To call one microservice from another using Spring Boot, you can utilize the Spring Cloud ecosystem and its features for service discovery and communication. Here’s a general guide on how to achieve this:

1. Set up the Spring Cloud Config Server (optional):
   If you haven’t already, you can set up a Spring Cloud Config Server to manage the configuration of your microservices centrally. This server will provide the configuration details needed for the microservices to communicate with each other.
2. Enable service discovery:
   Service discovery allows microservices to locate and communicate with each other without hardcoding their network locations. Spring Cloud provides a service discovery solution called Netflix Eureka.

• Add the necessary dependencies to your microservice’s pom.xml file:

 
org.springframework.cloud 
spring-cloud-starter-netflix-eureka-client 

• Enable the Eureka client in your microservice’s main class by adding the @EnableDiscoveryClient annotation:

import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableDiscoveryClient
public class YourMicroserviceApplication {
    public static void main(String[] args) {
        SpringApplication.run(YourMicroserviceApplication.class, args);
    }
}

1. Make RESTful calls between microservices:
   With service discovery enabled, you can make RESTful API calls from one microservice to another. Spring provides a convenient way to communicate with RESTful services using the RestTemplate or WebClient classes.

• Add the necessary dependencies to your microservice’s pom.xml file (depending on the chosen HTTP client):

    org.springframework.boot
    spring-boot-starter-web




    org.springframework.boot
    spring-boot-starter-webflux

• Use RestTemplate or WebClient to make HTTP calls to the desired microservice. Here’s an example using RestTemplate:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class YourController {
    private final RestTemplate restTemplate;

    @Autowired
    public YourController(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    @GetMapping("/your-endpoint")
    public String yourEndpointMethod() {
        String url = "http://microservice-name/endpoint"; // Replace with the appropriate URL of the target microservice
        String response = restTemplate.getForObject(url, String.class);
        return response;
    }
}

1. Configure the target microservice’s name:
   In the previous example, microservice-name should be replaced with the actual name of the target microservice. When using Eureka, microservices register themselves with unique names, and Eureka’s service discovery mechanism resolves those names to the corresponding network locations. To configure the target microservice’s name, you can either use the microservice’s application name (specified in its application.properties or application.yml) or use the actual hostname and port of the microservice instance.

That’s it! With service discovery and RESTful communication established, your microservice can call another microservice using Spring Boot and the Spring Cloud ecosystem. Remember to configure the necessary

Happy Learning.