Learn Java From Scratch: The Complete Free Course (2026 Roadmap)

Welcome to GyaanPost's complete Java course — a free, beginner-friendly path that takes you from writing your very first line of code all the way to building real applications. There are no prerequisites. If you can use a computer, you can start here today.

This is the page to bookmark. It's the map for the whole journey: every lesson, in the right order, each one building on the last. Work through it top to bottom and you'll never wonder "what should I learn next?" — just follow the trail.

Why learn Java?

Java is one of the most widely-used programming languages in the world, and it has been for over two decades. Here's why it's a fantastic first language to learn:

• It's everywhere — Android apps, banking systems, e-commerce backends, and huge enterprise software all run on Java. Learning it opens a lot of doors.
• It's in demand — "Java Developer" is one of the most consistently hired roles in the software industry, especially in India.
• It teaches good habits — Java's structure forces you to think clearly about types and organisation, which makes you a stronger programmer in any language later.
• "Write once, run anywhere" — the same Java program runs on Windows, Mac, and Linux without changes.

A little honesty from experience: this whole website — GyaanPost — is itself built with Java and Spring Boot. So the things you'll learn here aren't academic trivia; they're the exact tools I use to run a real, live application. That's the perspective I'll bring to every lesson.

Phase 1 — Core Java (the foundation)

This is where everyone starts. By the end of Phase 1 you'll understand variables, logic, loops, methods, and object-oriented programming — the bedrock of all Java. Take these in order.

Level 1 — Your first steps

1. What is Java? How It Really Works
2. Install Java & Run Your First Program
3. Java Syntax Basics: Your First Program Explained
4. Variables and Data Types
5. Operators in Java Explained
6. Input and Output (Scanner)
7. Decisions: if, else & switch
8. Loops: for, while & do-while
9. Methods (Functions) in Java
10. Arrays in Java
11. Strings in Java

Level 2 — Object-Oriented Programming (OOP)

OOP is the heart of Java. This is what turns you from someone who writes scripts into someone who designs real software.

12. Classes and Objects
13. Constructors
14. Encapsulation
15. Inheritance
16. Polymorphism
17. Abstraction & Interfaces
18. Packages & the static keyword
19. this, super & final

Level 3 — Core Java in depth

20. Exception Handling
21. The Collections Framework
22. List, Set & Map
23. Generics
24. Enums & Wrapper Classes
25. equals() and hashCode()
26. Immutability

Level 4 — Advanced Java

27. Lambdas & Functional Interfaces
28. The Streams API
29. Optional
30. Multithreading
31. File I/O
32. Date & Time API
33. JVM, Memory & Garbage Collection

What comes after Core Java?

Once you're comfortable with the fundamentals above, the path continues into two powerful areas. These have their own dedicated roadmaps (linked here so you know what's ahead):

• Data Structures & Algorithms (DSA) — the problem-solving skills that get you through coding interviews. See the DSA in Java roadmap →
• Spring Boot — the framework used to build real backend applications and REST APIs (the same one this website runs on). See the Spring Boot roadmap →

Ready? Let's begin.

Everything starts with one simple question: what actually is this language you're about to learn? Let's answer it properly.

Start here → Lesson 1: What is Java?