asmhatreandClaude Sonnet 5.5
85074ed51a
Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b4VQVEJWetTT1dYzyJ
2.2 KiB
2.2 KiB
boot4-migration
Companion module for the ankurm.com post Spring Boot 3 to 4 Migration Guide (Updated for 4.1 and 4.2).
One small service (Web MVC, Security, Actuator, JDBC + Flyway, AOP aspect, RestClient.Builder,
a Jackson serializer, three tests) in two forms:
| Directory | What it is | Built by |
|---|---|---|
before/ |
the service on Spring Boot 3.5.16 | never by a normal build; scripts/run-all.sh copies it to a scratch dir |
after/ |
the same service migrated to Spring Boot 4.1.2 | cd after && mvn verify |
run-all.sh builds before/ as written, then bumps only the parent version and records what
breaks at each step: the build error, the javac errors, the start-up failure report, the
things that start fine but behave differently, and the test failures. Every file in output/ is
a real transcript from that script (JDK 25.0.5, Maven 3.9).
export JAVA_HOME=/path/to/jdk-25
./scripts/run-all.sh # 15-25 minutes on a shared 2-vCPU box; needs Maven Central
| Output | Shows |
|---|---|
01-before-boot35.txt |
before/ builds and runs on 3.5.16 (the baseline every other file is compared with) |
02-bump-only-compile-errors.txt |
only the parent version changed: Maven POM error, then 12 javac errors |
03-compiles-but-will-not-start.txt |
imports ported, starters not: compiles, fails at start-up (no RestClient.Builder) |
04-starts-but-silently-wrong.txt |
starts, answers 200, but Flyway never ran, logs never rotate |
05-properties-migrator.txt |
what spring-boot-properties-migrator does and does not report |
06-after-boot41.txt |
after/: 8 tests pass, same endpoints, new health groups |
07-jackson-property-order.txt |
bean property order on Jackson 2, Jackson 3, and use-jackson2-defaults |
08-test-compile-errors.txt |
@MockBean and the old @AutoConfigureMockMvc package |
09-test-runtime-failure.txt |
a plain @Mock field is null: compiles, fails at run time |
10-security-dsl-compile-errors.txt |
the real javac message for the removed authorizeHttpRequests() chain |
Not covered: Gradle, Kotlin, native image, and any library that has not shipped a Boot 4 release.