User Microservice

This microservice handles basic user management, following industry-standard best practices such as Domain-Driven Design (DDD), Clean Architecture, SOLID principles, and automated tests. The microservice serves as an illustrative example of how clean and dependency-free domain-driven Java applications can be developed.

Features

• User registration with the following fields:
  • ID
  • Name
  • Email
• Domain validation and business logic encapsulation.
• Domain layer without external dependencies.
• Automated unit and integration tests.
• After creating a user, the microservice publishes an event to an Apache Kafka topic indicating that the user was successfully created.

Database

• Currently using an in-memory H2 database for simplicity and easy demonstration purposes.

Kafka Integration

• Once a user is created, an event is published to the Kafka topic users, informing other services that a user has been successfully created.
• Kafka Topic: The topic must currently be created manually.

Build and Run

Build

./mvnw clean package

Run (Spring Boot plugin)

./mvnw spring-boot:run

Run (Executable JAR)

java -jar target/user-service.jar

Testing and Coverage

Run tests

./mvnw clean test

Generate test coverage report (JaCoCo)

./mvnw jacoco:report

The coverage report will be generated at:

target/site/jacoco/index.html

Notes

• PostgreSQL implementation is planned, but currently, the service uses an in-memory H2 database.
• Java 21 and Spring Boot 3.2.3 are the base technologies currently in use.

Dependencies

• Java 21
• Spring Boot 3.2.3
• Apache Kafka
• H2 Database (In-memory)
• Maven (via wrapper)
• JaCoCo (test coverage reporting)

Specific version numbers will be updated or adjusted as development continues.

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COMMENTS:

• Dominio e application isolados de framework
• pasta config configurando o framework
• Pricipios do DDD como value object, aggregate root, entity, domain event com classes bases
• Validatations no domain
• Exceptions personalizadas
• Inversao de dependencias com interfaces para isolar o dominio (usecases) de libs externas
• Disparando Eventos na criacao de usuarios
• Paginacao personalizada
• spring configurations and annotations on the config and presentation layer
• usando tester do spring ( é o Junit? ) TODO:
• Continuar app mesmo com erro no kafka ou handle errors
• Criar uma interface para usecases
• Falar que poderia ter um tratamento de erro mais robusto devolvendo todos os erros de uma vez só
• Criar exceptions de required e missed mais detalhadas
• Ter uma classe de uniqueUUID
• Profile em PROD
• Profile de testes
• Add a prod DB
• correct config log e em prod
• improve domain events - more rich
• domain->entity -> testar quando é passado dates para entity

TESTS:

• melhorar os testes do entry point
• Testar melhor o controller com mock
• checar o e2e
• colocar testes em paralelo
• testar kafa