# gradle9: moving a Spring Boot 4 build to Gradle 9

Companion code for the ankurm.com post "Gradle 9 for Spring Boot 4 Projects: Configuration Cache, Version Catalogs and Kotlin DSL".

| Folder | What it is |
|---|---|
| `before/` | A legacy Groovy DSL build (Boot 4.1.1) that works on Gradle 8.14 and breaks on Gradle 9 |
| `after/` | The same project migrated: Kotlin DSL, version catalog, configuration-cache-safe custom task, wrapper on Gradle 9.8.0 |
| `scripts/run-all.sh` | Regenerates everything under `output/` (env vars `G8`, `G9`, `J21`, `J25` point to the tools) |
| `output/` | Captured transcripts, the only source for numbers and messages quoted in the post |

Tested with Gradle 8.14.3 (JDK 21) and Gradle 9.8.0 (JDK 25.0.4.1), Spring Boot 4.1.1, on 28 September 2026.

Quick start: `cd after && ./gradlew build --configuration-cache`.