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

Microsoft Developer

A developer shares their real-world experience using GitHub Copilot to modernize a legacy Java 5 / Struts 1.3 monolithic application to Java 21 and Spring Boot. The migration, which would have taken ~14 weeks manually, was completed in about 2 days with AI assistance. Key takeaways include the importance of creating a detailed migration plan, using custom verification skills to catch AI mistakes, and adding custom instructions to guide the AI agent through the migration steps.

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