spring-boot

name	spring-boot
description	Spring Boot patterns — auto-configuration, dependency injection, REST controllers, JPA, and actuator.
layer	domain
category	backend
triggers	["spring boot","spring framework","spring jpa","spring security","spring actuator"]
inputs	["API endpoint requirements or domain model specifications","Performance or configuration issues with Spring Boot apps","JPA entity relationship design questions","Security configuration needs"]
outputs	["Spring Boot REST controllers with proper patterns","JPA entity mappings and repository queries","Security configuration with Spring Security","Production-ready application.yml configuration"]
linksTo	["postgresql","redis","docker","kubernetes"]
linkedFrom	[]
riskLevel	low
memoryReadPolicy	selective
memoryWritePolicy	none
sideEffects	[]

Spring Boot Patterns & Best Practices

Purpose

Provide expert guidance on Spring Boot application architecture, auto-configuration, REST API development, JPA/Hibernate patterns, and production-grade configuration. Covers Spring Boot 3.x with Jakarta EE, virtual threads, and GraalVM native image support.

Key Patterns

Project Structure

Follow the standard layered architecture:

src/main/java/com/example/app/
├── config/            # @Configuration classes
├── controller/        # @RestController endpoints
├── service/           # @Service business logic
├── repository/        # Spring Data JPA repositories
├── entity/            # JPA @Entity classes
├── dto/               # Request/response DTOs
├── exception/         # Custom exceptions + @ControllerAdvice
├── mapper/            # Entity ↔ DTO mappers (MapStruct)
└── Application.java   # @SpringBootApplication entry point

REST Controllers

Proper controller structure with validation and response entities:

@RestController
@RequestMapping("/api/v1/users")
@RequiredArgsConstructor
public class UserController {

    private final UserService userService;

    @GetMapping
    public ResponseEntity<Page<UserResponse>> list(
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "20") int size) {
        Pageable pageable = PageRequest.of(page, size, Sort.by("createdAt").descending());
        return ResponseEntity.ok(userService.findAll(pageable));
    }

    @GetMapping("/{id}")
    public ResponseEntity<UserResponse> getById(@PathVariable UUID id) {
        return ResponseEntity.ok(userService.findById(id));
    }

    @PostMapping
     ResponseEntity<UserResponse>  {
           userService.create(request);
           ServletUriComponentsBuilder.fromCurrentRequest()
                .path()
                .buildAndExpand(created.id())
                .toUri();
         ResponseEntity.created(location).body(created);
    }

    
     ResponseEntity<UserResponse>  {
         ResponseEntity.ok(userService.update(id, request));
    }

    
    
       {
        userService.delete(id);
    }
}