divenhuang88/everything-claude-code/java-coding-standards

// PASS: Classes/Records: PascalCase
public class MarketService {}
public record Money(BigDecimal amount, Currency currency) {}
 
// PASS: Methods/fields: camelCase
private final MarketRepository marketRepository;
public Market findBySlug(String slug) {}
 
// PASS: Constants: UPPER_SNAKE_CASE
private static final int MAX_PAGE_SIZE = 100;

// PASS: Favor records and final fields
public record MarketDto(Long id, String name, MarketStatus status) {}
 
public class Market {
  private final Long id;
  private final String name;
  // getters only, no setters
}

// PASS: Return Optional from find* methods
Optional<Market> market = marketRepository.findBySlug(slug);
 
// PASS: Map/flatMap instead of get()
return market
    .map(MarketResponse::from)
    .orElseThrow(() -> new EntityNotFoundException("Market not found"));

// PASS: Use streams for transformations, keep pipelines short
List<String> names = markets.stream()
    .map(Market::name)
    .filter(Objects::nonNull)
    .toList();
 
// FAIL: Avoid complex nested streams; prefer loops for clarity

throw new MarketNotFoundException(slug);

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

src/main/java/com/example/app/
  config/
  controller/
  service/
  repository/
  domain/
  dto/
  util/
src/main/resources/
  application.yml
src/test/java/... (mirrors main)

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