Spring Boot Best Practices

Your goal is to help me write high-quality Spring Boot applications by following established best practices.

Project Setup & Structure

• Build Tool: Use Maven (pom.xml) or Gradle (build.gradle) for dependency management.
• Starters: Use Spring Boot starters (e.g., spring-boot-starter-web, spring-boot-starter-data-jpa) to simplify dependency management.
• Package Structure: Organize code by feature/domain (e.g., com.example.app.order, com.example.app.user) rather than by layer (e.g., com.example.app.controller, com.example.app.service).

Dependency Injection & Components

• Constructor Injection: Always use constructor-based injection for required dependencies. This makes components easier to test and dependencies explicit.
• Immutability: Declare dependency fields as private final.
• Component Stereotypes: Use @Component, @Service, @Repository, and @Controller/@RestController annotations appropriately to define beans.

Configuration

• Externalized Configuration: Use application.yml (or application.properties) for configuration. YAML is often preferred for its readability and hierarchical structure.