☕ Complete Java learning resource — structured notes, 100+ interview questions, coding problems, handwritten notes, practice sheets & cheatsheets. Perfect for beginners, job seekers & DSA prep. Free & open-source.
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This repository is a one-stop Java resource kit — whether you're a complete beginner, preparing for a job interview, or grinding DSA problems, there's something here for you.
| Folder | Contents | Best For |
|---|---|---|
📝 notes/ |
Clean, structured Java theory notes | Beginners & revision |
❓ interview-questions/ |
Top Java interview Q&A (fresher to senior) | Job prep |
💻 coding-questions/ |
Solved Java coding problems with explanation | DSA practice |
✍️ handwritten-notes/ |
Handwritten notes scanned for quick revision | Visual learners |
📋 practice-sheets/ |
Topic-wise practice sheets with problems | Daily practice |
📄 cheatsheets/ |
Quick reference cheatsheets for syntax & concepts | Fast revision |
🔰 Core Java Fundamentals
- Data types, Variables & Operators
- Control flow (if/else, switch, loops)
- Arrays & Strings
- Methods & Recursion
- Input/Output (Scanner, BufferedReader)
🧱 Object-Oriented Programming (OOP)
- Classes & Objects
- Constructors &
thiskeyword - Inheritance & Method Overriding
- Polymorphism (compile-time & runtime)
- Abstraction & Interfaces
- Encapsulation & Access Modifiers
static,final,superkeywords
⚙️ Advanced Java
- Collections Framework (List, Set, Map, Queue)
- Generics
- Exception Handling (try/catch/finally, custom exceptions)
- Multithreading & Concurrency
- Java 8+ Features (Streams, Lambda, Optional, Functional Interfaces)
- File I/O & Serialization
🧠 Data Structures & Algorithms (DSA)
- Arrays, Linked Lists, Stacks, Queues
- Trees (Binary Tree, BST, AVL)
- Graphs (BFS, DFS, Dijkstra)
- Sorting & Searching Algorithms
- Dynamic Programming
- Recursion & Backtracking
🎯 Interview Preparation
- Top 100 Java interview questions (with answers)
- Tricky output-based questions
- OOP scenario-based questions
- Java 8 interview questions
- Collections & multithreading interview Qs
- HR + Technical round tips
# Clone the repo to your local machine git clone https://github.com/AdityaChouhan01/java-resources.git # Navigate into it cd java-resources # Open in VS Code code .
Or just browse the folders directly on GitHub — no setup needed!
- 🎓 Students learning Java for the first time
- 💼 Job seekers preparing for technical interviews (fresher / 1–3 years exp)
- 🧑💻 Developers who want a quick cheatsheet or revision material
- 📚 Self-learners following online courses who want supplementary notes
- 🏆 Competitive programmers grinding DSA in Java
- ✅ Handwritten + typed notes — best of both worlds
- ✅ Topic-wise organized — no hunting around
- ✅ Interview-ready Q&A — real questions asked in companies
- ✅ Cheatsheets — print and stick on your wall
- ✅ Free forever — open-source, no paywalls
- ✅ Regularly updated — new content added as I learn
java-resources/
│
├── 📝 notes/
│ ├── 01-java-basics.md
│ ├── 02-oop-concepts.md
│ ├── 03-collections.md
│ ├── 04-java8-features.md
│ └── 05-multithreading.md
│
├── ❓ interview-questions/
│ ├── core-java-interview-qs.md
│ ├── oop-interview-qs.md
│ ├── java8-interview-qs.md
│ └── collections-interview-qs.md
│
├── 💻 coding-questions/
│ ├── arrays/
│ ├── strings/
│ ├── linked-list/
│ ├── trees/
│ └── dynamic-programming/
│
├── ✍️ handwritten-notes/
│ ├── oop-diagrams.pdf
│ └── dsa-handwritten.pdf
│
├── 📋 practice-sheets/
│ ├── week-01-basics.md
│ ├── week-02-oop.md
│ └── week-03-dsa.md
│
└── 📄 cheatsheets/
├── java-syntax-cheatsheet.md
├── collections-cheatsheet.md
└── java8-cheatsheet.md
⚠️ Update the folder structure above to match your actual files before pushing!
Found a mistake? Want to add more questions or notes? Contributions are welcome!
- Fork this repo
- Create a branch:
git checkout -b add-my-notes - Commit your changes:
git commit -m "Add: topic-wise recursion notes" - Push:
git push origin add-my-notes - Open a Pull Request
If this helped you, let me know! I'm always open to feedback, suggestions, or just a hello.
This repository is licensed under the MIT License — free to use, share, and modify with credit.
If this repo saved you time, give it a ⭐ — it costs nothing and means everything!
Made with ☕ and late nights by Aditya Chouhan