Spring Boot Micro Services with Gradle

RESTful web services are the first step to developing great microservices. Spring Boot, in combination with Spring Web MVC (also called Spring REST) makes it easy to develop RESTful web services.
Here we will learn the basics of Microservices from scratch and will understand how to implement microservices using Spring Cloud.

APIs used to get country details

https://restcountries.eu/rest/v2/name/India - Get country details by name
https://restcountries.eu/rest/v2/name/japan - Get country details by name
https://restcountries.eu/rest/v2/currency/INR - Get country details by currency

You will learn

• You will be able to develop and design RESTful web services
• You will setup Centralized Microservice Configuration with Spring Cloud Config Server
• You will learn to register Eureka Client applications with Eureka Server
• You will learn how to implement Circuit breaker for fault tolerance using Hystrix
• Consume Third party API using RestTemplate and WebClient
• Load Balance using Ribbon for RestTemplate and WebClient
• You will learn declarative web service HTTP client with the help of Feign
• You will be able to consume and communicate other RESTful web services using Ribbon and Feign
• You will understand how to monitor RESTful Services with Spring Boot Actuator
• You will understand the best practices in designing RESTful web services

Prerequisites

• Java (Java 8)
• Spring Boot
• Gradle

Tools

• Eclipse or IntelliJ IDEA (or any preferred IDE) with embedded Gradle
• Gradle (version >= 6.0)
• Postman (or any RESTful API testing tool)

Modules / Sub-modules

Name	Port	Description
spring-boot-microservices-gradle(root)	(Root/Parent module)
common-country-client	8300, 8301,.. (or dynamic random port)
common-model
country-config-server	8888 (optional)
country-currency-webclient-client	8200, 8201,.. (or dynamic random port)
country-details-restful-client	8100, 8101,.. (or dynamic random port)
eureka-naming-server	8761
ribbon-feign-client	8000
zuul-api-country-details	8090

You can dynamically run multiple instances for restful-client and webclient-client applications by changing ports as shown above
Each instance will get registered under Eureka Server and urls will be mapped respectively.

Build with Gradle

GOTO > ~/absolute-path-to-directory/spring-boot-microservices-gradle/
and try below command in terminal

gradle clean build it will build all sub-modules from parent module

If in case face any issue while building modules because of test cases, then try build with disabling test cases

gradle clean build -x test

Order to Run the Applications

1. eureka-naming-server
2. country-config-server (optional)
3. country-currency-webclient-client
4. country-details-restful-client
5. common-country-client
6. ribbon-feign-client
7. zuul-api-country-details

Under each module you will find *Aplication.java class, run main() method from that class

API Endpoints

Name	URL
eureka-naming-server	http://localhost:8761
common-country-client	http://localhost:8300/india or {random.port}
country-config-server	http://localhost:8888
country-currency-webclient-client	http://localhost:8200 or {random.port}, http://localhost:8201 or {random.port},...
country-details-restful-client	http://localhost:8100 or {random.port}, http://localhost:8101 or {random.port},...
ribbon-feign-client	http://localhost:8000
zuul-api-country-details	http://localhost:8090/common-country-client/india