feat(spring-caffeine): initialize Spring Caffeine example project wit…

.github/labeler.yml

@@ -26,6 +26,10 @@
   - changed-files:
       - any-glob-to-any-file: 'spring-batch-file-examples/**/*'
 
+"project: spring-caffeine-example":
+  - changed-files:
+      - any-glob-to-any-file: 'spring-caffeine-example/**/*'
+
 "project: springwolf-example":
   - changed-files:
       - any-glob-to-any-file: 'spring-wolf-example/**/*'

.github/workflows/spring-caffeine-example.yml

@@ -0,0 +1,68 @@
+name: spring-caffeine-example CI Build
+
+on:
+  pull_request:
+    branches: [master]
+    paths:
+      - "spring-caffeine-example/**"
+    types:
+      - opened
+      - synchronize
+      - reopened
+
+jobs:
+
+  integration-tests:
+    name: Run Unit & Integration Tests
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: spring-caffeine-example
+    strategy:
+      matrix:
+        distribution: [ 'temurin' ]
+        java: [ '21' ]
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v5.1.0
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: ${{ matrix.distribution }}
+          cache: 'maven'
+      - name: Build and analyze
+        run: ./mvnw clean verify
+
+  health-check:
+    name: Health Check on Services
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository and submodules
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+
+      - name: Extract service names from docker compose
+        id: services
+        run: |
+          echo "services<<EOF" >> $GITHUB_OUTPUT
+          docker compose -f ./spring-caffeine-example/compose.yaml config --services >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+
+      - name: Start containers with Compose Action
+        uses: hoverkraft-tech/compose-action@v2.4.2
+        with:
+          compose-file: './spring-caffeine-example/compose.yaml'
+          services: ${{ steps.services.outputs.services }}
+          up-flags: '--build'
+          down-flags: '--volumes'
+
+      - name: Wait for containers to initialize
+        run: sleep 10
+
+      - name: Check container health
+        run: |
+          ./.github/scripts/check-container-health.sh "${{ steps.services.outputs.services }}"

README.md

@@ -27,6 +27,7 @@ Below you will find a summary table of each subproject. For more details, please
 | [Spring Boot + Mysql](./spring-mysql-example)                             | Demonstrates a basic integration between Spring Boot and Mysql.                   |
 | [Spring Boot + Grafana + Prometheus](./spring-prometheus-grafana-example) | Demonstrates a basic integration between Spring Boot With Grafana and Prometheus. |
 | [Spring Boot + Spring Wolf](./spring-wolf-example)                        | Demonstrates a basic integration between Spring Boot and Spring Wolf.             |
+| [Spring Boot + Caffeine](./spring-caffeine-example)                       | Demonstrates a basic integration between Spring Boot and Caffeine.                |
 ---
 
 ## Tech Stack

pom.xml

@@ -23,6 +23,7 @@
         <module>spring-batch-file-examples</module>
         <module>spring-batch-db-examples</module>
         <module>spring-wolf-example</module>
+        <module>spring-caffeine-example</module>
     </modules>
 
 </project>

spring-caffeine-example/.dockerignore

@@ -0,0 +1,62 @@
+# Include any files or directories that you don't want to be copied to your
+# container here (e.g., local build artifacts, temporary files, etc.).
+#
+# For more help, visit the .dockerignore file reference guide at
+# https://docs.docker.com/go/build-context-dockerignore/
+
+**/.DS_Store
+**/.classpath
+**/.dockerignore
+**/.env
+**/.factorypath
+**/.git
+**/.gitignore
+**/.idea
+**/.project
+**/.sts4-cache
+**/.settings
+**/.toolstarget
+**/.vs
+**/.vscode
+**/.next
+**/.cache
+**/*.dbmdl
+**/*.jfm
+**/charts
+**/docker-compose*
+**/compose.y*ml
+**/Dockerfile*
+**/secrets.dev.yaml
+**/values.dev.yaml
+**/vendor
+LICENSE
+README.md
+**/*.class
+**/*.iml
+**/*.ipr
+**/*.iws
+**/*.log
+**/.apt_generated
+**/.gradle
+**/.gradletasknamecache
+**/.nb-gradle
+**/.springBeans
+**/build
+**/dist
+**/gradle-app.setting
+**/nbbuild
+**/nbdist
+**/nbproject/private
+**/target
+*.ctxt
+.mtj.tmp
+.mvn/timing.properties
+buildNumber.properties
+dependency-reduced-pom.xml
+hs_err_pid*
+pom.xml.next
+pom.xml.releaseBackup
+pom.xml.tag
+pom.xml.versionsBackup
+release.properties
+replay_pid*

spring-caffeine-example/.gitattributes

@@ -0,0 +1,2 @@
+/mvnw text eol=lf
+*.cmd text eol=crlf

spring-caffeine-example/.github/workflows/maven.yml

@@ -0,0 +1,30 @@
+name: CI Build
+
+on:
+  push:
+    branches:
+      - "**"
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        distribution: [ 'temurin' ]
+        java: [ '21' ]
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup Java 21
+        uses: actions/setup-java@v5
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: ${{ matrix.distribution }}
+          cache: 'maven'
+
+      - name: Grant execute permission for mvnw
+        run: chmod +x mvnw
+
+      - name: Build with Maven
+        run: ./mvnw clean verify

spring-caffeine-example/.gitignore

@@ -0,0 +1,32 @@
+target/
+.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

spring-caffeine-example/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,3 @@
+wrapperVersion=3.3.4
+distributionType=only-script
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.11/apache-maven-3.9.11-bin.zip

spring-caffeine-example/Dockerfile

@@ -0,0 +1,49 @@
+FROM eclipse-temurin:21-jdk-jammy as deps
+
+WORKDIR /build
+
+COPY --chmod=0755 mvnw mvnw
+COPY .mvn/ .mvn/
+
+RUN --mount=type=bind,source=pom.xml,target=pom.xml \
+    --mount=type=cache,target=/root/.m2 ./mvnw dependency:go-offline -DskipTests
+
+FROM deps as package
+
+WORKDIR /build
+
+COPY ./src src/
+RUN --mount=type=bind,source=pom.xml,target=pom.xml \
+    --mount=type=cache,target=/root/.m2 \
+    ./mvnw package -DskipTests && \
+    mv target/$(./mvnw help:evaluate -Dexpression=project.artifactId -q -DforceStdout)-$(./mvnw help:evaluate -Dexpression=project.version -q -DforceStdout).jar target/app.jar
+
+FROM package as extract
+
+WORKDIR /build
+
+RUN java -Djarmode=layertools -jar target/app.jar extract --destination target/extracted
+
+
+FROM eclipse-temurin:21-jre-jammy AS final
+
+
+ARG UID=10001
+RUN adduser \
+    --disabled-password \
+    --gecos "" \
+    --home "/nonexistent" \
+    --shell "/sbin/nologin" \
+    --no-create-home \
+    --uid "${UID}" \
+    appuser
+USER appuser
+
+COPY --from=extract build/target/extracted/dependencies/ ./
+COPY --from=extract build/target/extracted/spring-boot-loader/ ./
+COPY --from=extract build/target/extracted/snapshot-dependencies/ ./
+COPY --from=extract build/target/extracted/application/ ./
+
+EXPOSE 7079
+
+ENTRYPOINT [ "java", "org.springframework.boot.loader.launch.JarLauncher" ]

spring-caffeine-example/README.md

@@ -0,0 +1,29 @@
+# spring-caffeine-example
+
+## Overview
+
+This project is a simple and practical example demonstrating how to use **Caffeine** as an in-memory cache in a Spring Boot application.
+
+The main goal is to show how Caffeine can be used to cache:
+- external service calls (e.g. HTTP/Feign clients)
+- database lookups
+
+The project focuses on using **Caffeine directly**, avoiding unnecessary abstractions, to achieve better performance, predictability, and simplicity.
+
+---
+
+## Main Endpoint
+
+| Environment | Curl                                                        |
+|-------------|-------------------------------------------------------------|
+| Local       | curl --location 'http://localhost:8080/caffeine/v1/request' |
+| Docker      | curl --location 'http://localhost:7079/caffeine/v1/request' |
+
+---
+
+## Related Resources
+
+| Description              | Link                                           |
+|--------------------------|------------------------------------------------|
+| Caffeine Github          | https://github.com/ben-manes/caffeine          |
+| Introduction to Caffeine | https://www.baeldung.com/java-caching-caffeine |

spring-caffeine-example/compose.yaml

@@ -0,0 +1,23 @@
+services:
+
+  app:
+    container_name: app
+    build:
+      context: .
+    environment:
+      SPRING_PROFILES_ACTIVE: prd
+      SERVER_PORT: 7079
+      H2_DB_URL: jdbc:h2:mem:caffeine-db;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
+      H2_DB_DRIVER: org.h2.Driver
+      H2_DB_USERNAME: sa
+      H2_DB_PASSWORD: ""
+      H2_CONSOLE_ENABLED: false
+      H2_CONSOLE_PATH: /h2-console
+      H2_INIT_MODE: always
+      H2_INIT_SCHEMA: classpath:sql/init.sql
+      CAFFEINE_VERSION_URL: localhost:7079/external
+      CAFFEINE_EXPIRES: 60 #seconds
+      CAFFEINE_CAPACITY: 200
+      CAFFEINE_MAXIMUM_SIZE: 500
+    ports:
+      - "7079:7079"