# Plan: Scaffold Spring Boot Project + UserService

## Context
New empty project directory. User wants a full Spring Boot project scaffolded, then a `UserService` added following the same pattern as `ProductService`. The prompt referenced Spring Boot 4, which is not yet released — Spring Boot **3.4.x** (latest stable, supports Java 21 and virtual threads) will be used instead.

## Project Layout

```
/home/directlx/claude-src/cluade-user/
├── pom.xml
├── CLAUDE.md
└── src/
    ├── main/
    │   ├── java/com/example/app/
    │   │   ├── AppApplication.java
    │   │   ├── exception/
    │   │   │   └── ResourceNotFoundException.java
    │   │   ├── model/
    │   │   │   ├── User.java
    │   │   │   └── Product.java
    │   │   ├── repository/
    │   │   │   ├── UserRepository.java
    │   │   │   └── ProductRepository.java
    │   │   └── service/
    │   │       ├── ProductService.java   ← reference pattern
    │   │       └── UserService.java      ← main deliverable
    │   └── resources/
    │       └── application.properties
    └── test/
        └── java/com/example/app/
            └── service/
                └── UserServiceTest.java
```

## Key Decisions

- **Build**: Maven with `spring-boot-starter-parent` 3.4.2
- **Java**: 21 (records for entities, sealed classes available)
- **DB**: H2 in-memory (dev-ready; swap for PostgreSQL via `application.properties`)
- **Dependencies**: `spring-boot-starter-web`, `spring-boot-starter-data-jpa`, `h2`, `spring-boot-starter-test`
- **Package**: `com.example.app` (conventional; user can rename)

## Files to Create

### `pom.xml`
Spring Boot 3.4.2 parent, Java 21, web + JPA + H2 + test starters.

### `AppApplication.java`
Standard `@SpringBootApplication` entry point.

### `exception/ResourceNotFoundException.java`
`@ResponseStatus(HttpStatus.NOT_FOUND)` extending `RuntimeException` — used by both services for proper error handling.

### `model/Product.java` + `model/User.java`
JPA `@Entity` classes with `@Id @GeneratedValue`. User has: `id`, `name`, `email`, `createdAt`. Product has: `id`, `name`, `price`.

### `repository/ProductRepository.java` + `repository/UserRepository.java`
Extend `JpaRepository<T, Long>`. UserRepository adds `findByEmail(String email)`.

### `service/ProductService.java` (reference pattern)
Constructor-injected `ProductRepository`, `@Service`, methods: `findById`, `findAll`, `create`, `update`, `delete` — throws `ResourceNotFoundException` on missing entity.

### `service/UserService.java` (main deliverable)
Identical pattern to ProductService:
- `@Service` + constructor injection of `UserRepository`
- `findById(Long id)` — throws `ResourceNotFoundException`
- `findAll()` — returns `List<User>`
- `create(User user)` — saves and returns
- `update(Long id, User updated)` — finds, patches fields, saves
- `delete(Long id)` — finds (validates existence), then deletes

### `application.properties`
H2 console enabled, JPA `ddl-auto=create-drop`, show-sql for development.

### `UserServiceTest.java`
Mockito-based unit test (`@ExtendWith(MockitoExtension.class)`) covering findById (found + not-found), findAll, create, update, delete.

### `CLAUDE.md`
Project-specific guidance for future Claude sessions.

## Verification

```bash
# Build
mvn clean compile

# Run tests
mvn test

# Run single test class
mvn test -Dtest=UserServiceTest

# Start the app
mvn spring-boot:run
```