Three new article modules: configuration binding, profiles and config data, Spring AOP

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

profiles-and-config/docs/output/02-profile-file-loses.txt

@@ -0,0 +1,41 @@
+== does application-prod.yaml win? ==
+
+demo.datasource-url is set in application.yaml and again in application-prod.yaml.
+
+--- 1. prod profile active, no environment variable ---
+$ java -jar target/profiles-and-config-1.0.0.jar --spring.profiles.active=prod
+  active profiles : prod, prod-db, prod-metrics
+  effective value : jdbc:postgresql://prod-db:5432/orders
+    1. jdbc:postgresql://prod-db:5432/orders <- 'file application-prod.yaml' via location 'optional:classpath:/''}
+    2. jdbc:h2:mem:default                <- 'file application.yaml' via location 'optional:classpath:/''}
+  holders that lost: 1
+
+--- 2. identical, plus one leftover environment variable ---
+$ DEMO_DATASOURCE_URL=jdbc:postgresql://leftover:5432/orders \
+    java -jar target/profiles-and-config-1.0.0.jar --spring.profiles.active=prod
+  active profiles : prod, prod-db, prod-metrics
+  effective value : jdbc:postgresql://leftover:5432/orders
+    1. jdbc:postgresql://leftover:5432/orders <- OriginAwareSystemEnvironmentPropertySource {name='systemEnvironment'}
+    2. jdbc:postgresql://prod-db:5432/orders <- 'file application-prod.yaml' via location 'optional:classpath:/''}
+    3. jdbc:h2:mem:default                <- 'file application.yaml' via location 'optional:classpath:/''}
+  holders that lost: 2
+
+The profile-specific file is still loaded and still holds its value -- it is listed,
+and it lost. Config data is item 3 in the documented precedence list; OS environment
+variables are item 5, and later items win.
+
+== the full property-source stack, in order ==
+$ curl -s localhost:8080/sources
+   1. MapPropertySource                  server.ports
+   2. ConfigurationPropertySourcesPropertySource configurationProperties
+   3. SimpleCommandLinePropertySource    commandLineArgs
+   4. StubPropertySource                 servletConfigInitParams
+   5. ServletContextPropertySource       servletContextInitParams
+   6. PropertiesPropertySource           systemProperties
+   7. OriginAwareSystemEnvironmentPropertySource systemEnvironment
+   8. RandomValuePropertySource          random
+   9. OriginTrackedMapPropertySource     Config resource 'class path resource [application-prod-metrics.yaml]' via location 'optional:classpath:/'
+  10. OriginTrackedMapPropertySource     Config resource 'class path resource [application-prod-db.yaml]' via location 'optional:classpath:/'
+  11. OriginTrackedMapPropertySource     Config resource 'class path resource [application-prod.yaml]' via location 'optional:classpath:/'
+  12. OriginTrackedMapPropertySource     Config resource 'class path resource [application.yaml]' via location 'optional:classpath:/'
+  13. ApplicationInfoPropertySource      applicationInfo