# Spring AOP: designators, proxies, and aspects that do not fire

Companion project for [**Spring AOP Explained**](https://ankurm.com/) on ankurm.com.

Two halves. One set of aspects that work — one advice per pointcut designator, so the reference
table is generated from real matches. One set that does not fire, each for a different reason,
each paired with its fix.

## Versions

| | |
|---|---|
| Spring Boot | 4.1.1 |
| Spring Framework | 7.0.9 |
| AspectJ weaver | 1.9.25.1 |
| JDK | Eclipse Temurin 25.0.4.1 (LTS) |

## Read this before copying a dependency block

In Spring Boot 3 the starter was `spring-boot-starter-aop`. In Spring Boot 4 it is
**`spring-boot-starter-aspectj`**. The old artifact's last publication is `4.0.0-M2` and its
last GA is `3.5.16`, so a pre-4 dependency block fails resolution with a missing-version error.

## Quickstart

```bash
export JAVA_HOME=/path/to/jdk-25
mvn -DskipTests package
./scripts/run-all.sh          # regenerate every transcript in docs/output/
mvn test                      # 6 contract tests
```

## Endpoints

| Endpoint | Purpose |
|---|---|
| `GET /aop/proxies` | per bean: proxied or not, which kind, and the advisor list |
| `GET /aop/designators` | exercises every advised method, reports what each designator matched |
| `GET /aop/parser` | feeds supported and unsupported expressions to the pointcut parser |
| `GET /aop/broken` | runs the failure gallery and reports that nothing fired |

## Documentation

1. [What Spring AOP actually is](docs/01-what-spring-aop-is.md)
2. [The designator reference](docs/02-designators.md)
3. [JDK dynamic proxies and CGLIB](docs/03-proxy-types.md)
4. [Advice types and ordering](docs/04-advice-types.md)
5. [Six aspects that do not fire](docs/05-broken-aspect-gallery.md)
6. [Diagnosing a silent aspect](docs/06-diagnosing-a-silent-aspect.md)

## Captured output

| File | Produced by |
|---|---|
| [`00-versions.txt`](docs/output/00-versions.txt) | `scripts/demo-versions.sh` |
| [`01-designators.txt`](docs/output/01-designators.txt) | `scripts/demo-designators.sh` |
| [`02-proxy-types.txt`](docs/output/02-proxy-types.txt) | `scripts/demo-proxy-types.sh` |
| [`03-broken-gallery.txt`](docs/output/03-broken-gallery.txt) | `scripts/demo-broken-gallery.sh` |

## Two corrections to the reference documentation

- Unsupported designators throw **`UnsupportedPointcutPrimitiveException`**, which extends
  `RuntimeException` directly — not `IllegalArgumentException` as the docs state. Catching the
  documented type will not catch it.
- The framework default is interface-based proxying, but **Spring Boot sets
  `proxy-target-class=true`**, so you get CGLIB even for beans that implement interfaces. That
  changes which designators match; `scripts/demo-proxy-types.sh` shows both.