# Campus Used Book Trading System

C/S architecture: JavaFX client → RESTful API → Spring Boot server → MySQL.

## Tech stack

| Layer | Technology | Version |
|-------|-----------|---------|
| Client | JavaFX + FXML + Scene Builder | 23.0.2 |
| Client HTTP | JDK `java.net.http.HttpClient` | built-in |
| JSON | Jackson (`jackson-databind` + `jackson-datatype-jsr310`) | 2.17.3 |
| Server | Spring Boot Web | 3.4.4 |
| ORM | MyBatis-Plus (`mybatis-plus-spring-boot3-starter`) | 3.5.9 |
| Database | MySQL 8.0+ (connector 8.4.0) | |
| Build | Maven (no wrapper, requires system `mvn`) | 3.9+ |
| Java | corretto-23 (`JAVA_HOME` must target JDK 23) | |
| Lombok | 1.18.36 (annotation processor configured in parent POM) | |

**Must compile with JDK 23.** The system JDK may be newer; always set `JAVA_HOME`:
```sh
JAVA_HOME=/path/to/corretto-23.0.2 mvn clean install
```

On this machine: `JAVA_HOME=/home/yangyi/.jdks/corretto-23.0.2`

## Modules

```
common/   space.anyi.common    — entities, DTOs (LoginRequest, RegisterRequest, R<T>, PageResult<T>), enums
server/   space.anyi.server    — Spring Boot app (controllers → services → MyBatis-Plus mappers)
client/   space.anyi.client    — JavaFX app (App.java entry, FXML views, controllers, HTTP service layer)
```

Dependency: `server → common`, `client → common`. Client and server communicate only via HTTP; no direct dependency.

## Build & run

```sh
# Full build (use JDK 23!)
JAVA_HOME=/path/to/corretto-23 mvn clean install

# Build single module (common must be installed first for server/client)
mvn install -pl common
mvn compile -pl server
mvn compile -pl client

# Run server
mvn spring-boot:run -pl server

# Run client
mvn javafx:run -pl client          # via plugin
# or directly run space.anyi.client.UIApplication main class
```

## Database

- MySQL 8.0+, database `campus_book_trade`, charset `utf8mb4`
- Schema: `sql/campus_book_trade.sql` (tables: `user`, `book`, `transaction_record`)
- Default credentials: `root`/`root` on `localhost:3306`
- Config: `server/src/main/resources/application.yml`
- Run SQL directly against local instance before starting server

## Architecture

### Server REST API

All under `/api`, unified response `R<T>` = `{code, message, data}`. Port 8080.

| Method | Path | Purpose |
|--------|------|---------|
| POST | `/api/user/login` | Login |
| POST | `/api/user/register` | Register |
| GET | `/api/user` | List all users (paginated: `?page=&size=`) |
| GET | `/api/user/{id}` | Get user |
| PUT | `/api/user/{id}` | Update user |
| DELETE | `/api/user/{id}` | Delete user |
| GET | `/api/book?keyword=&category=&page=&size=` | Search books (paginated) |
| GET | `/api/book/all` | List all books |
| GET | `/api/book/{id}` | Book detail |
| GET | `/api/book/my?sellerId=` | Seller's own books |
| POST | `/api/book` | Create listing |
| PUT | `/api/book/{id}` | Update book |
| DELETE | `/api/book/{id}` | Delete book |
| POST | `/api/transaction` | Purchase |
| GET | `/api/transaction` | List all transactions (paginated) |
| GET | `/api/transaction/{id}` | Transaction detail |
| GET | `/api/transaction/user/{userId}` | User's transactions |
| PUT | `/api/transaction/{id}` | Update transaction |
| DELETE | `/api/transaction/{id}` | Delete transaction |
| GET | `/api/statistics/summary` | Total transaction amount & count |
| GET | `/api/statistics/top-departments` | Top 3 departments by sales |
| GET | `/api/statistics/top-books` | Top 5 best-selling books |
| GET | `/api/statistics/discount-rates` | Avg discount rate by department |

### Client JavaFX views

```
login.fxml → LoginController
register.fxml → RegisterController
main.fxml → MainController (TabPane with 6 tabs: Browse, Transactions, Profile, Seller Dashboard, Statistics, Admin)
```

FXML location: `client/src/main/resources/fxml/*.fxml`

### Identity

Simplified auth: login stores `User` object in `LoginUserHolder` (in-memory). Client sends `userId` in request body/params. No JWT.

### Key packages

```
server/
  config/WebConfig.java          — CORS config
  controller/*Controller.java    — REST endpoints
  service/*Service.java          — business logic
  service/impl/*ServiceImpl.java
  mapper/*Mapper.java            — MyBatis-Plus BaseMapper

client/
  App.java                       — JavaFX entry, scene switching
  controller/*Controller.java    — JavaFX controllers
  service/*Service.java          — HTTP call wrappers
  util/HttpClientUtil.java       — singleton HttpClient + Jackson JSON
  util/LoginUserHolder.java      — current user session
  resources/fxml/*.fxml          — Scene Builder layouts
  resources/css/style.css
```

## Notes

- No test framework configured yet
- No CI, no formatter, no linter
- IntelliJ IDEA project (`.idea/` tracked, configured for JDK 23)
- Lombok `@Data` on entities/DTOs; annotation processor configured in parent POM's `maven-compiler-plugin`
- MyBatis-Plus entity annotations (`@TableName`, `@TableId`, `@TableField`) live in `common` entities alongside Lombok; the `mybatis-plus-spring-boot3-starter` dependency brings in the annotation JAR
- `PageResult<T>` DTO wraps MyBatis-Plus `IPage` for clean Jackson serialization across the HTTP boundary
- Client uses BootstrapFX (`org.kordamp.bootstrapfx:bootstrapfx-core:0.4.0`) for UI styling