Difference between Spring Cloud and Spring Boot

1. Introduction

Spring Boot and Spring Cloud are frameworks within the larger Spring ecosystem that facilitate the development of stand-alone and cloud-based applications respectively. Spring Boot is focused on simplifying the development of stand-alone Spring applications, whereas Spring Cloud is focused on providing tools to quickly and easily build some of the common patterns in distributed systems.

2. Key Points

1. Spring Boot is designed to simplify the bootstrapping and development of new Spring applications.

2. Spring Cloud is designed to simplify the integration of common distributed system patterns into Spring Boot applications.

3. Spring Boot takes an opinionated view of the Spring platform to minimize configuration and setup.

4. Spring Cloud builds on Spring Boot and provides tools to implement patterns like configuration management, service discovery, circuit breakers, and intelligent routing.

3. Differences

Spring Boot	Spring Cloud
Simplifies creating stand-alone, production-grade Spring-based applications easily.	Provides tools for developers to quickly build common patterns in distributed systems.
Focuses on ease of development, microservice-ready, and standalone deployment.	Focuses on providing a coherent distributed system experience for configuration, service discovery, and more.
Great for creating microservices that run independently.	Great for managing, connecting, and securing microservices.

4. Example

// Spring Boot application example
@SpringBootApplication
public class SpringBootService {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootService.class, args);
    }
}

// Spring Cloud application example with a service discovery client
@SpringBootApplication
@EnableDiscoveryClient
public class SpringCloudService {
    public static void main(String[] args) {
        SpringApplication.run(SpringCloudService.class, args);
    }
}

Output:

// There is no direct output from these code snippets. They illustrate the foundational code to bootstrap Spring Boot and Spring Cloud applications.

Explanation:

1. The SpringBootService application will be a standalone application with an embedded server and minimal configurations.

2. The SpringCloudService application is set up for service discovery, making it ready to be a part of a microservice ecosystem.

5. When to use?

- Use Spring Boot to create microservices that can run on their own with little to no additional configuration.

- Use Spring Cloud when building distributed systems and you need support for patterns like configuration management, service discovery, circuit breakers, etc.