Introduction to Spring Boot

Overview of the Spring Framework and its ecosystem

• The Spring Framework is a popular Java framework for building enterprise-level applications.

• It provides a comprehensive ecosystem of libraries and modules for various purposes, such as web development, data access, security, and more.

Introduction to Spring Boot and its features:

• Spring Boot is a sub-project of the Spring Framework that aims to simplify the development of Spring applications.

• It provides a convention-over-configuration approach, reducing boilerplate code and configuration.

• Spring Boot includes features like auto-configuration, embedded servers, and production-ready metrics, making it easy to build robust applications.

Setting up a Spring Boot development environment:

1. Install Java Development Kit (JDK) 8 or higher.

2. Download and install an Integrated Development Environment (IDE) such as Eclipse, IntelliJ IDEA, or Spring Tools Suite.

3. Create a new Spring Boot project using the Spring Initializr (https://start.spring.io) or your IDE's Spring Boot project template.

Creating and running a simple Spring Boot application:

1. Create a new Java class, for example, HelloWorldApplication.

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class HelloWorldApplication {

    public static void main(String[] args) {
        SpringApplication.run(HelloWorldApplication.class, args);
    }
}

1. Create a REST controller to handle HTTP requests and return a response.

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloWorldController {

    @GetMapping("/hello")
    public String sayHello() {
        return "Hello, World!";
    }
}

1. Run the application by executing the main method in the HelloWorldApplication class.

2. Open a web browser and navigate to http://localhost:8080/hello. You should see the message "Hello, World!" displayed.

Congratulations! You have successfully created and run a simple Spring Boot application.

Note: The code snippets provided here are simplified examples for demonstration purposes. In a real-world application, you would typically have more complex configurations, business logic, and additional components.