This repository is a structured, day-by-day study guide designed to help learners
build a strong foundation in Java, progressing from basic concepts to advanced
topics and real-world backend development practices.
Each day includes:
- Concept explanation (Markdown)
- Real-life examples
- Simple pseudo code
- Java implementation files
Goal:
To provide a clear, practical, and industry-relevant learning path for mastering Java.
Day 1 : Introduction to Java and OOP Concepts
Day 2 : Variables, Data Types, and Operators
Day 3 : Control Flow (if-else, switch, loops)
Day 4 : Methods and Functions
Day 5 : Arrays (1D and 2D)
Day 6 : Strings and String Handling
Day 7 : Memory Basics (Stack vs Heap, Pass by Value)
Phase 2: Core OOP and Java Essentials
Day 8 : Classes and Objects Deep Dive
Day 9 : Constructors in Java
Day 10 : Encapsulation
Day 11 : Inheritance
Day 12 : Polymorphism (Compile-time and Runtime)
Day 13 : Abstraction (Abstract Class and Interface)
Day 14 : Access Modifiers and Packages
Phase 3: Intermediate Java
Day 15 : Static Keyword (Variable, Method, Block)
Day 16 : Final Keyword
Day 17 : This and Super Keywords
Day 18 : Exception Handling (try-catch, custom exceptions)
Day 19 : Collections Framework - List
Day 20 : Collections Framework - Set and Map
Day 21 : Generics
Phase 4: Advanced Core Java
Day 22 : File Handling (I/O Streams)
Day 23 : Serialization and Deserialization
Day 24 : Multithreading Basics
Day 25 : Thread Lifecycle and Synchronization
Day 26 : Executor Framework (Thread Pools)
Day 27 : Lambda Expressions
Day 28 : Streams API
Phase 5: Advanced Concepts and Design
Day 29 : Java Memory Model and Garbage Collection
Day 30 : JVM, JDK, and JRE Deep Dive
Day 31 : SOLID Design Principles
Day 32 : Design Patterns (Singleton, Factory, Strategy)
Day 33 : Logging in Java (SLF4J basics)
Day 34 : Java 8 and Above Features Recap
Phase 6: Backend Development Essentials
Day 35 : Introduction to Spring Boot
Day 36 : REST API Development (Controller and Service Layers)
Day 37 : Dependency Injection
Day 38 : Spring Data JPA Basics
Day 39 : Exception Handling in REST APIs
Day 40 : Basic Project Structure and Clean Architecture
java-study-guide/
│
├── README.md
│
├── Day1/
│ ├── concepts.md
│ ├── Example1.java
│ ├── Example2.java
│
├── Day2/
│ ├── concepts.md
│ ├── Example1.java
│
...
- Focus on understanding concepts, not memorization
- Use real-world analogies for clarity
- Reinforce learning through hands-on coding
- Follow a structured progression from basics to advanced topics
Follow the study plan sequentially.
Each day builds on previous concepts, so completing topics in order
is recommended for maximum understanding.
Name : Tejas Kumar S
Role : Senior Software Engineer
This repository is designed to evolve.
Future improvements may include:
- Enhanced examples
- Additional edge cases
- Advanced real-world scenarios