Create Spring Boot Java Project

Create a Spring Boot Java project

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.

Step 0: Detect before you create

• If the working directory already contains a 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.
• Check the tools: 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).
• Ask only for what is missing: project name, group id, package, build tool (default Maven), dependencies (default: web, actuator, validation, devtools; add data-jpa, postgresql, security, docker-compose, testcontainers when a database or auth is needed).

Step 1: Resolve versions

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.

Step 2: Generate the project

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.zip

Gradle: 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.

Step 3: Apply the defaults

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).

Step 4: Verify

1. Build and test: ./mvnw verify (Maven) or ./gradlew build (Gradle).
2. Run: ./mvnw spring-boot:run or ./gradlew bootRun, then curl -fsS localhost:8080/actuator/health must return {"status":"UP"}.
3. Report the chosen versions and anything that was skipped or deferred.

Provenance

Adapted from the Apache-2.0 skill jdubois/dr-jskill; see references/PROVENANCE.md.