In-depth analysis of Spring Boot, Spring MVC and Spring Cloud

Foreword

Spring Boot, Spring MVC and Spring Cloud are three very important frameworks in Java enterprise development. They each have different capabilities, but can also be used together to create powerful and scalable applications.

• foreword
• • Spring Boot: Simplifying Spring Application Development
  • Spring MVC: Web Application Development Framework
  • Spring Cloud: Microservice Architecture
  • In conjunction with

Spring Boot: Simplify Spring Application Development

Spring Boot was created to simplify Spring application development. It uses a “convention over configuration” approach, allowing developers to focus more on writing business logic instead of spending a lot of time on configuration files. Spring Boot provides many default configurations, such as embedded Tomcat and auto-configured Spring context.

Spring Boot also provides the concept of starters (Starters), through which you can easily add and manage your project dependencies. For example, if you need to add Spring MVC to your project, you only need to add the dependency of spring-boot-starter-web.

Spring Boot example

// Import the dependencies required by Spring Boot
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication // Indicates that this is a Spring Boot application
public class DemoApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(DemoApplication.class, args); // Start the Spring Boot application
    }
}

Spring MVC: Web Application Development Framework

Spring MVC, part of Spring, is a framework for developing web applications. Spring MVC simplifies the process of web development by using annotations. You can use the @Controller annotation to create a controller, use the @RequestMapping annotation to define routing rules, and use @RequestParam, @PathVariable and other annotations to obtain request parameters.

Spring MVC also supports RESTful-style Web services, and you can use the @RestController annotation to create RESTful APIs. By combining Spring Boot, you can quickly develop a Spring MVC application.

Spring MVC Example

// Import the dependencies required by Spring MVC
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller // Indicates that this is a Spring MVC controller
public class DemoController {<!-- -->
    @GetMapping("/hello") // Map GET request to /hello
    @ResponseBody // Indicates that the returned string is written directly into the HTTP response body
    public String hello() {<!-- -->
        return "Hello, Spring MVC!";
    }
}

Spring Cloud: Microservice Architecture

Spring Cloud is a set of micro-service solutions, providing a distributed system (such as configuration management, service discovery, circuit breaker, intelligent routing, micro-agent, control bus, one-time token, global lock, decision-making campaign, distributed session and cluster state, etc.) implementations of common patterns. Using Spring Cloud, developers can quickly build some common microservice patterns.

For example, Spring Cloud Config provides server and client support for external configuration in distributed systems. Spring Cloud

Netflix includes the encapsulation of multiple Netflix OSS components, including Eureka, Hystrix, Zuul, Ribbon, etc.

Spring Cloud Examples

Suppose we want to use Eureka for service discovery. First, we need to create a Eureka server:

// Import the dependencies required by Spring Cloud Eureka
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer // Indicates that this is a Eureka server
public class EurekaServerApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(EurekaServerApplication.class, args); // Start the Eureka server
    }
}

Then, we can create a service provider and register it with the Eureka server:

// Import the dependencies required by Spring Cloud Eureka Client
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient // Indicates that this is a Eureka client, that is, a service provider
@RestController
public class ServiceProviderApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(ServiceProviderApplication.class, args); // Start the service provider
    }

    @GetMapping("/hello")
    public String hello() {<!-- -->
        return "Hello, Spring Cloud!";
    }
}

Use in combination

Spring Boot, Spring MVC and Spring Cloud can be used in combination to build a complete microservice architecture. Use Spring Boot and Spring MVC for rapid development to create microservices with RESTful APIs. Then use the functions of Spring Cloud, such as service registration and discovery, configuration center, API gateway, etc., to manage microservices.

With such an architecture, you can easily add new microservices and extend the functionality of your application. Each microservice can be developed, deployed and expanded independently, with a high degree of decoupling. At the same time, you can also use the service governance capabilities provided by Spring Cloud to efficiently manage microservices.

Here is an example on how to use Spring Boot, Spring MVC and Spring Cloud together:

In this example, we will create a simple microservice architecture, including a service registry, a service provider, and a service consumer.

Service Registry

First, we need to create a service registry using Spring Cloud Eureka.

// Import the dependencies required by Spring Cloud Eureka Server
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer // Indicates that this is a Eureka server
public class EurekaServerApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(EurekaServerApplication.class, args); // Start the Eureka server
    }
}

Service Provider

Then, we create a service provider. This service provider will be created using Spring Boot and Spring MVC, and registered with the service registry using Spring Cloud Eureka Client.

// Import the dependencies required by Spring Cloud Eureka Client and Spring MVC
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient // Indicates that this is a Eureka client, that is, a service provider
@RestController
public class ServiceProviderApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(ServiceProviderApplication.class, args); // Start the service provider
    }

    @GetMapping("/hello")
    public String hello() {<!-- -->
        return "Hello, Spring Cloud!";
    }
}

Service Consumer

Finally, we create a service consumer. This service consumer will also be created using Spring Boot and Spring MVC, while using Spring Cloud Eureka Client to discover services from the service registry.

// Import dependencies required by Spring Cloud Eureka Client, Spring MVC and RestTemplate
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import org.springframework.beans.factory.annotation.Autowired;

@SpringBootApplication
@EnableEurekaClient // Indicates that this is a Eureka client, that is, a service consumer
@RestController
public class ServiceConsumerApplication {<!-- -->
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(ServiceConsumerApplication.class, args); // Start the service consumer
    }

    @Autowired
    private RestTemplate restTemplate;

    @GetMapping("/hello")
    public String hello() {<!-- -->
        // Call the interface of the service provider through RestTemplate
        return restTemplate.getForObject("http://service-provider/hello", String.class);
    }
}

Through the above three steps, we have created a simple microservice architecture. Each service can be developed, deployed and expanded independently, with a high degree of decoupling. At the same time, through the service registration center, service consumers can automatically discover service providers, realizing automatic management between services.

The above is a brief introduction and code example about Spring Boot, Spring MVC and Spring Cloud. I hope it can be helpful to your study and work. In the actual development process, you need to flexibly use these three tools according to your business needs to improve development efficiency and reduce development difficulty.