Claude Code: Upgrade Spring Boot 2 to 4 and Java 11 to 25

About this course

This course contains the use of artificial intelligence.

Spring Boot 2.7 lost its free support in 2023, and since June 2026 the whole 3.x line is out of open-source support as well. If your team still runs services on these versions, the upgrade is on the roadmap whether you like it or not. It is also exactly the kind of long, repetitive, test-driven work where an AI coding agent can save weeks, as long as it is set up so it cannot quietly break your API.In this course you upgrade one realistic legacy service, ShipTrack, a parcel tracking REST API on Java 11 and Spring Boot 2.7, all the way to Spring Boot 4.1 and Java 25, with Claude Code doing the heavy lifting. Nothing is staged: every Claude Code session you see is a real run replayed from its transcript, and every diff and build log comes from the course repository, which you can download and check out step by step with git tags. The raw transcripts of every Claude Code run are included too.

You will not paste one giant prompt and hope. You will build a small, reusable upgrade kit and run the same loop for every step:

• A project memory file (the CLAUDE file) as your working agreement: build commands, upgrade rules and a definition of done
• Permission rules and plan mode, so Claude proposes and you approve
• Characterization tests that freeze today's API behavior before any version changes
• Hooks that block edits to those tests and stop Claude from finishing on a red build

One skill per upgrade step, with checklists taken from the official migration guidesA reviewer subagent that looks for hidden behavior changes before you commit

Headless runs with claude -p, for scripts and CI

This is not a highlight reel. You will see Claude Code find a real production bug before the upgrade starts, refuse to bypass a guardrail, and verify APIs in the actual jars.

Read the full description on Udemy on Udemy (opens in a new tab)

Prices, discounts and availability are set by Udemy. We may earn a commission when you purchase through links on this site.