A didactic, vanilla Java project (no frameworks) that showcases, in a practical way, the major evolutions of the language from Java 8 to Java 26.

Instead of toy snippets, the features are put to work inside a realistic — but deliberately bounded — iGaming / sports-betting domain: odds, stakes, betting tickets and the calculation of potential winnings.

Why this exists: most "what's new in Java X" resources are isolated one-liners. This repo is the opposite: one coherent domain, built with modern Java only, where every major language feature is used where it naturally fits and is marked with a comment explaining which version introduced it and what benefit it brings.

• Modern Java only. No legacy / before-after code. The idiomatic modern form is the only form shown. Each major feature carries a didactic comment.
• Vanilla. No Spring, no framework. Logging via the JDK's System.Logger (zero dependencies). Third-party libraries are allowed only when they add real value.
• Correct by domain. Money is modeled with BigDecimal, not double, to avoid floating-point rounding errors — as any real financial system must.
• Verifiable. Every type is covered by JUnit 5 tests; each module will also expose a runnable main demo.

Features are introduced progressively, as the domain needs them.

Minor, isolated API tweaks are deliberately omitted — the focus is the major language evolutions.

• JDK 26 (the Gradle toolchain will provision/validate it).
• No global Gradle install needed — use the bundled wrapper (./gradlew).

# Run the tests
./gradlew test

# Run the application entry point
./gradlew run

Single Gradle module, one package per domain area.

src/
├── main/java/com/adrianodiaz/igamingjavaevolution/
│   ├── IgamingJavaEvolutionApplication.java   # entry point
│   ├── shared/
│   │   └── Messages.java                       # centralized string constants
│   └── betengine/                              # first domain module
│       ├── Odds.java                           # record + validation (BigDecimal)
│       └── Stake.java                          # record + validation (BigDecimal)
└── test/java/com/adrianodiaz/igamingjavaevolution/
    └── betengine/
        ├── OddsTest.java
        └── StakeTest.java

docs/
└── design/
    └── 2026-07-23-bet-engine-design.md         # full design of the bet-engine module

The project grows module by module. The first module, bet-engine, is where the core value types and the winnings logic live.

bet-engine — in progress

• Odds — decimal odds value object (record, compact-constructor validation)
• Stake — wagered amount value object (record, BigDecimal)
• Selection — a pick composing Odds
• Bet — sealed interface: SingleBet, AccumulatorBet, SystemBet
• TicketStatus — sealed interface: Placed, Settled, Cancelled
• BettingTicket — aggregate record
• WinningsCalculator — switch pattern matching + record patterns
• BetEngineDemo — runnable main with a text-block receipt

Planned next

• Web playground (JDK com.sun.net.httpserver.HttpServer + plain HTML/JS, no framework) to exercise the engine from a browser.
• Further domain modules exploring more language features.

See docs/design/2026-07-23-bet-engine-design.md for the detailed design and step-by-step build guide.

Educational project — free to read, learn from, and adapt.