Sandbox

This application provides skeleton for starting new projects with a lot of boilerplate code. In this project used Clean\Onion Architecture. As an example used ItemEntity as a base Domain model, backed by Repository, Service and Rest Controller, validation, logging. Tests written for each layer - Repository, Service, Controller and Integration tests for the whole application.

Technology stack

• Maven
• Spring Boot 3
• Postgres Database
• Docker | Docker Compose
• Flyway
• MapStruct
• Lombok
• Swagger
• JUnit | Mockito | MockMvc | Testcontainers

REST API

Endpoint	Method	Req. body	Status	Resp. body	Description
/api/v1/items	GET		200	ItemDTO[]	Get all the items
/api/v1/items	POST	ItemDTO	201	ItemDTO	Add a new item
/api/v1/items/{id}	GET		200	ItemDTO	Get the item with the given ID.
			404	ErrorDTO	No item with the given ID exists.
/api/v1/items/{id}/{locale}	GET		200	LocalizedItemDTO	Get the localized item with the given ID and Locale.
			404	ErrorDTO	No item with the given ID exists.
/api/v1/items/{id}	PUT	ItemDTO	200	ItemDTO	Update the item with the given ID.
			404	ErrorDTO	No item with the given ID exists.
/api/v1/items/{id}	DELETE		204		Delete the item with the given ID.

Swagger UI is available.

Useful Commands

Maven Command	Description
mvn spring-boot:run	Run the application.
mvn clean install	Build the application.
mvn clean test	Run tests.

Running a PostgreSQL Database

Run PostgreSQL as a Docker container

docker run -d \
--name sandbox-postgres \
-e POSTGRES_USER=user \
-e POSTGRES_PASSWORD=password \
-e POSTGRES_DB=sandbox_db \
-p 5432:5432 \
postgres:14.4

or run via Docker Compose

cd docker
docker-compose up

Container Commands

Docker Command	Description
docker stop sandbox-postgres	Stop container.
docker start sandbox-postgres	Start container.
docker remove sandbox-postgres	Remove container.

Database Commands

Start an interactive PSQL console:

docker exec -it sandbox-postgres psql -U user -d sandbox_db

PSQL Command	Description
\list	List all databases.
\connect sandbox_db	Connect to specific database.
\dt	List all tables.
\quit	Quit interactive psql console.

Internationalization (i18n)

Data localization

In a case you need translated or adjusted response according to the certain location, there is an example with translated currency code by requested locale on the /api/v1/items/{id}/{locale} endpoint. It translates Entity field currencyCode with the most matching locale among those present in ResourceBundle files in the src/main/resources/resourcebundle directory.

Exception localization

For translation of REST request arguments validation messages, there is a ValidationExceptionHandler class that handles
MethodArgumentNotValidException type exceptions and translates its messages by the language header. Validation happens before the REST controllers method invocation.

Spring Actuator

The following Spring Actuator endpoints are used for monitoring application state and retrieving the corresponding data:

• /actuator Use this endpoint to get a list of all endpoints enabled in Spring Actuator.
• /actuator/health Use this endpoint to get the basic health information about the application.
• /actuator/metrics Use this endpoint to get a list of available application metrics.
• /actuator/metrics/{MetricName} Use this endpoint to receive data from the specific metric.
• /actuator/info Use this endpoint to display the application-specific information.
• /actuator/httpexchanges Use this endpoint to get traces of all the HTTP requests have been processed by the application.
• /actuator/flyway Use this endpoint to get details about the Flyway database migrations.
• /actuator/beans Use this endpoint to get all available beans created by the application.

Authentication

The application utilizes the Basic HTTP authentication. It requires the Authorization: Basic header followed by the login:password pair to be included in all requests made to the application. The login and password are specified in the credentials.properties file.

To disable the authentication for the entire application, use the app:security:enabled property of the application.yml.

Note, that the login:password pair used in the authorization header should be encoded in base64 format:

### Get all itemsGET http://localhost:8081/actuatorAuthorization: Basic dXNlcjpwYXNzd29yZA==