Table of Contents
Claude Code – 스킬 생성 및 사용법
스킬이란?
Claude 에서 만들어 공개한 기법입니다.
다른 AI 에서도 사용가능하므로 Claude Skill 이 아니라 Agent Skill 로 명명합니다.
Agent Skills는 Claude의 기능을 확장하는 모듈입니다.
패턴이나 가이드라인을 정리해 놓고, 그것에 맞게 AI 가 코딩하게 하는 기법입니다.
샘플
---
name: my-skill-name
description: A clear description of what this skill does and when to use it
---
# My Skill Name
[Add your instructions here that Claude will follow when this skill is active]
## Examples
- Example usage 1
- Example usage 2
## Guidelines
- Guideline 1
- Guideline 2실제코드 (오픈소스)
문서가 깨지므로 따옴표를 물결무늬문자로 변경하였습니다.
---
name: springboot-patterns
description: Spring Boot architecture patterns, REST API design, layered services, data access, caching, async processing, and logging. Use for Java Spring Boot backend work.
---
# Spring Boot Development Patterns
Spring Boot architecture and API patterns for scalable, production-grade services.
## REST API Structure
~~~java
@RestController
@RequestMapping("/api/markets")
@Validated
class MarketController {
private final MarketService marketService;
MarketController(MarketService marketService) {
this.marketService = marketService;
}
@GetMapping
ResponseEntity<Page<MarketResponse>> list(
@RequestParam(defaultValue = "0") int page,
@RequestParam(defaultValue = "20") int size) {
Page<Market> markets = marketService.list(PageRequest.of(page, size));
return ResponseEntity.ok(markets.map(MarketResponse::from));
}
@PostMapping
ResponseEntity<MarketResponse> create(@Valid @RequestBody CreateMarketRequest request) {
Market market = marketService.create(request);
return ResponseEntity.status(HttpStatus.CREATED).body(MarketResponse.from(market));
}
}
~~~
## Repository Pattern (Spring Data JPA)
~~~java
public interface MarketRepository extends JpaRepository<MarketEntity, Long> {
@Query("select m from MarketEntity m where m.status = :status order by m.volume desc")
List<MarketEntity> findActive(@Param("status") MarketStatus status, Pageable pageable);
}
~~~
## Service Layer with Transactions
~~~java
@Service
public class MarketService {
private final MarketRepository repo;
public MarketService(MarketRepository repo) {
this.repo = repo;
}
@Transactional
public Market create(CreateMarketRequest request) {
MarketEntity entity = MarketEntity.from(request);
MarketEntity saved = repo.save(entity);
return Market.from(saved);
}
}
~~~
## DTOs and Validation
~~~java
public record CreateMarketRequest(
@NotBlank @Size(max = 200) String name,
@NotBlank @Size(max = 2000) String description,
@NotNull @FutureOrPresent Instant endDate,
@NotEmpty List<@NotBlank String> categories) {}
public record MarketResponse(Long id, String name, MarketStatus status) {
static MarketResponse from(Market market) {
return new MarketResponse(market.id(), market.name(), market.status());
}
}
~~~
## Exception Handling
~~~java
@ControllerAdvice
class GlobalExceptionHandler {
@ExceptionHandler(MethodArgumentNotValidException.class)
ResponseEntity<ApiError> handleValidation(MethodArgumentNotValidException ex) {
String message = ex.getBindingResult().getFieldErrors().stream()
.map(e -> e.getField() + ": " + e.getDefaultMessage())
.collect(Collectors.joining(", "));
return ResponseEntity.badRequest().body(ApiError.validation(message));
}
@ExceptionHandler(AccessDeniedException.class)
ResponseEntity<ApiError> handleAccessDenied() {
return ResponseEntity.status(HttpStatus.FORBIDDEN).body(ApiError.of("Forbidden"));
}
@ExceptionHandler(Exception.class)
ResponseEntity<ApiError> handleGeneric(Exception ex) {
// Log unexpected errors with stack traces
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
.body(ApiError.of("Internal server error"));
}
}
~~~
## Caching
Requires `@EnableCaching` on a configuration class.
~~~java
@Service
public class MarketCacheService {
private final MarketRepository repo;
public MarketCacheService(MarketRepository repo) {
this.repo = repo;
}
@Cacheable(value = "market", key = "#id")
public Market getById(Long id) {
return repo.findById(id)
.map(Market::from)
.orElseThrow(() -> new EntityNotFoundException("Market not found"));
}
@CacheEvict(value = "market", key = "#id")
public void evict(Long id) {}
}
~~~
## Async Processing
Requires `@EnableAsync` on a configuration class.
~~~java
@Service
public class NotificationService {
@Async
public CompletableFuture<Void> sendAsync(Notification notification) {
// send email/SMS
return CompletableFuture.completedFuture(null);
}
}
~~~
## Logging (SLF4J)
~~~java
@Service
public class ReportService {
private static final Logger log = LoggerFactory.getLogger(ReportService.class);
public Report generate(Long marketId) {
log.info("generate_report marketId={}", marketId);
try {
// logic
} catch (Exception ex) {
log.error("generate_report_failed marketId={}", marketId, ex);
throw ex;
}
return new Report();
}
}
~~~
## Middleware / Filters
~~~java
@Component
public class RequestLoggingFilter extends OncePerRequestFilter {
private static final Logger log = LoggerFactory.getLogger(RequestLoggingFilter.class);
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException {
long start = System.currentTimeMillis();
try {
filterChain.doFilter(request, response);
} finally {
long duration = System.currentTimeMillis() - start;
log.info("req method={} uri={} status={} durationMs={}",
request.getMethod(), request.getRequestURI(), response.getStatus(), duration);
}
}
}
~~~
## Pagination and Sorting
~~~java
PageRequest page = PageRequest.of(pageNumber, pageSize, Sort.by("createdAt").descending());
Page<Market> results = marketService.list(page);
~~~
## Error-Resilient External Calls
~~~java
public <T> T withRetry(Supplier<T> supplier, int maxRetries) {
int attempts = 0;
while (true) {
try {
return supplier.get();
} catch (Exception ex) {
attempts++;
if (attempts >= maxRetries) {
throw ex;
}
try {
Thread.sleep((long) Math.pow(2, attempts) * 100L);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
throw ex;
}
}
}
}
~~~
## Rate Limiting (Filter + Bucket4j)
**Security Note**: The `X-Forwarded-For` header is untrusted by default because clients can spoof it.
Only use forwarded headers when:
1. Your app is behind a trusted reverse proxy (nginx, AWS ALB, etc.)
2. You have registered `ForwardedHeaderFilter` as a bean
3. You have configured `server.forward-headers-strategy=NATIVE` or `FRAMEWORK` in application properties
4. Your proxy is configured to overwrite (not append to) the `X-Forwarded-For` header
When `ForwardedHeaderFilter` is properly configured, `request.getRemoteAddr()` will automatically
return the correct client IP from the forwarded headers. Without this configuration, use
`request.getRemoteAddr()` directly—it returns the immediate connection IP, which is the only
trustworthy value.
~~~java
@Component
public class RateLimitFilter extends OncePerRequestFilter {
private final Map<String, Bucket> buckets = new ConcurrentHashMap<>();
/*
* SECURITY: This filter uses request.getRemoteAddr() to identify clients for rate limiting.
*
* If your application is behind a reverse proxy (nginx, AWS ALB, etc.), you MUST configure
* Spring to handle forwarded headers properly for accurate client IP detection:
*
* 1. Set server.forward-headers-strategy=NATIVE (for cloud platforms) or FRAMEWORK in
* application.properties/yaml
* 2. If using FRAMEWORK strategy, register ForwardedHeaderFilter:
*
* @Bean
* ForwardedHeaderFilter forwardedHeaderFilter() {
* return new ForwardedHeaderFilter();
* }
*
* 3. Ensure your proxy overwrites (not appends) the X-Forwarded-For header to prevent spoofing
* 4. Configure server.tomcat.remoteip.trusted-proxies or equivalent for your container
*
* Without this configuration, request.getRemoteAddr() returns the proxy IP, not the client IP.
* Do NOT read X-Forwarded-For directly—it is trivially spoofable without trusted proxy handling.
*/
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException {
// Use getRemoteAddr() which returns the correct client IP when ForwardedHeaderFilter
// is configured, or the direct connection IP otherwise. Never trust X-Forwarded-For
// headers directly without proper proxy configuration.
String clientIp = request.getRemoteAddr();
Bucket bucket = buckets.computeIfAbsent(clientIp,
k -> Bucket.builder()
.addLimit(Bandwidth.classic(100, Refill.greedy(100, Duration.ofMinutes(1))))
.build());
if (bucket.tryConsume(1)) {
filterChain.doFilter(request, response);
} else {
response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
}
}
}
~~~
## Background Jobs
Use Spring’s `@Scheduled` or integrate with queues (e.g., Kafka, SQS, RabbitMQ). Keep handlers idempotent and observable.
## Observability
- Structured logging (JSON) via Logback encoder
- Metrics: Micrometer + Prometheus/OTel
- Tracing: Micrometer Tracing with OpenTelemetry or Brave backend
## Production Defaults
- Prefer constructor injection, avoid field injection
- Enable `spring.mvc.problemdetails.enabled=true` for RFC 7807 errors (Spring Boot 3+)
- Configure HikariCP pool sizes for workload, set timeouts
- Use `@Transactional(readOnly = true)` for queries
- Enforce null-safety via `@NonNull` and `Optional` where appropriate
**Remember**: Keep controllers thin, services focused, repositories simple, and errors handled centrally. Optimize for maintainability and testability.
설치방법
전역 Skills 위치: ~/.claude/skills/{skill-name}/SKILL.md
프로젝트 Skills 위치: .claude/skills/{skill-name}/SKILL.md
사용법
기본적으로는 클로드가 알아서 필요한 스킬을 찾아서 참조합니다.
하지만, 아래와 같이 특정 스킬을 사용하도록 강제할 수 있습니다.
/{skill-name} 프롬프트 입력