-memory file system simulator built in Java, exposed via RESTful APIs using Spring Boot and a CLI for interactive shell-based access.

Supports core file and directory operations (mkdir, ls, cd, touch, write, cat) with persistence via Java serialization and is fully Dockerized for portable deployment.

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Features

• 🗂️ Simulates a hierarchical file system using an n-ary tree structure
• 🛠️ Shell-like operations: mkdir, cd, ls, touch, cat, write
• 🌐 Exposed via Spring Boot REST APIs
• 💻 Interactive CLI for direct terminal usage
• 💾 Persistent state using Java serialization (filesystem.ser)
• 🐳 Dockerized for consistent deployment

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Tech Stack

• Language: Java 17
• Framework: Spring Boot
• Build Tool: Maven
• Persistence: Java Object Serialization
• Containerization: Docker
• CLI: Java Console (Scanner)

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📂 Project Structure

src/main/java/com/memfs/memfs
├── MemfsApplication.java           # Spring Boot entry point
├── model/
│   └── FileNode.java               # Represents files/directories
├── service/
│   └── FileSystemService.java     # Core logic & persistence
├── controller/
│   └── FileSystemController.java  # REST API layer
└── cli/
    └── MemfsCliRunner.java        # Terminal-based CLI interface

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🌐 REST API Endpoints

Base URL: http://localhost:8080/api/fs

Method	Endpoint	Description
POST	/mkdir	Create directory
GET	/ls	List directory contents
POST	/touch	Create empty file
GET	/cat	Read file content
POST	/write	Write content to file
POST	/cd	Change directory

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CLI Mode

Run MemfsCliRunner to use the interactive shell:

> mkdir projects
> cd projects
> touch readme.txt
> write readme.txt Hello MemFS!
> cat readme.txt
Hello MemFS!
> ls
[readme.txt]

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🐳 Docker

Build Image

docker build -t memfs .

Run Container

docker run -p 8080:8080 memfs

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