Real Experience Migrating a Java 5 / Struts 1.3 Monolithic Application to Java 21 and Spring Boot

Migrating a monolithic Java 5 / Struts 1.3 application to Java 21 and Spring Boot used to take 14 weeks. In this episode, Yoshio Terada shares his real-world experience doing it in just two days using GitHub Copilot's app modernization tooling — including the planning, custom instructions, and verification strategies that made it work. In this episode, you'll learn: → How GitHub Copilot modernization handles a real legacy migration — Java 5 / Struts 1.3 to Java 21 / Spring Boot → Why creating a detailed migration plan and custom verification scripts is critical for AI-assisted upgrades → How to refine the AI-generated migration plan with your own instructions and domain knowledge → Why AI isn't perfect — and how planning and verification keep the migration on track → How a process that used to take 14 weeks can be completed in approximately 2 days with AI assistance 📺 This is Episode 3 of the Modernize Java Apps with AI series — a 9-part, hands-on guide to upgrading legacy Java applications using GitHub Copilot. 🔗 Series playlist: https://www.youtube.com/playlist?list=PLlrxD0HtieHhaBJWlcxGd-kTDikSD4xyD 🔗 GitHub Copilot Modernization extension: https://aka.ms/GHCPMod-Java 👤 Presented by Yoshio Terada, Java & AI Advocate, Microsoft Java #GitHubCopilot #Struts #SpringBoot #JavaMigration #LegacyJava #JavaModernization #AI #EnterpriseJava #CloudMigration