Reactive MicroServices Example

info

This is an example of doing reactive MicroServices using spring 5 functional web framework and spring boot 2.

This service provide and API that will greet the user with a quote.

This example cover several topics:

• Functional programing.
• Reactive types.
• Router Functions.
• Static Web-Content.
• Creation on Reactive Java Services/Components.
• Error handling in routes and services.
• Reactive Web Client to consume external REST Services.
• Organizing your project in manageable packaging.

Includes and in depth look to testing using JUnit5:

• Unit, Integration and System tests.
• Mocking, including reactive functions.
• BDD style assertions.
• Test tags with maven profiles.

usage

To run this service:

$ mvnw spring-boot:run

Sample requests

• GET http://localhost:8080/api/greetings

• GET http://localhost:8080/api/greetings/reactive

• POST http://localhost:8080/api/greetings

  {
      "name" : "json"        
  }

API

Run the API via the embedded Swagger UI

Project Structure

• main/java
  • /application : Main Spring boot application and context configuration.
  • /routers : Reactive routing functions.
  • /handlers : Handlers used by the routers.
  • /services : Services for the business logic needed by handlers.
  • /exceptions : Businesses exceptions.
  • /model : POJOs.
• test/java:
  • /application : Application system tests.
  • /routers : Integration tests for routes.
  • /handlers : Unit tests for handlers.
  • /services : Unit tests for services.
  • /categories : Tests categories.
  • /model : POJOs used by the test.
  • /test : Helpers and base classes for testing.

References

• https://spring.io/blog/2016/09/22/new-in-spring-5-functional-web-framework
• https://spring.io/blog/2017/02/23/spring-framework-5-0-m5-update
• http://junit.org/junit5/docs/current/user-guide/#running-tests-build-maven
• https://github.com/junit-team/junit5-samples
• http://quotesondesign.com/