Skip to content
cccskills
FreePublished on GitHub

spring-boot-migration

Use when preparing a Spring Boot 3 application for Boot 4, upgrading to Boot 3.5 first, removing deprecated APIs, auditing dependencies, or planning a staged Framework 7 migration.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills
See how to install

Files included (4)

  • SKILL.md2.6 KB
  • agents/openai.yaml205 B
  • examples/bad-migration-plan.md238 B
  • examples/good-migration-plan.md356 B

SKILL.md (original)

Review the instructions the agent will receive before you install.

Spring Boot 3 to 4 Migration

Migrate in controlled stages. Keep behavior changes separate from the framework upgrade.

Establish the baseline

  1. Upgrade to the latest Boot 3.5 maintenance release.
  2. Run unit, slice, integration, startup, and migration tests before changing the major version.
  3. Remove Boot 3 deprecations and record all explicitly versioned dependencies.
  4. Compare the Boot 3.5 and Boot 4 dependency-management reports.
  5. Verify Spring Cloud and other portfolio release-train compatibility independently.

Prepare for Boot 4

  • Require Java 17 or newer; prefer Java 21 for application builds.
  • Replace javax.* remnants with Jakarta APIs before the upgrade.
  • Remove Undertow assumptions; Boot 4 requires a Servlet 6.1-compatible container.
  • Inventory Jackson 2 custom modules, serializers, ObjectMapper beans, and package imports.
  • Inventory test annotations, especially @MockBean, @SpyBean, and implicit MockMvc setup.
  • Add spring-boot-properties-migrator temporarily after changing the Boot version, then remove it.

Migrate dependencies deliberately

Boot 4 is more modular. Prefer dedicated starters over relying on incidental transitive dependencies. Expect dedicated starters for web MVC, security tests, Flyway/Liquibase, and technology-specific tests. Use the classic starters only as a temporary diagnostic bridge, never as the final dependency model.

Verify the result

  • Run the application with every supported profile.
  • Exercise schema migration against a production-like database copy.
  • Verify JSON contracts, security failures, pagination, and error responses.
  • Confirm actuator exposure, logging, metrics, and tracing behavior.
  • Remove the properties migrator and all classic starters before declaring the migration complete.

Examples

  • See examples/good-migration-plan.md for a staged migration.
  • See examples/bad-migration-plan.md for a risky one-step upgrade.

Gotchas

  • Agent jumps from an old Boot 3 minor directly to Boot 4 - upgrade to current 3.5 first.
  • Agent changes framework versions and business behavior together - isolate the migration diff.
  • Agent assumes all Boot 3 starters keep the same names and transitive dependencies - audit each one.
  • Agent leaves spring-boot-properties-migrator in production - remove it after configuration cleanup.
  • Agent treats passing compilation as completion - verify runtime wiring, JSON, security, and tests.

Reviews

No reviews yet. Tell others what you thought.

Comments

No login needed. Share how it worked for you, ask a question, or note where it did not run.

No comments yet. Be the first to write one.

Comments are published right away. Do not include personal information such as email addresses or phone numbers. Up to 2 URLs.

0 / 1,000 characters

This form is protected by reCAPTCHA, and the Google Privacy Policy and Terms of Service apply.

More skills from this repository

ai-observability

Free

Use when adding Spring AI-specific model observations, token usage, latency, externally configured cost attribution, advisor telemetry, or protected prompt and completion logging. Use production-observability for general service metrics, health, logs, and OTLP setup.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

api-versioning

Free

Use when versioning Spring MVC or WebFlux APIs in Spring Boot 4 / Spring Framework 7. Covers built-in mapping versions, request version resolution, defaults, supported versions, and deprecation headers.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

api-versioning

Free

Use when versioning Spring MVC or WebFlux APIs in Spring Boot 3 / Spring Framework 6. Covers explicit URL, header, and media-type strategies, compatibility rules, and deprecation handling.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

configuration-properties

Free

Use when introducing or correcting grouped Spring Boot configuration, typed property binding, validation, profiles or secret injection. Do not rewrite unrelated single-value configuration.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

container-native-deployment

Free

Use when packaging a Spring Boot 3 application as an OCI image or GraalVM native executable. Covers buildpacks, layered images, JVM containers, AOT hints, probes, security, and verification.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

container-native-deployment

Free

Use when packaging Spring Boot 4 as an OCI image, JVM container, AOT application, or GraalVM native executable. Covers buildpacks, layers, runtime hints, probes, security, and verification.

The English summary is being prepared. Showing the original description.

rrezartprebreza/spring-boot-skills313Updated Oct 17, 2026

See all skills by rrezartprebreza

Report a problem with this skill