# Backend Data Java

> Implementar adapters JPA (persistência) Java. Usar quando o pedido envolver repositório concreto, JpaEntity ou mapeamento DB↔domínio.

- Skill: `eskcti/backend-data-java` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add eskcti/backend-data-java`
- Raw SKILL.md: https://api.skillmd.com/api/skills/eskcti/backend-data-java/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: EskCti (https://skillmd.com/u/eskcti)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/eskcti/backend-data-java

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# Backend Data (Java / JPA)

## Overview

Adapters em `modules/<bc>/infrastructure/persistence/CustomerRepositoryAdapter.java` — implementa `domain.repository.CustomerRepository`.

## Guidelines

- JPA entity: `CustomerJpaEntity` — separada de `domain.entity.Customer`.
- Spring Data: `CustomerJpaRepository extends JpaRepository<CustomerJpaEntity, UUID>`.
- Mapeamento explícito `toDomain()` / `toJpaEntity()`.
- Converter exceções JPA → `DomainError` / `Result.err`.
- `@Repository` no adapter; **sem** JPA no pacote `packages/<bc>/`.

## Workflow

1. Migration via `config-jpa-java`.
2. Implementar `*JpaEntity`, `*JpaRepository`, `*RepositoryAdapter`.
3. Testes integração — `test-e2e-java`.

## Global Standards

- Consultar `../config-shared-core-java/references/java-namespace-layout.md`.