301 Frameworks Spring Boot Core Agent Skill

Spring Boot Core Guidelines

Apply Spring Boot Core guidelines for annotations, bean management, configuration, and dependency injection.

What is covered in this Skill?

• @SpringBootApplication and main application class
• Component annotations: @RestController, @Service, @Repository
• Bean definition, scoping, lifecycle
• Configuration classes and @ConfigurationProperties (with @Validated for fail-fast startup)
• Component scanning and package organization
• Conditional configuration and profiles (@Profile, @ConditionalOn*)
• Constructor dependency injection
• @Primary and @Qualifier for disambiguation when multiple beans share a type
• Bean minimization and composition
• Graceful shutdown for in-flight work
• Virtual threads on supported stacks for concurrency-bound workloads
• Jakarta EE namespace consistency (jakarta.* preferred; avoid mixing legacy javax.annotation / javax.validation)
• Scheduled tasks and background processing

Scope: Apply recommendations based on the reference rules and good/bad code examples.

Constraints

Before applying any Spring Boot changes, ensure the project compiles. If compilation fails, stop immediately. After applying improvements, run full verification.

• MANDATORY: Run ./mvnw compile or mvn compile before applying any change
• SAFETY: If compilation fails, stop immediately — compilation failure is a blocking condition
• VERIFY: Run ./mvnw clean verify or mvn clean verify after applying improvements
• BEFORE APPLYING: Read the reference for detailed rules, good/bad patterns, and constraints
• EDGE CASE: If request scope is ambiguous, stop and ask a clarifying question before applying changes
• EDGE CASE: If required inputs, files, or tooling are missing, report what is missing and ask whether to proceed with setup guidance

When to use this skill

• Review Java code for Spring Boot application
• Apply best practices for Spring Boot application in Java code
• Improve Spring Boot configuration properties and beans
• Review Spring Boot component scanning and profiles
• Tune Spring Boot graceful shutdown or virtual threads

Workflow

• Read reference and assess project context

Read references/301-frameworks-spring-boot-core.md and inspect the current project setup before proposing changes.

• Gather scope and decide target improvements

Identify requested outcomes, constraints, and the minimum safe set of changes to apply.

• Apply framework-aligned changes

Implement or refactor configuration/code following the reference patterns and project conventions.

• Run verification and report results

Execute appropriate build/tests and summarize what changed, what was verified, and any follow-up actions.

Reference

For detailed guidance, examples, and constraints, see references/301-frameworks-spring-boot-core.md.