# Game Platform Server (Spring Boot WebFlux + MyBatis + MySQL)

A minimal backend scaffold using Spring Boot 3, WebFlux, MyBatis, and MySQL. Includes a sample `User` CRUD implemented via MyBatis (blocking JDBC) safely wrapped in reactive APIs.

## Tech Stack

- Spring Boot 3 (WebFlux, Actuator)
- MyBatis Spring Boot Starter (JDBC)
- MySQL Connector/J
- Java 17

## Blocking JDBC with WebFlux

MyBatis uses JDBC which is blocking. To keep WebFlux event loop non-blocking, all data access is offloaded to `Schedulers.boundedElastic()` (see `UserService`). This is a common and safe pattern when you need WebFlux endpoints but must use JDBC/MyBatis.

## Project Layout

- `pom.xml` – Maven build, dependencies
- `src/main/resources/application.yml` – datasource + mybatis config
- `src/main/resources/mapper/*.xml` – MyBatis mappers (XML)
- `src/main/resources/schema.sql` – initial table
- `src/main/java/com/gameplatform/server` – application code

## Configure Database

1. Create database:
   ```sql
   CREATE DATABASE game_platform CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
   ```
2. Update `spring.datasource.*` in `application.yml` with your MySQL credentials.
3. Run the SQL init:
   ```sql
   USE game_platform;
   -- then execute contents of src/main/resources/schema.sql
   ```

## Build & Run

Requires JDK 17+ and Maven 3.9+.

```bash
mvn spring-boot:run
```

The app starts on `http://localhost:8080`.

## Endpoints

- `GET /actuator/health` – health check
- `GET /api/users` – list users
- `GET /api/users/{id}` – get user by id
- `POST /api/users` – create user
  - body:
    ```json
    {"username": "alice", "email": "alice@example.com"}
    ```
- `DELETE /api/users/{id}` – delete user

## Notes

- If you need true end-to-end reactive IO, consider R2DBC instead of JDBC/MyBatis. Here we keep MyBatis for mapping convenience and use bounded elastic threads to avoid blocking the event loop.