Scaffold a Spring Boot application with start.spring.io, then apply a small set of opinionated defaults. Out of scope for now: front-ends (Vue/React/Angular), cloud deployment (Azure), Git setup, CRaC and AOT images.
pom.xml or build.gradle(.kts), this is an existing project: do not regenerate it. Read its Spring Boot, Java and test-framework versions and follow them. Never upgrade versions implicitly; propose an upgrade and wait for the user's decision.java -version (JDK matching the chosen Java version), docker --version (needed for Testcontainers and Compose). On the default path (current Boot via start.spring.io) Maven/Gradle need not be installed: the generated wrapper is used. The Boot 3.5 fallback needs Maven or Gradle installed once to create the wrapper (see versions.md).data-jpa, postgresql, security, docker-compose, testcontainers when a database or auth is needed).Follow references/versions.md: query https://start.spring.io/metadata/client at run time for the latest stable Spring Boot release, fall back to the documented pinned values if offline. Do not hardcode latest anywhere.
Use the start.spring.io HTTP API with explicit, pinned parameters (no piped installers). Replace the values in capitals.
Maven:
curl -fsS https://start.spring.io/starter.zip \
-d type=maven-project -d language=java -d packaging=jar \
-d bootVersion=BOOT_VERSION -d javaVersion=JAVA_VERSION \
-d groupId=com.example -d artifactId=demo -d name=demo \
-d packageName=com.example.demo -d baseDir=demo \
-d dependencies=web,actuator,validation,devtools \
-o demo.zip && unzip -q demo.zip && rm demo.zipGradle: same command with -d type=gradle-project (Groovy DSL) or -d type=gradle-project-kotlin (Kotlin DSL; the language stays java).
Inspect the result (ls demo, read the build file) and make sure the wrapper (mvnw or gradlew) is executable. Add -d dependencies=...,data-jpa,postgresql,docker-compose,testcontainers for a database project.
| Area | What to do | Reference |
|---|---|---|
| Boot 3 vs 4 differences | Starter names, Jackson 3, test modules | references/spring-boot-4.md |
| Configuration | application.properties or .yml (match the project), profiles, @ConfigurationProperties, secrets via environment | references/configuration.md |
| Database | PostgreSQL, Hibernate settings, Compose for dev, Testcontainers for tests | references/database.md |
| Logging | SLF4J, parameterized messages, levels, structured logging | references/logging.md |
| Security | Spring Security basics, secure defaults, Problem Details | references/security.md |
| Docker | JVM image and GraalVM native image Dockerfiles | references/docker.md |
| Testing | See the spring-boot-testing skill (slices, Testcontainers, Failsafe) | skills/spring-boot-testing |
| Best practices | See the java-springboot skill and instructions/springboot.instructions.md | skills/java-springboot |
Keep dotfiles minimal: a .gitignore covering target/, build/, .gradle/, IDE folders and .env; never commit .env (commit a .env.sample).
./mvnw verify (Maven) or ./gradlew build (Gradle)../mvnw spring-boot:run or ./gradlew bootRun, then curl -fsS localhost:8080/actuator/health must return {"status":"UP"}.Adapted from the Apache-2.0 skill jdubois/dr-jskill; see references/PROVENANCE.md.