Java 25 In Action

Companion code for the "From Java 8 to Java 25: The Modern Java Engineering Series"

A comprehensive multi-module project demonstrating every major feature from Java 8 to Java 25.

Quick Start

git clone https://github.com/techishthoughts-org/mordern-java-revision.git
cd mordern-java-revision
./gradlew build
./gradlew test

Requirements: Java 21+ (download) | Gradle 8.x (wrapper included)

Modules

#	Module	Topics	Tests
01	evolution-overview	Java 8 vs 25 comparisons, mindset shift	29
02	modern-syntax	Records, patterns, var, text blocks	46
03	data-oriented-programming	DOP vs OOP, sealed types	37
04	functional-patterns	Strategy, Decorator, Chain of Responsibility	92
05	performance-myths	JIT optimizations, benchmarks	106
06	gc-memory	ZGC, compact headers, object sizing	94
07	lombok-migration	Lombok to native Java migration	89
08	concurrency	Virtual Threads, Structured Concurrency	21
09	stream-gatherers	Custom intermediate operations	39
10	cloud-native	Containers, health probes, HTTP server	65
11	iot-edge	IoT sensors, edge computing patterns	91
12	ai-integration	LangChain4j, Vector API, RAG	16
13	migration-blueprint	Full migration case study	89

Total: 814 tests

Key Features

Project Amber (Language)

• Records - Immutable data carriers
• Sealed Classes - Closed type hierarchies
• Pattern Matching - Type-safe switch with deconstruction
• Text Blocks - Multi-line strings
• var - Local type inference

Project Loom (Concurrency)

• Virtual Threads - Lightweight threads for I/O
• Structured Concurrency - Task lifecycle management
• Scoped Values - Safe context propagation

Performance

• Stream Gatherers - Custom stream operations
• Vector API - SIMD operations
• Generational ZGC - Sub-millisecond pauses
• Compact Headers - Reduced object overhead

JEPs Covered

JEP	Feature	Version
286	var	10
378	Text Blocks	15
395	Records	16
409	Sealed Classes	17
441	Pattern Matching for switch	21
444	Virtual Threads	21
473	Stream Gatherers	23+
480	Structured Concurrency	21+
506	Scoped Values	21+
519	Compact Object Headers	25

Project Structure

java-25-in-action/
├── build.gradle.kts
├── settings.gradle.kts
├── common/
├── 01-evolution-overview/
├── 02-modern-syntax/
├── ...
└── 13-migration-blueprint/

Running Modules

# Run specific module
./gradlew :08-concurrency:run
./gradlew :09-stream-gatherers:run

# Run with preview features (configured automatically)
./gradlew build

Contributing

1. Fork the repository
2. Create a feature branch
3. Submit a pull request

License

MIT License - see LICENSE

References

Official

• OpenJDK
• Project Amber
• Project Loom

Books & Docs

• Data-Oriented Programming - Yehonathan Sharvit
• LangChain4j Documentation

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