☕ Core Java Concepts Learning Repository

This repository is a comprehensive collection of hands-on examples and explanations covering all Core Java concepts — from basic syntax and OOP principles to advanced topics like multithreading, exception handling, collections, and file handling.

The goal of this repository is to provide clear, practical, and example-driven learning material that helps you build a strong foundation in Java programming and prepare for frameworks like Spring or for technical interviews.

🎯 Objectives

Understand Java fundamentals (data types, control structures, operators)

Master Object-Oriented Programming (OOP) principles

Learn Exception Handling and custom exceptions

Work with Collections Framework (List, Set, Map, etc.)

Explore File Handling and I/O Streams

Understand Multithreading and thread synchronization

Learn Interfaces, Abstract Classes, and Inner Classes

Understand Packages, Access Modifiers, and Static Members

Build small Java programs to reinforce each topic

🧩 Topics Covered

1. Introduction to Java JDK, JRE, JVM, Compilation process
2. Data Types & Variables Primitive types, literals, and memory usage
3. Control Statements if-else, loops, switch, break, continue
4. Arrays & Strings Operations on arrays and string manipulation
5. Object-Oriented Programming (OOP) Classes, objects, methods, encapsulation, inheritance, polymorphism, abstraction
6. Constructors & Static Members Default, parameterized constructors, static methods/variables
7. Interfaces & Abstract Classes Implementing abstraction and multiple inheritance
8. Exception Handling try-catch-finally, throws, throw, custom exceptions
9. Collections Framework ArrayList, HashSet, HashMap, Iterator, Comparator
10. File Handling Reading/Writing files using FileReader, BufferedReader, FileWriter
11. Multithreading Thread class, Runnable interface, synchronization
12. Wrapper Classes & Autoboxing Conversion between primitives and objects
13. Inner & Anonymous Classes Understanding scopes and closures
14. Java 8 Features (Intro) Lambda expressions, functional interfaces, streams