Building Scalable Microservices with Spring Boot and Spring Cloud

1. Introduction to Microservices Architecture

What are Microservices?

Microservices is an architectural style where an application is built as a collection of small, loosely coupled services that communicate over APIs. Each service handles a specific business capability.

Benefits:

• Scalability: Services can scale independently.
• Flexibility: Different technologies for each service.
• Faster development: Parallel development by separate teams.

Challenges:

• Complexity: Increased operational complexity.
• Data consistency: Difficult due to distributed nature.
• Service communication: Requires effective inter-service calls.

2. Creating a Microservice with Spring Boot

2.1. Project Setup with Spring Initializr

Dependencies:

• Spring Web
• Spring Boot DevTools
• Spring Cloud Config
• Spring Data JPA
• Eureka Client

2.2. Creating a RESTful Microservice

Example: ProductService

@RestController
@RequestMapping("/api/products")
public class ProductController {

@Autowired
    private ProductService productService;
    @GetMapping
    public List<Product> getAllProducts() {
        return productService.findAll();
    }
}

Best Practice: Use DTOs to avoid exposing internal entities.

3. Service Discovery with Eureka

3.1. Setting up Eureka Server

Add dependency:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

Enable Eureka Server:

@EnableEurekaServer
@SpringBootApplication
public class…