domain-modeling

Partial of docs/use-cases/UC-001-create-customer/. Owner: domain-modeling. Inherits the canonical names from 00-caso-de-uso.md — doesn't reinvent them. Contains no code. Form references in .claude/skills/domain-modeling/templates/*.java.example.

Package base: dev.nerviz.bankapp. Paths below are relative to src/main/java/dev/nerviz/bankapp/.

Aggregate root: Customer. Boundary: the customer alone — no reference to another aggregate.

Value objects

SecurityNumber exposes value() (the 11 digits, for persistence mapping) and masked() (********* followed by the last 2 digits). Its toString() returns masked(), so a SecurityNumber concatenated into a log line or an exception message never prints the full value.

All record, immutable, validation in the compact constructor. Shape: templates/ValueObject.java.example.

Exception family: NEW — five classes in the domain.exception package: DomainException (abstract, errorCode required), NotFoundException, ValidationException, BusinessRuleViolationException, ConflictException. Shapes in templates/DomainException.java.example and the four typed ones. NotFoundException is unused by this case and still created: the family is created once, whole.

Order inside register: 7, then 8, then 9 — a future date reports itself as such, not as underage. plusYears on 29 February yields 28 February in a non-leap year (mother spec).

Input — clean architecture: no interface. The concrete use case is the input boundary.

application/usecase/customer/CreateCustomerUseCase.java

class CreateCustomerUseCase
    CreateCustomerUseCase(CustomerRepository customerRepository, Clock clock)
    CustomerId create(CreateCustomerCommand command)

create:

1. builds SecurityNumber.of(command.securityNumber()) (invariants 4-5);
2. customerRepository.existsBySecurityNumber(securityNumber) → true raises
3. Customer.register(new id, command.name(), securityNumber, command.birthDate(), clock)
4. customerRepository.save(customer) and returns its id().

The transaction opens and closes on this method (@.claude/rules/architecture-ddd.md § Application) — the annotation lives on this application-layer class. Constructor injection, private final fields. Throws ValidationException, BusinessRuleViolationException and SecurityNumberAlreadyRegisteredException.

Validating the format (step 1) before the uniqueness lookup keeps a malformed number from reaching the database query.

Command — application/usecase/customer/CreateCustomerCommand.java

none — the mother spec fixes no publication: no other system needs to learn that a customer was created. No CustomerCreated is designed; a future case that needs it adds it in its own ## Impact on approved use cases.

Refines the 00-caso-de-uso.md rows marked Detailed by: domain-modeling.

Requirement for the wiring, not a domain class: a java.time.Clock bean (Clock.systemUTC()) in infrastructure/config/ClockConfig.java — NEW, none exists. Written by the executor with the configuration; recorded here because the use case's constructor needs it.

none — no force in the spec, no symptom on disk. The static factories register / rehydrate are the naming rule's creation convention (@.claude/rules/naming.md § Methods), not a catalog pattern; nothing in the mother spec enumerates variants or rules per type, and src/main/java holds no domain or application class yet.

none — UC-001 is the first case.