/rest-messaging-db

Primary LanguageJava

rest-messaging-db

Those 3 Application interact each other with different way of communication to simulate very simple microservice.

  • We have REST API with method GET and POST which sending sample Product data.
  • We have Database (MySQL) with INSERT and QUERY
  • We have Messaging (RabbitMQ) complete with PUBLISH and CONSUME

Sequence Diagram

Rest API and Messaging flow

Demo Apps

https://www.youtube.com/watch?v=yaLzOAycYhM

Frontend Service

Since a backend server apps does not have "physical button" like a user interface, so i use a simple API to trigger another API.

This Frontend service only used for simplify the testing process by triggering other 2 API service in Producer and Consumer service. For triggering it you can use browser or curl or postman.

This service expose 2 API

  • GET http://localhost:8080/send-data. It will call POST http://localhost:8081/products to send product to Producer Service
  • GET http://localhost:8080/get-data. It will call GET http://localhost:8082/products to get product from Consumer Service

Currently run on port 8080. To change the port you can refer to frontend/src/main/resources/application.properties

run it by

$ cd frontend/
$ mvn spring-boot:run

Producer Service

In this Service, we will see how to sending message event to message broker (RabbitMQ).

Before runnning this service, make sure you already run the RabbitMQ. If you have a docker, you can just run docker-compose up from docker/ directory

This Service have 2 API

  • POST http://localhost:8081/products This REST API will be called by Frontend Service to publish data product to the message broker
  • GET http://localhost:8081/hello This api only for demonstrate sending different event to the Consumer Service. It will only send simple "hello" message. This API can directly called via browser / curl / postman

Currently run on port 8081. To change the port you can refer to producer/src/main/resources/application.properties

run it by

$ cd producer/
$ mvn spring-boot:run

Consumer Service

This service show how to consume a message from messagebroker (RabbitMQ). All the messagebroker configuration is defined in consumer/com/mirzaakhena/consumer/config/RabbitConfig.java. From the config, you can see and learn how to setup 1 exchange, 2 different queue, and binding all together to work with this RabbitMQ message broker.

This service has 1 API that will called by Frontend Service

  • GET http://localhost:8082/products is a REST API to get (read/query) product data from database

This service has 2 subscribed event

  • product_event. This event will store (save/insert) product data to database
  • hello_event. This event will trigger outputing hello message to console.

Currently run on port 8082. To change the port you can refer to consumer/src/main/resources/application.properties. From the config, you can see and learn about how to setup config to working with MySQL database.

To run this service you have to make sure your MySQL is running. Otherwise you will fail to run it. No need to setup any database or table. Spring boot will automatically create it for you. Just be aware about the database user and password.

Hello event is for demonstrating the ability of consumer to listen multiple event, since we already have a product event.

run it by

$ cd consumer/
$ mvn spring-boot:run