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Generates Spring Boot 3.x configurations, creates REST controllers, implements Spring Security 6 authentication flows, sets up Spring Data JPA repositories, and configures reactive WebFlux endpoints.
The skill file stays in the publisher's repository.
Paste the copied command in a terminal. It installs this SKILL.md into that agent.
npx skills add Jeffallan/claude-skills --skill spring-boot-engineer -a cursor -y
Generates Spring Boot 3.x configurations, creates REST controllers, implements Spring Security 6 authentication flows, sets up Spring Data JPA repositories, and configures reactive WebFlux endpoints. Use when building Spring Boot 3.x applications, microservices, or reactive Java applications; invoke for Spring Data JPA, Spring Security 6, WebFlux, Spring Cloud integration, Java REST API design, or Microservices Java architecture.
Generates Spring Boot 3.x configurations, creates REST controllers, implements Spring Security 6 authentication flows, sets up Spring Data JPA repositories, and configures reactive WebFlux endpoints. Use when building Spring Boot 3.x applications, microservices, or reactive Java applications; invoke for Spring Data JPA, Spring Security 6, WebFlux, Spring Cloud integration, Java REST API design, or Microservices Java architecture.
./mvnw test (or ./gradlew test) and confirm all pass before proceeding. If tests fail: review the stack trace, isolate the failing assertion or component, fix the issue, and re-run the full suite/actuator/health returns UP. If health is DOWN: check the components detail in the response, resolve the failing component (e.g., datasource, broker), and re-validateLoad detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Web Layer | references/web.md | Controllers, REST APIs, validation, exception handling |
| Data Access | references/data.md | Spring Data JPA, repositories, transactions, projections |
| Security | references/security.md | Spring Security 6, OAuth2, JWT, method security |
| Cloud Native | references/cloud.md | Spring Cloud, Config, Discovery, Gateway, resilience |
| Testing | references/testing.md | @SpringBootTest, MockMvc, Testcontainers, test slices |
A standard Spring Boot feature consists of these layers. Use these as copy-paste starting points.
@Entity
@Table(name = "products")
public class Product {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@NotBlank
private String name;
@DecimalMin("0.0")
private BigDecimal price;
// getters / setters or use @Data (Lombok)
}
public interface ProductRepository extends JpaRepository<Product, Long> {
List<Product> findByNameContainingIgnoreCase(String name);
}
@Service
public class ProductService {
private final ProductRepository repo;
public ProductService(ProductRepository repo) { // constructor injection — no @Autowired
this.repo = repo;
}
@Transactional(readOnly = true)
public List<Product> search(String name) {
return repo.findByNameContainingIgnoreCase(name);
}
@Transactional
public Product create(ProductRequest request) {
var product = new Product();
product.setName(request.name());
product.setPrice(request.price());
return repo.save(product);
}
}
@RestController
@RequestMapping("/api/v1/products")
@Validated
public class ProductController {
private final ProductService service;
public ProductController(ProductService service) {
this.service = service;
}
@GetMapping
public List<Product> search(@RequestParam(defaultValue = "") String name) {
return service.search(name);
}
@PostMapping
@ResponseStatus(HttpStatus.CREATED)
public Product create(@Valid @RequestBody ProductRequest request) {
return service.create(request);
}
}
public record ProductRequest(
@NotBlank String name,
@DecimalMin("0.0") BigDecimal price
) {}
@RestControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(MethodArgumentNotValidException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public Map<String, String> handleValidation(MethodArgumentNotValidException ex) {
return ex.getBindingResult().getFieldErrors().stream()
.collect(Collectors.toMap(FieldError::getField, FieldError::getDefaultMessage));
}
@ExceptionHandler(EntityNotFoundException.class)
@ResponseStatus(HttpStatus.NOT_FOUND)
public Map<String, String> handleNotFound(EntityNotFoundException ex) {
return Map.of("error", ex.getMessage());
}
}
@WebMvcTest(ProductController.class)
class ProductControllerTest {
@Autowired MockMvc mockMvc;
@MockBean ProductService service;
@Test
void createProduct_validRequest_returns201() throws Exception {
var product = new Product(); product.setName("Widget"); product.setPrice(BigDecimal.TEN);
when(service.create(any())).thenReturn(product);
mockMvc.perform(post("/api/v1/products")
.contentType(MediaType.APPLICATION_JSON)
.content("""{"name":"Widget","price":10.0}"""))
.andExpect(status().isCreated())
.andExpect(jsonPath("$.name").value("Widget"));
}
}
| Rule | Correct Pattern |
|---|---|
| Constructor injection | public MyService(Dep dep) { this.dep = dep; } |
| Validate API input | @Valid @RequestBody MyRequest req on every mutating endpoint |
| Type-safe config | @ConfigurationProperties(prefix = "app") bound to a record/class |
| Appropriate stereotype | @Service for business logic, @Repository for data, @RestController for HTTP |
| Transaction scope | @Transactional on multi-step writes; @Transactional(readOnly = true) on reads |
| Hide internals | Catch domain exceptions in @RestControllerAdvice; return problem details, not stack traces |
| Externalize secrets | Use environment variables or Spring Cloud Config — never application.properties |
@Autowired on fields)@Component when @Service/@Repository/@Controller applies.block() inside a WebFlux chain)application.properties/application.ymlWebSecurityConfigurerAdapter)Maintained by @jeffallan, Principal Consultant at Synergetic Solutions