Learn Java 25
A two-day course on modern Java, based on Java 25 (LTS). No Java experience needed. Programming experience in any language helps.
Everything here runs on a plain JDK 25 install — no build tool, no framework, no boilerplate.
Why Java 25?
Java 25 is the current LTS release (September 2025), the successor to Java 21.
It adds compact source files, java.lang.IO, module imports, flexible constructor bodies
and scoped values.
Course outline
| Introduction | Setup · JShell |
| Day 1 | types, methods, collections, boolean logic, control flow, files, HTTP |
| Day 2 | streams, OOP, exceptions, modules, CLI tools, virtual threads, tests |
| Appendix | Cheat sheet · Resources |
Each chapter ends with ★ Exercises. Type the samples instead of pasting them — reading compiler errors is how you learn fastest.
What you need
- A JDK 25 build (Temurin, Corretto, Oracle OpenJDK)
- VS Code with the Java extension pack, or IntelliJ IDEA Community
- A terminal — every sample runs with
javaandjshell