Java Engineering Masterclass 🚀

An interactive, production-grade React application for mastering advanced Java/JVM concepts through visual simulations and deep-dive theory.

🎯 Features

Interactive Simulators

Module	Description	Visualization
Garbage Collection	Eden, Survivor, Old Gen memory pools	Object allocation & GC cycles
Concurrency	Monitor locks, Entry/Wait sets	Thread state transitions
JIT Compilation	Tiered compilation (Interpreted → C1 → C2)	Profiling & optimization
Java Memory Model	CPU caches, Main Memory, Volatile	Cache coherence & visibility
Static vs Instance	Metaspace vs Heap memory layout	Static field sharing

Educational Theory

Each module includes comprehensive "Engineer's Guide" content covering:

• Under-the-hood JVM internals
• Best practices and anti-patterns
• Thread safety considerations
• Performance implications

🏗️ Architecture

Built following SOLID principles with a modular, scalable architecture:

src/
├── components/           # Reusable UI components
│   ├── Layout/          # Header, Layout wrapper
│   ├── UI/              # Button, Console, MemoryBlock
│   └── Hub/             # Module selection grid
├── features/            # Feature modules (one per topic)
│   ├── gc/              # Garbage Collection
│   ├── threads/         # Concurrency
│   ├── jit/             # JIT Compilation
│   ├── jmm/             # Java Memory Model
│   └── static/          # Static vs Instance
├── hooks/               # Custom React hooks (simulation logic)
├── contexts/            # React Context providers
├── types/               # TypeScript type definitions
└── App.tsx              # Root application component

🚀 Getting Started

Prerequisites

• Node.js 18+
• npm or yarn

Installation

# Clone the repository
git clone https://github.com/pramithamj/java-masterclass.git
cd java-masterclass

# Install dependencies
npm install

# Start development server
npm run dev

Open http://localhost:5173 in your browser.

Build for Production

npm run build
npm run preview    # Preview production build locally

🌐 Deployment

GitHub Pages

The app is configured for GitHub Pages deployment:

1. Build the project: npm run build
2. Push to your repository
3. Enable GitHub Pages in repository settings (deploy from gh-pages branch or /docs folder)

Note: The base path in vite.config.ts must match your repository name.

📚 Module Details

Garbage Collection Simulator

Visualize the Generational Hypothesis in action:

• Eden Space: Where new objects are allocated
• Survivor Space: Objects that survive Minor GC
• Old Generation: Long-lived objects (tenured)
• Trigger Minor GC and Full GC to see object lifecycle

Concurrency Simulator

Understand Java's Monitor Lock mechanism:

• See threads competing for synchronized blocks
• Watch Entry Set (blocked) and Running states
• Visualize lock acquisition and release

JIT Compilation Simulator

Watch code get "hot" and tiered compilation kick in:

• Interpreted: Initial slow execution
• C1 Compiler: Quick compilation, basic optimizations
• C2 Compiler: Aggressive optimization (inlining, escape analysis)

Java Memory Model Lab

Understand visibility and happens-before:

• CPU L1 caches vs Main Memory
• Volatile writes flush to memory
• Non-volatile reads may see stale data

Static vs Instance Lab

Visualize where static and instance members live:

• Metaspace: Class-level static fields (shared)
• Heap: Per-instance fields (unique per object)
• See how static changes affect ALL instances

🛠️ Technology Stack

• React 19 - UI framework with hooks
• TypeScript 5.9 - Type safety
• Vite 7 - Fast build tool with HMR
• CSS Modules - Scoped styling
• ESLint - Code quality

📝 Design Principles

1. Single Responsibility (SRP): Each component/hook has one clear purpose
2. Open/Closed (OCP): Easy to add new modules without modifying core
3. Dependency Inversion (DIP): Contexts provide injectable dependencies
4. Interface Segregation (ISP): Small, focused type interfaces

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Inspired by the need for better JVM education tools
• Built with modern React best practices
• Designed for developers learning advanced Java concepts

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