Microservices communication in Spring Boot with Feign client
Communicate two microservices with HTTP protocol
Microservices is one of those architectural patterns which has emerged from the world of domain-driven design, and its many applications communicate with each other to form a complete application. The common protocol used for that reason is Http/Https. By the end of this article, you will learn how to communicate microservices in a Spring Boot application using Feign — a declarative HTTP client developed by Netflix.
I assume that you have already two microservices(if not you will find the source code below), so I will jump directly to implementation. For this example, I two microservices(one is a UserServiceApp second is an ItemServiceApp).
I will create a service that calls a list of user items in ItemServiceApp.
To use Feign, we need to add the needed dependencies:
For the latest version, check Here.
Then add @EnableFeignClients annotation in the main Application.class
In ItemsServiceApp there is an API that fetches a list of items by user ID.
Now to consume this in UserServiceApp, we need an Interface service and add @FeignClient annotation with the name of the microservice defined in application.properties
The path value in @GetMapping is the path of the API in ItemsServiceApp.
The service will look like that:
Now, we can call the getItemByUserId() method in UserService.
That is all, not that complicated, right!
If you face any problem, please write it in the comment.
Resources:
https://spring.io/projects/spring-cloud-openfeign
Source code: here
