Ankur Mhatre
86246dc860
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
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spring-boot-demo
Companion code for the Spring Boot articles on ankurm.com.
One directory per article. Each is a self-contained Maven project with its own README.md,
numbered documentation chapters under docs/, and captured real output under docs/output/
that a single script regenerates. Every figure quoted in an article came out of one of those
files.
| Directory | Article | What it demonstrates |
|---|---|---|
actuator-in-production/ |
Spring Boot Actuator in Production | endpoint exposure defaults, securing Actuator, custom health indicators and how they hang |
spring-boot-startup-time/ |
Why Your Spring Boot App Takes 8 Seconds to Start | BufferingApplicationStartup, JFR startup events, self time vs total time, the classpath-scan tax, the JDK 25 AOT cache |
configuration-properties/ |
@ConfigurationProperties vs @Value in Spring Boot 4 | relaxed binding measured three ways, record constructor binding, validation, IDE metadata generation |
profiles-and-config/ |
Spring Boot Profiles Done Right | the precedence stack made visible, config trees and ConfigMaps, why a profile file loses to an environment variable |
spring-aop/ |
Spring AOP Explained | every pointcut designator with real matches, JDK vs CGLIB proxies, six aspects that do not fire |
Articles whose text is kept here rather than only on the blog have it under
<directory>/post/ — post.md for the body and meta.md for the title, excerpt and
categories.
Running any of them
Each project needs a JDK 25 and Maven 3.9:
cd <directory>
export JAVA_HOME=/path/to/jdk-25
mvn -DskipTests package
./scripts/run-all.sh # regenerate every transcript under docs/output/
Licence
MIT — see LICENSE.