Java Scaffold

/java-scaffold — New Spring Boot Project Generator

You are a Spring Boot project bootstrapper. Use this skill to create a new project from scratch.

Already have a project? Use /java-crud instead — it adds a CRUD feature to an existing codebase.

Step 1 — Gather requirements (all at once)

Ask these questions in a single message:

1. Project name — e.g., shop-api, user-service
2. Java version — 8, 11, 17, or 21 (recommend 21 for new projects)
3. Spring Boot version — 2.7.x, 3.2.x, 3.3.x, or 4.0.x (recommend 3.3.x; 4.0.x requires Java 17+)
4. Build tool — Maven or Gradle
5. Base package — e.g., com.example.shop
6. First domain entity — e.g., Product, User, Order
7. Database — PostgreSQL, MySQL, or H2 (H2 only for throwaway prototypes)

Confirm before generating:

Scaffolding: shop-api
Java 21 | Spring Boot 3.3.x | Maven
Package: com.example.shop
First entity: Product
Database: PostgreSQL (Testcontainers for tests)
Generate? (yes to proceed)

Step 2 — Generate build file

Use the Maven or Gradle template from references/templates.md. Fill in {spring-boot-version}, {project-name}, and {java-version}.

For Spring Boot 4.0.x: uses jakarta.persistence.* (same as 3.x). Requires Java 17 minimum.

Step 3 — Generate package structure

Use the directory layout from references/templates.md.

Step 4 — Generate application.yml

Use the application.yml and application-dev.yml templates from references/templates.md.

Note: Never commit real credentials. Use environment variables or Spring Vault for production secrets.

Step 5 — Generate starter feature

Generate the first entity using the same templates as /java-crud:

• Entity class (with @PrePersist / @PreUpdate timestamps)
• Repository extending JpaRepository
• Service with @Transactional(readOnly = true) reads
• Controller with ResponseEntity returns
• Request/Response DTOs (records for Java 16+, classes for Java 8–15)
• GlobalExceptionHandler with @RestControllerAdvice — see references/templates.md
• Unit test (Mockito)
• Repository integration test (Testcontainers)

Spring Boot version rules:

• 3.x+: use jakarta.persistence.*, @SQLRestriction for soft delete
• 2.x: use javax.persistence.*, @Where(clause = "deleted = false") for soft delete

Step 6 — Post-generation checklist

• Run mvn spring-boot:run or ./gradlew bootRun to verify it starts
• Start a local PostgreSQL: docker run -p 5432:5432 -e POSTGRES_PASSWORD=postgres postgres:16-alpine
• Add Flyway or Liquibase for schema management before going to production
• Add Spring Boot Actuator for health checks: spring-boot-starter-actuator

Next Steps

• Add more features → /java-crud <EntityName>
• Review the generated code → /java-review
• Generate more tests → /java-test
• Security review → /java-security-check or java-security-reviewer agent