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GitHub - kousen/java_latest: Samples for Java features from Java 8 through 25

Modern Java: From 8 to 25 and Beyond

Comprehensive examples and demonstrations of Java features from Java 8 through Java 25, showcasing the evolution of the Java language and platform.

🚀 What's Included

  • Practical Code Examples - Real-world demonstrations of modern Java features
  • Comprehensive Test Suite - 160+ tests covering all major functionality
  • Workshop Presentation - Complete slide deck covering Java evolution (slides.md)
  • Java Tier List Presentation - Feature ranking and discussion format (slides-java-tier-list.md)
  • Workshop Exercises - Hands-on labs with complete solutions (workshop-exercises.md)
  • Data-Oriented Programming - Examples of records, sealed classes, and pattern matching working together

🎯 Key Features Covered

Java 8 - The Functional Revolution

  • Lambda expressions and method references
  • Stream API with advanced collectors
  • Optional for null safety
  • Default and static methods in interfaces
  • CompletableFuture for async programming

Java 9-11 - Platform Maturity

  • JShell (Java REPL)
  • Collection factory methods (List.of(), Map.of())
  • Local variable type inference (var)
  • HTTP Client API
  • String enhancements (isBlank(), strip(), repeat())

Java 12-17 - Language Evolution

  • Text blocks for multi-line strings
  • Records for immutable data classes
  • Pattern matching for instanceof
  • Switch expressions with yield
  • Sealed classes for controlled inheritance

Java 18-21 - Modern Features

  • Simple web server (jwebserver)
  • Virtual threads for scalable concurrency
  • Sequenced collections
  • Pattern matching in switch
  • Enhanced pattern matching with guards

Java 22-25 - Latest LTS

  • Unnamed variables with _ (Java 22)
  • Stream Gatherers (Java 24)
  • Scoped Values (finalized in Java 25 LTS)
  • Module Import Declarations (Java 25)
  • Flexible Constructor Bodies (Java 25)
  • Primitive types in patterns (3rd preview in Java 25)
  • Structured Concurrency (5th preview in Java 25)

🛠️ Build Requirements

  • Java 25 LTS - Latest Long-Term Support release with preview features enabled
  • Gradle 9.1.0+ - Modern build tooling with Java 25 support
  • JUnit 5.13.3 - Modern testing framework
  • SonarCloud - Code quality analysis configured for educational code standards

🏃‍♂️ Quick Start

# Clone the repository
git clone https://github.com/kousen/java_latest.git
cd java_latest

# Run all tests
./gradlew test

# Run a specific example
./gradlew run

# Generate code coverage report
./gradlew jacocoTestReport

📊 Running the Presentation

The repository includes a comprehensive Slidev presentation:

# Install dependencies for PDF export
npm install

# Start the presentation
npx slidev slides.md

# Export to PDF
npx slidev export slides.md --format pdf

🎓 Learning Path

For Self-Study

  1. Start with Java 8 - ProcessDictionaryV2.java showcases functional programming
  2. Explore Records - See Person.java, Customer.java for data classes
  3. Pattern Matching - Check UseShapes.java for modern control flow
  4. Virtual Threads - VirtualThreadsDemo.java for scalable concurrency
  5. Data-Oriented Programming - Combine records, sealed classes, and pattern matching

For Workshops

  1. Review the slides - slides.md provides comprehensive coverage
  2. Work through exercises - workshop-exercises.md contains hands-on labs
  3. Check solutions - Complete implementations in exercises.solutions package
  4. Practice with examples - Explore the main codebase for real-world patterns

📚 Key Examples

  • ProcessDictionaryV2 - Comprehensive Stream API showcase
  • astro package - HTTP Client with Result pattern (sealed interfaces)
  • shapes package - Sealed classes with pattern matching
  • VirtualThreadsDemo - Modern concurrency patterns

🧪 Testing

# Run all tests
./gradlew test

# Run tests for a specific package
./gradlew test --tests "*interfaces*"

# Run workshop solution tests
./gradlew test --tests "exercises.solutions.*"

# Run with coverage
./gradlew test jacocoTestReport

📈 Code Coverage

JaCoCo reports are generated in build/reports/jacoco/test/html/index.html

📖 Additional Resources

👨‍💻 Author

Kenneth Kousen

This repository is actively maintained and updated with the latest Java features as they become available.