Java Coding Standards

// PASS: クラス/レコード: PascalCasepublic class MarketService {}public record Money(BigDecimal amount, Currency currency) {}
// PASS: メソッド/フィールド: camelCaseprivate final MarketRepository marketRepository;public Market findBySlug(String slug) {}
// PASS: 定数: UPPER_SNAKE_CASEprivate static final int MAX_PAGE_SIZE = 100;

// PASS: recordとfinalフィールドを優先public record MarketDto(Long id, String name, MarketStatus status) {}
public class Market {  private final Long id;  private final String name;  // getterのみ、setterなし}

// PASS: find*メソッドからOptionalを返すOptional<Market> market = marketRepository.findBySlug(slug);
// PASS: get()の代わりにmap/flatMapを使用return market    .map(MarketResponse::from)    .orElseThrow(() -> new EntityNotFoundException("Market not found"));

// PASS: 変換にストリームを使用し、パイプラインを短く保つList<String> names = markets.stream()    .map(Market::name)    .filter(Objects::nonNull)    .toList();
// FAIL: 複雑なネストされたストリームを避ける; 明確性のためにループを優先

throw new MarketNotFoundException(slug);

public <T extends Identifiable> Map<Long, T> indexById(Collection<T> items) { ... }

private static final Logger log = LoggerFactory.getLogger(MarketService.class);log.info("fetch_market slug={}", slug);log.error("failed_fetch_market slug={}", slug, ex);