Adding a Micronaut example (#584)

Author: jabrena

.cursor/agents/robot-coordinator.md

@@ -1,10 +1,10 @@
 ---
 name: robot-coordinator
 model: inherit
-description: Tech lead orchestrator for Java Enterprise Development. Identifies framework from requirements, delegates to java-developer, spring-boot-developer, quarkus-coder, or micronaut-coder via plan task tables and the Parallel column; never implements code itself.
+description: Coordinator for Java Enterprise Development. Identifies framework from requirements, delegates to java-developer, spring-boot-developer, quarkus-coder, or micronaut-coder via plan task tables and the Parallel column; never implements code itself.
 ---
 
-You are a **Tech Lead Orchestrator** for Java Enterprise Development. Your primary responsibility is to coordinate technical work by **delegating** to specialized agents and **synthesizing** their outputs.
+You are a **Coordinator** for Java Enterprise Development. Your primary responsibility is to coordinate technical work by **delegating** to specialized agents and **synthesizing** their outputs.
 
 ### Core role (non-negotiable)
 

examples/requirements-examples/problem5/implementation3/.gitignore

@@ -0,0 +1,16 @@
+Thumbs.db
+.DS_Store
+.gradle
+build/
+target/
+out/
+.micronaut/
+.idea
+*.iml
+*.ipr
+*.iws
+.project
+.settings
+.classpath
+.factorypath
+tomcat/

examples/requirements-examples/problem5/implementation3/.mvn/wrapper/maven-wrapper.jar

@@ -0,0 +1,18 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.13/apache-maven-3.9.13-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.1/maven-wrapper-3.1.1.jar

examples/requirements-examples/problem5/implementation3/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,101 @@
+# Greek Gods API (US-001) — Micronaut
+
+Micronaut 4.x service: **`GET /api/v1/gods/greek`** returns a JSON array of Greek god names from PostgreSQL (read path never calls the upstream JSON server). Background sync upserts names from a configurable upstream base URL + **`GET /greek`**.
+
+## Run
+
+Prerequisites: JDK 21+, Maven (wrapper included), local PostgreSQL (or override URL via env).
+
+```bash
+./mvnw mn:run
+```
+
+Default datasource in `src/main/resources/application.yml` targets `jdbc:postgresql://localhost:5432/greek_gods` with user/password `postgres` / `postgres`. Override using Micronaut environment variables, for example:
+
+- `DATASOURCES_DEFAULT_URL`
+- `DATASOURCES_DEFAULT_USERNAME`
+- `DATASOURCES_DEFAULT_PASSWORD`
+
+Upstream sync (no hard-coded production URL in code):
+
+- `GREEK_GODS_UPSTREAM_BASE_URL` — overrides `greek-gods.upstream.base-url` (JDK `HttpClient` calls `{base-url}/greek`).
+
+## Build and tests
+
+```bash
+./mvnw clean verify
+```
+
+- **Unit tests** (`*Test`): Surefire — no Docker.
+- **Integration tests** (`*IT`): Failsafe — Testcontainers PostgreSQL, WireMock for sync; require Docker.
+
+Skip integration tests (faster local iteration):
+
+```bash
+./mvnw clean verify -DskipITs=true
+```
+
+or use the Maven profile:
+
+```bash
+./mvnw clean verify -Pfast
+```
+
+Run a subset of scenarios by JUnit tag (Failsafe / Surefire):
+
+```bash
+./mvnw -q verify -Dgroups=smoke
+./mvnw -q verify -Dgroups=error-handling
+```
+
+## JUnit tags (Gherkin mapping)
+
+| Tag | Meaning |
+|-----|---------|
+| `smoke`, `happy-path` | 20 canonical names, ordered, set equality |
+| `performance` | Single GET under 1 second |
+| `load-testing` | 100 concurrent GETs, wall clock under 2 seconds |
+| `error-handling` | 500 `application/problem+json` (normative fields); empty DB → `[]` |
+| `data-quality` | After WireMock stubbed sync, API matches stub payload |
+| `api-specification` | `Content-Type` includes `application/json`; JSON array of strings |
+
+**`@availability`** from the feature file is **not** automated (SLO/monitoring only).
+
+### CI flake note (`load-testing`)
+
+The **`load-testing`** scenario enforces **100 concurrent** requests within **2 seconds** total wall time. Shared CI agents can occasionally miss this window; if the build fails only on this test, re-run the job or use a larger runner. Tuning: increase the threshold only if product owners agree to relax the Gherkin timing.
+
+### Error-handling IT
+
+`GreekGodsDatabaseFailureIT` uses **`@MockBean` on `GreekGodRepository`** to simulate a read-path persistence failure while Flyway still runs against a real Testcontainers database. The HTTP response still satisfies ADR-001 (500 + `type`, `title`, `status`).
+
+## OpenAPI
+
+Runtime annotations align with `requirements3/design/greekController-oas.yaml`. After `./mvnw compile`, the generated spec is at `target/classes/META-INF/swagger/greek-gods-api-1.0.0.yml`.
+
+## Scheduling
+
+`@Scheduled` is provided by **`micronaut-context`** (transitive). There is no separate `micronaut-scheduling` artifact on the 4.10 BOM. Sync timing is configured with:
+
+- `greek-gods.sync.fixed-delay` (default `5m`)
+- `greek-gods.sync.initial-delay` (default `30s`)
+- `greek-gods.sync.scheduler-enabled` (`false` disables the job bean)
+- `greek-gods.sync.enabled` (skips work inside the job when `false`)
+
+## HTTP client note
+
+Upstream sync uses **`java.net.http.HttpClient`** (blocking `send`) with **`greek-gods.upstream.connect-timeout`** and **`read-timeout`** — no Micronaut **`micronaut-http-client`** / Netty on the outbound path.
+
+### Why `micronaut-core-reactive` stays on the classpath
+
+There is **no supported way** to run this app with **Micronaut’s HTTP server** (embedded Tomcat here) and **omit** `micronaut-core-reactive`:
+
+- Server-agnostic response encoding lives in **`io.micronaut.http.server.ResponseLifecycle`** (Micronaut 4.8+), used by both Netty and servlet runtimes.
+- That class imports **`io.micronaut.core.async.publisher.Publishers`** and **`LazySendingSubscriber`**, which are packaged **only** in **`micronaut-core-reactive`**, not in `micronaut-core`.
+- **`micronaut-http-server`**’s POM does not list `micronaut-core-reactive`, so many apps only got it **transitively** (e.g. via `micronaut-http-client`). This module declares it **explicitly** so the app still starts after removing the declarative client.
+
+So: **your controllers and upstream sync stay imperative/blocking**, but the framework still loads small reactive helper types for **response encoding**. Avoiding that JAR entirely would mean **not using Micronaut’s HTTP stack** (different framework or a non-HTTP entrypoint). Upstream improvement would be for `micronaut-http-server` to declare this dependency so every app gets a correct classpath by default ([micronaut-core](https://github.com/micronaut-projects/micronaut-core) `ResponseLifecycle`).
+
+---
+
+Micronaut reference: [User Guide](https://docs.micronaut.io/4.10.10/guide/index.html)

examples/requirements-examples/problem5/implementation3/README.md

@@ -0,0 +1,37 @@
+# AOT configuration properties for jar packaging
+# Please review carefully the optimizations enabled below
+# Check https://micronaut-projects.github.io/micronaut-aot/latest/guide/ for more details
+
+# Caches environment property values: environment properties will be deemed immutable after application startup.
+cached.environment.enabled=true
+
+# Precomputes Micronaut configuration property keys from the current environment variables
+precompute.environment.properties.enabled=true
+
+# Replaces logback.xml with a pure Java configuration
+logback.xml.to.java.enabled=true
+
+# Converts configuration files from YAML and properties to Java configuration
+property-source-loader.generate.enabled=true
+
+# Scans for service types ahead-of-time, avoiding classpath scanning at startup
+serviceloading.jit.enabled=true
+
+# Scans reactive types at build time instead of runtime
+scan.reactive.types.enabled=true
+
+# Deduces the environment at build time instead of runtime
+deduce.environment.enabled=true
+
+# Checks for the existence of some types at build time instead of runtime
+known.missing.types.enabled=true
+
+# Precomputes property sources at build time
+sealed.property.source.enabled=true
+
+# The list of service types to be scanned (comma separated)
+service.types=io.micronaut.context.env.PropertySourceLoader,io.micronaut.inject.BeanConfiguration,io.micronaut.inject.BeanDefinitionReference,io.micronaut.http.HttpRequestFactory,io.micronaut.http.HttpResponseFactory,io.micronaut.core.beans.BeanIntrospectionReference,io.micronaut.core.convert.TypeConverterRegistrar,io.micronaut.context.env.PropertyExpressionResolver
+
+# A list of types that the AOT analyzer needs to check for existence (comma separated)
+known.missing.types.list=io.reactivex.Observable,reactor.core.publisher.Flux,kotlinx.coroutines.flow.Flow,io.reactivex.rxjava3.core.Flowable,io.reactivex.rxjava3.core.Observable,io.reactivex.Single,reactor.core.publisher.Mono,io.reactivex.Maybe,io.reactivex.rxjava3.core.Single,io.reactivex.rxjava3.core.Maybe,io.reactivex.Completable,io.reactivex.rxjava3.core.Completable,io.methvin.watchservice.MacOSXListeningWatchService,io.micronaut.core.async.publisher.CompletableFuturePublisher,io.micronaut.core.async.publisher.Publishers.JustPublisher,io.micronaut.core.async.subscriber.Completable
+

examples/requirements-examples/problem5/implementation3/aot-jar.properties

@@ -0,0 +1,6 @@
+applicationType: default
+defaultPackage: info.jab.ms.gods
+testFramework: junit
+sourceLanguage: java
+buildTool: maven
+features: [app-name, http-client-test, java, java-application, junit, logback, maven, maven-enforcer-plugin, micronaut-aot, micronaut-http-validation, micronaut-processing-compiler-args, netty-server, properties, readme, serialization-jackson, shade, static-resources]