## Java Implementation  

#### 运行方式

用./mvnw spring-boot:run运行
h2 database在 localhost:8080/h2-console

#### cURL测试

用cURL测试/api/v1/product/create
curl -X POST -H "Content-Type: application/json" --data '{"name":"product1","price":"1.0","stock":"5"}' http://localhost:8080/api/v1/product/create
返回
{"code":201,"name":"product1","message":"Product created"}

再次用cURL测试/api/v1/product/create使用相同的name
返回
{"code":409,"message":"Product with the same name already exists"}

用cURL测试/api/v1/product/{id}
curl -X GET -H "Content-Type: application/json" http://localhost:8080/api/v1/product/product1
返回
{"product":{"price":1.0,"name":"product1","stock":5},"code":200,"message":"Product retrieved"}
用cURL测试/api/v1/product/{id}使用不存在的name
返回
{"code":404,"message":"Product not found"}

#### 代码结构
- controller: 接受请求parameters然后调用service
- service: 调用repository，处理业务逻辑。在必要时throw exception
- repository: 继承JpaRepository，和database交互存储数据
- product: Model class
controller不直接调用repository,而是调用service负责业务逻辑。将来如要更改实现方式，只需更改service和repository，不用更改controller