resilience: prove spring-boot-starter-aop was renamed to spring-boot-starter-aspectj, not removed

Maven Central's maven-metadata.xml for both artifact IDs, read together, shows aop's last release is 4.0.0-M2 and aspectj's first release is 4.0.0-M3 -- a rename at a milestone boundary, not a drop. The renamed starter's own published POM depends on exactly spring-aop + aspectjweaver, the two jars this pom.xml's dependency comment already claimed were needed; this commit adds the reproducible build-break proof, the metadata/POM evidence, and a new doc chapter, and backs the corrected companion-repo links from the resilience4j- circuit-breaker-spring-boot post.
2026-09-18 08:34:06 +00:00
parent baff043748
commit 604291067e
9 changed files with 179 additions and 2 deletions
@@ -48,6 +48,7 @@ All of these are diagnostics for the article. Delete [`DemoController`](src/main
 5. [Retry and transactions](docs/05-retry-and-transactions.md)
 6. [What is left for Resilience4j](docs/06-what-is-left-for-resilience4j.md)
 7. [Migrating from spring-retry](docs/07-migrating-from-spring-retry.md)
 8. [`spring-boot-starter-aop` was renamed, not removed](docs/08-starter-aop-renamed-to-starter-aspectj.md) - also backs the sibling post [Resilience4j Circuit Breaker in Spring Boot 4.1](https://ankurm.com/resilience4j-circuit-breaker-spring-boot/)
 ## Findings worth the trip
@@ -0,0 +1,24 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- NOT part of the main build (no parent module lists this directory). Exists only so
     scripts/reproduce-starter-aop-break.sh can run `mvn compile` against it and capture
     the real error. See docs/01-two-resilience-stacks.md. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>4.1.1</version>
    <relativePath/>
  </parent>
  <groupId>com.ankurm</groupId>
  <artifactId>break-demo</artifactId>
  <version>1.0.0</version>
  <dependencies>
    <!-- This is the dependency every pre-Boot-4 Resilience4j guide tells you to add.
         It no longer exists past 4.0.0-M2. -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
  </dependencies>
 </project>
@@ -1,6 +1,6 @@
 # 7. Migrating from spring-retry
-[← 6. What is left for Resilience4j](06-what-is-left-for-resilience4j.md) · [Index](../README.md)
+[← 6. What is left for Resilience4j](06-what-is-left-for-resilience4j.md) · [Index](../README.md) · [8. Starter rename: aop → aspectj →](08-starter-aop-renamed-to-starter-aspectj.md)
 The spring-retry README now says the project "is no longer maintained as an open-source project"
 and "has been superseded by Spring Framework 7". Its last release on Maven Central is 2.0.13.
@@ -0,0 +1,59 @@
 ← [What is left for Resilience4j](06-what-is-left-for-resilience4j.md) | [Migrating from spring-retry](07-migrating-from-spring-retry.md) →
 # `spring-boot-starter-aop` was renamed, not removed
 Every pre-Boot-4 AOP or Resilience4j guide tells you to add `spring-boot-starter-aop` when an
 annotation (`@Retryable`, `@ConcurrencyLimit`, Resilience4j's `@CircuitBreaker`, plain `@Aspect`
 beans, anything proxy-based) needs AspectJ on the classpath. On Boot 4.1, adding that dependency
 breaks the build before the application ever starts:
 ```
 [ERROR] 'dependencies.dependency.version' for org.springframework.boot:spring-boot-starter-aop:jar is missing.
 ```
 Captured by [`scripts/reproduce-starter-aop-break.sh`](../scripts/reproduce-starter-aop-break.sh)
 against the minimal [`broken-example/pom.xml`](../broken-example/pom.xml), which adds only that
 one dependency: [`00a-starter-aop-build-error.txt`](output/00a-starter-aop-build-error.txt).
 ## It was renamed, not dropped
 It is tempting to read that error as "the starter is gone, assemble `spring-aop` and
 `aspectjweaver` by hand instead" -- an earlier version of the sibling post this repo also serves
 said exactly that. It is half right and half wrong. Maven Central's `maven-metadata.xml` for both
 artifact IDs, read together, settles it:
 [`00b-starter-aspectj-metadata-timeline.txt`](output/00b-starter-aspectj-metadata-timeline.txt).
 `spring-boot-starter-aop`'s last-ever published version is `4.0.0-M2`. `spring-boot-starter-aspectj`'s
 first-ever published version is `4.0.0-M3` -- the very next milestone in the same 4.0 line, and it
 carries straight through to the 4.0.0 GA and every 4.1.x release since. That is a rename at a
 specific milestone boundary, not an unrelated new artifact and not a starter dropped with nothing
 replacing it.
 The renamed starter's own published POM confirms it bundles exactly the two jars this module's
 `pom.xml` needs:
 [`00c-starter-aspectj-pom-dependencies.txt`](output/00c-starter-aspectj-pom-dependencies.txt).
 ```xml
 <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-aspectj</artifactId>
 </dependency>
 ```
 is all this module adds (see [`pom.xml`](../pom.xml)) -- one line, version-managed by the parent
 POM like any other starter, resolving to `spring-aop` + `aspectjweaver` underneath. Assembling
 those two dependencies by hand still works and behaves identically, since it's what the starter
 does anyway, but there's no longer a reason to: the starter has the same name shape as every
 other Boot starter, it's just spelled `aspectj` instead of `aop` from the 4.0 line onward.
 <blockquote>If you're on a build that still references <code>spring-boot-starter-aop</code> after
 upgrading to Boot 4, the fix is a rename in your <code>pom.xml</code>, not a rewrite: swap the
 <code>artifactId</code> to <code>spring-boot-starter-aspectj</code> and nothing else changes.</blockquote>
 ## Going deeper
 - [`pom.xml`](../pom.xml) -- this module's own dependency, with the corrected comment
 - Maven Central: [`spring-boot-starter-aop/maven-metadata.xml`](https://repo1.maven.org/maven2/org/springframework/boot/spring-boot-starter-aop/maven-metadata.xml) and [`spring-boot-starter-aspectj/maven-metadata.xml`](https://repo1.maven.org/maven2/org/springframework/boot/spring-boot-starter-aspectj/maven-metadata.xml) -- rel="nofollow"
 - [Resilience4j Circuit Breaker in Spring Boot 4.1: What It's Still For](https://ankurm.com/resilience4j-circuit-breaker-spring-boot/) -- the sibling post this same correction applies to
 ← [What is left for Resilience4j](06-what-is-left-for-resilience4j.md) | [Migrating from spring-retry](07-migrating-from-spring-retry.md) →
@@ -0,0 +1,13 @@
 [ERROR] [ERROR] Some problems were encountered while processing the POMs:
 [ERROR] 'dependencies.dependency.version' for org.springframework.boot:spring-boot-starter-aop:jar is missing. @ line 19, column 17
 @ 
 [ERROR] The build could not read 1 project -> [Help 1]
 [ERROR]   
 [ERROR]   The project com.ankurm:break-demo:1.0.0 (/home/claude/work/repos/spring-boot-demo-migration/resilience/broken-example/pom.xml) has 1 error
 [ERROR]     'dependencies.dependency.version' for org.springframework.boot:spring-boot-starter-aop:jar is missing. @ line 19, column 17
 [ERROR] 
 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
 [ERROR] 
 [ERROR] For more information about the errors and possible solutions, please read the following articles:
 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/ProjectBuildingException
@@ -0,0 +1,33 @@
 Captured 2026-09-18 from repo1.maven.org (Maven Central), not an aggregator or blog.
 --- org/springframework/boot/spring-boot-starter-aop/maven-metadata.xml ---
 <latest>4.0.0-M2</latest>
 <release>4.0.0-M2</release>
 ... version list ends at:
  <version>3.5.16</version>
  <version>4.0.0-M1</version>
  <version>4.0.0-M2</version>
 </versions>
 <lastUpdated>20260625105758</lastUpdated>
 --- org/springframework/boot/spring-boot-starter-aspectj/maven-metadata.xml ---
 <latest>4.2.0-M1</latest>
 <release>4.2.0-M1</release>
 ... version list starts at:
  <version>4.0.0-M3</version>
  <version>4.0.0-RC1</version>
  <version>4.0.0-RC2</version>
  <version>4.0.0</version>
  <version>4.0.1</version>
  ...
  <version>4.1.0</version>
  <version>4.1.1</version>
  <version>4.2.0-M1</version>
 </versions>
 <lastUpdated>20260820133928</lastUpdated>
 Reading the two lists together: spring-boot-starter-aop's last-ever release is 4.0.0-M2.
 spring-boot-starter-aspectj's first-ever release is 4.0.0-M3 -- the very next milestone in the
 4.0 line. It then carries through 4.0.0-RC1, RC2, the 4.0.0 GA, every 4.0.x and 4.1.x patch, and
 into the 4.2.0-M1 pre-release. That is a rename at a specific milestone boundary, not two
 unrelated artifacts and not a starter that was dropped with nothing replacing it.
@@ -0,0 +1,35 @@
 Captured 2026-09-18 from repo1.maven.org (Maven Central):
 https://repo1.maven.org/maven2/org/springframework/boot/spring-boot-starter-aspectj/4.1.1/spring-boot-starter-aspectj-4.1.1.pom
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-aspectj</artifactId>
 <version>4.1.1</version>
 <name>spring-boot-starter-aspectj</name>
 <description>Starter for using aspect-oriented programming with AspectJ</description>
 <dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
    <version>4.1.1</version>
    <scope>compile</scope>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>7.0.9</version>
    <scope>compile</scope>
  </dependency>
  <dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.25.1</version>
    <scope>compile</scope>
  </dependency>
 </dependencies>
 The renamed starter's own POM declares exactly spring-aop + aspectjweaver as compile
 dependencies -- the same two jars this module's own pom.xml already lists as the reason it
 depends on spring-boot-starter-aspectj. There is no missing third piece and no behavioural
 difference from assembling the two jars by hand; the starter just does it for you, correctly
 versioned, in one line.
@@ -48,7 +48,10 @@
    </dependency>
    <!-- Resilience4j: annotations are woven by its own aspects, so AspectJ must be present.
-         Boot 4 renamed spring-boot-starter-aop to spring-boot-starter-aspectj. -->
+         Boot 4 renamed spring-boot-starter-aop to spring-boot-starter-aspectj (confirmed against
         Maven Central's maven-metadata.xml for both artifact IDs and the renamed starter's own
         published POM, which depends on exactly spring-aop + aspectjweaver, the two jars this
         file used to add by hand before that was verified). See docs/08-starter-aop-renamed-to-starter-aspectj.md. -->
    <dependency>
      <groupId>io.github.resilience4j</groupId>
      <artifactId>resilience4j-spring-boot4</artifactId>
@@ -0,0 +1,9 @@
 #!/usr/bin/env bash
 # Reproduces, and captures, the real build error from adding spring-boot-starter-aop on
 # Spring Boot 4.1 -- the dependency every pre-Boot-4 Resilience4j / AOP guide tells you to add.
 # See docs/08-starter-aop-renamed-to-starter-aspectj.md.
 set -uo pipefail
 cd "$(dirname "$0")/../broken-example"
 mvn -B -q compile 2>&1 | grep -v '^Picked up\|^WARNING' > ../docs/output/00a-starter-aop-build-error.txt
 echo "captured to docs/output/00a-starter-aop-build-error.txt:"
 cat ../docs/output/00a-starter-aop-build-error.txt