☕ OOP Using Java

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👤 Built by

public class Author {

    public static final String NAME = "RAHUL K P";

    public static final String[] ROLES = {
        "ML Engineer",
        "GenAI Engineer",
        "MSc Computer Science Student @ 2026"
    };

    public static final String LOCATION = "Kerala, India 🇮🇳";

    public static final String CERTIFICATION =
        "IBM Generative AI Engineering Professional";

    public static final String MISSION =
        "Building strong software engineering foundations for AI systems";

    public static final String CONTACT =
        "rahulkpkurup@gmail.com";
}

This repository is part of my journey toward becoming an ML Engineer, GenAI Engineer, and highly capable Software Engineer by mastering the core principles of Object-Oriented Programming, software architecture, and clean code engineering.

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🎯 What is OOP Using Java?

A production-quality Object-Oriented Programming repository built using Java, combining academic rigor with software engineering best practices.

Every module includes:

• ✅ Clean and modular Java code
• ✅ Industry-standard project structure
• ✅ OOP concepts explained with practical examples
• ✅ JUnit 5 test suites
• ✅ UML diagrams and architecture notes
• ✅ Maven build automation
• ✅ Interview-focused implementations
• ✅ Design Patterns and SOLID principles
• ✅ Documentation and learning resources

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📦 Topics Covered

📦 Category	☕ Concepts	🧪 Tests	📓 Notes
🏁 Java Basics	JVM, JDK, Variables, Methods	✅	✅
🧱 Classes & Objects	Object Creation, State, Behavior	✅	✅
🏗️ Constructors	Default, Parameterized, Copy	✅	✅
🔒 Encapsulation	Access Modifiers, Data Hiding	✅	✅
🧬 Inheritance	Single, Multilevel, Hierarchical	✅	✅
🎭 Polymorphism	Overloading, Overriding	✅	✅
🎨 Abstraction	Abstract Classes	✅	✅
🔌 Interfaces	Contracts, Implementations	✅	✅
🤝 Relationships	Association, Aggregation, Composition	✅	✅
📚 Collections	List, Set, Queue, Map	✅	✅
⚠️ Exceptions	Checked, Unchecked, Custom	✅	✅
🧮 Generics	Generic Classes & Methods	✅	✅
🧵 Multithreading	Thread, Runnable, Synchronization	✅	✅
🏛️ SOLID Principles	SRP, OCP, LSP, ISP, DIP	✅	✅
🏗️ Design Patterns	Factory, Singleton, Strategy	✅	✅
🧪 Testing	JUnit 5 & Test Design	✅	✅

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🗺️ Learning Path

🌱 BEGINNER
├── Java Basics
├── Classes & Objects
├── Constructors
├── Encapsulation
└── Packages & Access Modifiers

🌿 INTERMEDIATE
├── Inheritance
├── Polymorphism
├── Abstraction
├── Interfaces
└── Relationships Between Objects

🌳 ADVANCED
├── Collections Framework
├── Exception Handling
├── Generics
├── File Handling
└── Multithreading

🏛️ SOFTWARE DESIGN
├── SOLID Principles
├── Design Patterns
├── UML Modeling
├── Low Level Design
└── Clean Architecture

🏆 INTERVIEW READY
├── Java OOP Interview Questions
├── System Design Basics
├── Real-world Case Studies
└── Coding Challenges

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🚀 Quick Start

# 1. Clone the repository
git clone https://github.com/rahulkp-ai/oop-using-java.git
cd oop-using-java

# 2. Auto setup (recommended)
chmod +x setup.sh && ./setup.sh

# 3. Build project
mvn clean install

# 4. Run all tests
mvn test

# 5. Generate reports
mvn site

# 6. Run examples
mvn exec:java

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📁 Repository Structure

oop-using-java/
├── src/
│   ├── basics/                     # Java fundamentals
│   ├── classes_objects/            # Classes and Objects
│   ├── constructors/               # Constructor examples
│   ├── encapsulation/              # Data hiding
│   ├── inheritance/                # Inheritance hierarchy
│   ├── polymorphism/               # Runtime & compile-time polymorphism
│   ├── abstraction/                # Abstract classes
│   ├── interfaces/                 # Interface contracts
│   ├── relationships/              # Composition, Aggregation, Association
│   ├── collections/                # Collections Framework
│   ├── exception_handling/         # Exception management
│   ├── generics/                   # Generic programming
│   ├── multithreading/             # Concurrent programming
│   ├── solid_principles/           # SOLID implementations
│   ├── design_patterns/            # Factory, Strategy, Singleton etc.
│   ├── mini_projects/              # Real-world projects
│   └── cli/                        # Optional CLI applications
│
├── notebooks/                      # Interactive learning notebooks
│   ├── 01_java_basics.ipynb
│   ├── 02_classes_objects.ipynb
│   ├── 03_encapsulation.ipynb
│   ├── 04_inheritance.ipynb
│   ├── 05_polymorphism.ipynb
│   ├── 06_abstraction.ipynb
│   ├── 07_interfaces.ipynb
│   ├── 08_collections.ipynb
│   ├── 09_multithreading.ipynb
│   └── 10_design_patterns.ipynb
│
├── tests/
│   ├── unit/                       # JUnit tests
│   ├── integration/                # Integration tests
│   └── performance/                # Optional benchmarks
│
├── problems/                       # Practice problems
│   ├── beginner/
│   ├── intermediate/
│   └── advanced/
│
├── solutions/                      # Complete solutions
├── diagrams/                       # UML diagrams
├── docs/                           # Documentation
├── interview_prep/                 # Interview resources
├── datasets/                       # Practice datasets
├── assets/                         # Images & banners
├── .github/
│   └── workflows/                  # CI/CD workflows
│
├── pom.xml
├── Makefile
├── setup.sh
└── README.md

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📊 Repository Statistics

Category	Count
☕ Java Source Files	60+
📓 Jupyter Notebooks	27
🧪 JUnit Test Files	15+
📋 Problem Sets	15
✅ Solution Modules	9
📚 Documentation Files	16+
📐 UML Diagrams	10+
🗄️ Datasets	4
🤖 CI/CD Workflows	3

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💼 Interview Preparation

Resource	Description
docs/oop_cheatsheet.md	Quick OOP revision guide
docs/solid_principles.md	SOLID principles with examples
docs/design_patterns.md	Most asked design patterns
interview_prep/java_oop_questions.md	100+ Java interview questions
interview_prep/system_design_basics.md	Beginner-friendly system design
interview_prep/backend_roadmap.md	Java backend roadmap

This repository helps prepare for:

• 🏢 Software Engineering Interviews
• ☕ Java Backend Developer Roles
• 🎓 MSc / MCA Viva Examinations
• 📝 Coding Assessments
• 🏗️ Low-Level Design Discussions

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🧪 Running Tests

# Run all tests
mvn test

# Run a specific test
mvn -Dtest=StudentTest test

# Generate coverage reports
mvn jacoco:report

# Run integration tests
mvn verify

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🤝 Contributing

This is an open learning project. Contributions are welcome!

# Create feature branch
git checkout -b feature/new-concept

# Write code and tests
mvn test

# Commit changes
git commit -m "Add: Strategy Pattern Example"

# Push branch
git push origin feature/new-concept

See CONTRIBUTING.md for full contribution guidelines.

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📜 License

MIT License — see LICENSE.

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Built by RAHUL K P — ML Engineer · GenAI Engineer · MSc CS @ 2026

⭐ Star this repository if it helped your Java learning journey — and connect on LinkedIn!