Java Crash Course
Java is the workhorse of the software industry. From massive enterprise backends and Android apps to big data processing and high-frequency trading, Java runs the world.This crash course is designed to take you from “Hello World” to understanding the JVM, concurrency, and modern Java (17/21) features.
Why Java?
Java has consistently been one of the top languages for 25+ years.Write Once, Run Anywhere
The JVM (Java Virtual Machine) allows your code to run on any device, from servers to toasters.
Enterprise Grade
Strict type safety, massive ecosystem, and backward compatibility make it the #1 choice for large systems.
Multithreading
Built-in support for concurrency makes building scalable, high-performance applications easier.
Modern Evolution
With a 6-month release cycle, Java is evolving fast: Records, Pattern Matching, Virtual Threads, and more.
Course Roadmap
We will peel back the layers of abstraction to understand how Java really works.1
Fundamentals
Understand the JVM, bytecode, types, and control flow.
Start Learning
2
Object-Oriented Programming
Classes, interfaces, inheritance, and polymorphism.
Explore OOP
3
Collections Framework
Lists, Maps, Sets, and the Stream API.
Master Collections
4
Concurrency
Threads, Executors, and CompletableFutures.
Go Parallel
5
Modern Java
Lambdas, Streams, Records, and Pattern Matching (Java 8 to 21).
Go Modern
Prerequisites
- Basic programming knowledge.
- JDK 17 or higher installed (
java -version). - An IDE (IntelliJ IDEA is highly recommended, VS Code is also good).
The Java Philosophy
“Java is C++ without the guns, knives, and clubs.” — James GoslingJava manages memory for you (Garbage Collection), prevents buffer overflows (Array Bounds Checking), and enforces type safety. It trades some raw control for safety and productivity.