configuration-properties/ @ConfigurationProperties vs @Value on Spring Boot 4.1.1.
The relaxed-binding matrix is generated by binding each spelling rather than
transcribed, and re-checked against real processes -- the in-process probe was
wrong twice before it was right. Records the three findings that came out of it:
@Value does get relaxed resolution inside Spring Boot (Boot attaches
ConfigurationPropertySources), the configuration processor silently stops
generating metadata on JDK 23+ when declared as a plain dependency, and @Valid is
not what makes nested constraints run.
profiles-and-config/ Precedence, profiles, spring.config.import and config trees.
/precedence reports every source holding a property in rank order with file and
line, which turns "my profile file had no effect" into a two-line answer. Also
pins the counterintuitive one: an imported file outranks the file that imported it.
spring-aop/ Designators, proxy types, and aspects that do not fire.
One advice per supported designator so the reference table is generated from real
matches; all fourteen unsupported designators fed to the parser. Two corrections to
the reference documentation: unsupported designators throw
UnsupportedPointcutPrimitiveException (extends RuntimeException, not
IllegalArgumentException), and spring-boot-starter-aop was renamed to
spring-boot-starter-aspectj in Boot 4.
19 contract tests across the three modules, 15 captured transcripts, all regenerated
by scripts/run-all.sh. Verified on Spring Boot 4.1.1, Spring Framework 7.0.9,
JDK 25.0.4.1.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gip4srpzMwjgoba6uEfbr5
Adds spring-boot-startup-time/, the companion project for BLOG-618: a runnable
Spring Boot 4.1.1 application on JDK 25 that installs BufferingApplicationStartup
and FlightRecorderApplicationStartup behind a system property, and a /diag/startup
endpoint that computes step self time -- the number /actuator/startup does not give
you and the one that names the actual culprits.
Captured under docs/output/: the step tree sorted both ways, the same startup as JFR
events, a +5000-class experiment putting 0.11 ms per scanned class on the classpath
scan tax, the silent truncation a 2048-step buffer performs, and JDK 25 AOT cache
timings (6.93 s to 4.82 s). Post body and metadata live in post/.
Moves the existing Actuator project into actuator-in-production/ so the repository
holds one directory per article; the root README is now an index.
Companion repository for the ankurm.com article. Every transcript in docs/output/
was produced by running this project; scripts/run-all.sh regenerates all of them.
Verified against Spring Boot 4.1.1 / Framework 7.0.9 / Security 7.1.1 /
Micrometer 1.17.1 / kafka-clients 4.2.1 on Temurin JDK 25.0.4.1+1.
