Java Tutorial

Java Tutorial For Developers Switching To Java

A Cloudflare Pages-ready course website with two-hour learner workbooks, full lesson guidance, and one generated page for every Java function in the tutorial repository.

Lesson 1: Advanced OOP

Records, classes, enums, sealed interfaces, generics, pricing rules, validation, sorting, grouping, and domain invariants.

63 generated function pages

workbook instructor notes edge cases

Lesson 2: Decorator Usage

Object decorators, Java I/O decorators, functional wrappers, wrapper order, side effects, blocklists, truncation, counting, and composition.

51 generated function pages

workbook instructor notes edge cases

Lesson 3: Multi-Threading

Executors, futures, CompletableFuture, virtual threads, atomic counters, deterministic aggregation, top-N ranking, and ordered parallel results.

46 generated function pages

workbook instructor notes edge cases

Lesson 4: Toy Edge Detect Library

Image matrices, grayscale conversion, convolution, Sobel edge detection, pixel math, normalization, clamped sampling, and PNG output.

67 generated function pages

workbook instructor notes edge cases

Lesson 5: Java @ Annotations

All major Java @ use cases: built-ins, custom annotations, meta-annotations, repeatable annotations, type-use annotations, package and record targets, decorator-style metadata, getter/setter metadata, and reflection.

106 generated function pages

workbook instructor notes edge cases

Lesson 6: Spring Boot Hello World

A first Spring Boot web app with Maven, @SpringBootApplication, @RestController, query parameters, JSON POST requests, configuration properties, service validation, error handling, and tests.

45 generated function pages

workbook instructor notes edge cases

Use The Course

Run The Java Labs

scripts/test.sh
scripts/verify_answers.sh

Deploy The Website

cd cloudflare-pages
npm run build

Cloudflare Pages output directory: dist.

Function Coverage

The build detected 378 Java functions, methods, constructors, compact record constructors, and interface methods.

Open the function index.

Course Docs