Skip to content

exercise-1-java.md

Latest commit

 

History

History
138 lines (91 loc) · 4.28 KB

exercise-1-java.md

File metadata and controls

138 lines (91 loc) · 4.28 KB

Exercise 1: Java Tournament Service Modernization

Duration: 30 minutes
Difficulty: ⭐⭐⭐ Intermediate
Prerequisites: Java 17+, Maven 3.8+, GitHub Copilot enabled

The Challenge

The Tournament Service is the backbone of Game Arena Legends. It handles tournament creation, player registration, bracket generation, and match scheduling. Built in 2018 with Spring Boot 2.7, it's showing its age:

  • Blocking I/O operations causing slow response times during peak traffic
  • Outdated dependencies with known security vulnerabilities
  • Missing observability for production debugging
  • No support for reactive programming patterns

Your mission: Modernize this service to handle 10x the current traffic using Spring Boot 3.2 and reactive patterns.

Getting Started

Clone the repository:

git clone https://github.com/CanarysPlayground/app-modernization-workshop.git
cd app-modernization-workshop
cd legacy-code/java-tournament-service

Verify your environment:

java -version
mvn -version

Ensure you have:

Build the legacy code:

mvn clean install
mvn spring-boot:run

Test the API in another terminal:

curl http://localhost:8080/api/tournaments

Modernization Workflow

Step 1: Use Copilot for Assessment (4 minutes)

  1. Install GitHub Copilot App Modernization - Java Upgrade

    Open extension and search for "GitHub Copilot App Modernization - Java Upgrade". Install if you haven't already.

    Install Extensions

  2. Select the Right Model for Assessment:

    Click the Copilot icon → Model Selector → Choose:

    • GPT-4 for comprehensive analysis (recommended for assessment)
    • Claude 4.5 Sonnet for alternative perspective

  3. Use Copilot Chat local agent - ask agent for Assessment:

    Open Copilot Chat (Ctrl+Alt+I or Cmd+Alt+I) and ask:

    Analyze this Spring Boot project. What version is it using? What needs to be upgraded for Spring Boot 3.2? Identify deprecated dependencies and breaking changes.

    The analysis will cover:

    • Current framework versions
    • Deprecated dependencies
    • Breaking changes (javax→jakarta)
    • Reactive patterns recommendations
    • Migration steps

  4. Select Custom agent AppModernization

Custom agent

Step 2: Upgrade and Verify (10 minutes)

Upgrade the application:

Open pom.xml and use Copilot to upgrade:

"Migrate to Spring Boot 3.2.0 with Java 17, converting from blocking (Web/JPA) to fully reactive (WebFlux/R2DBC)"

Expected Results:

Copilot automatically transforms:

  • Spring Boot 2.3 → 3.2, Java 11 → 17
  • javax.* → jakarta.*
  • Controllers/Services/Repositories → Reactive (Flux/Mono)
  • JpaRepository → ReactiveCrudRepository

Key Takeaways

Single comprehensive prompt triggers complete stack modernization
@workspace analyzes entire project structure before changes
Spring Boot 3.2 requires Java 17+ and jakarta namespace
Reactive patterns: Flux (0..N), Mono (0..1) for non-blocking I/O

Additional Resources

Next Steps

Congratulations! You've modernized the Tournament Service.

Exercise 2: CVE Detection & Security Hardening →

  • Learn Copilot CLI automation with custom agents
  • Detect and fix CVEs using MCP server tools
  • Generate security tests with AI
  • Duration: 25 minutes

Achievement Unlocked: Java Modernization Expert!