Whether you are new to Spring or a seasoned developer, Spring Boot's opinionated defaults and powerful tools make it an excellent choice for creating robust and scalable applications.

Before diving into the setup, ensure you have the following prerequisites:

• Java Development Kit (JDK) 8 or higher installed on your system
• An Integrated Development Environment (IDE) like IntelliJ IDEA, Eclipse, or VS Code
• Maven or Gradle installed for dependency management

With these tools ready, let's start building your first Spring Boot application.

Spring Initializr is an online tool provided by the Spring community to quickly generate a Spring Boot project. You can access it at start.spring.io. Follow these steps:

1. Select the project type (Maven or Gradle) and language (Java, Kotlin, or Groovy).
2. Choose the latest stable version of Spring Boot.
3. Fill in the Group and Artifact fields. For example:
   Group: com.example
   Artifact: demo
4. Add dependencies. For a basic web application, include Spring Web.
5. Click the Generate button to download the project as a ZIP file.

After downloading, unzip the project and open it in your preferred IDE.

Spring Boot applications include an application.properties or application.yml file for configuration. Here's a simple example of a application.properties file:

server.port=8081
spring.application.name=DemoApplication

This configuration sets the application's name to DemoApplication and changes the default port to 8081.

Create a simple REST endpoint by following these steps:

1. Create a new Java class called HelloController.
2. Annotate the class with @RestController to indicate it handles web requests.
3. Add a method that returns a greeting message:

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

@RestController
public class HelloController {

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

To run the application, navigate to the project's root directory and use the following command:

mvn spring-boot:run

If you are using Gradle, run:

./gradlew bootRun

Once the application starts, open your web browser and navigate to http://localhost:8081. You should see the message Hello, Spring Boot!.

To package your application into a standalone JAR file, use the following command for Maven:

mvn clean package

This will create a JAR file in the target directory. You can run the JAR file using:

java -jar target/demo-0.0.1-SNAPSHOT.jar

Spring Boot applications come with several powerful features to enhance your development experience:

• Embedded Servers: Includes Tomcat, Jetty, or Undertow for running web applications without additional setup.
• Auto-Configuration: Automatically configures your application based on the dependencies present.
• Actuator: Provides endpoints for monitoring and managing the application.

Spring Boot simplifies the process of setting up and running a Java application. With its wide range of features and robust ecosystem, you can build production-ready applications in no time. This tutorial is just the beginning; there are many more advanced topics to explore as you continue your Spring Boot journey.