Getting Started with Spring Boot 3

Spring Boot makes it easy to create stand-alone, production-grade Spring applications. In this guide, we'll create our first application using Java 21 and Spring Boot 3.

Prerequisites

Before we begin, make sure you have:

Java 21 or later installed
Maven or Gradle
Your favorite IDE (IntelliJ IDEA recommended)

Creating Your First Application

The easiest way to start is using Spring Initializr. You can also create the project manually:

java

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

Creating a REST Controller

Let's create a simple REST endpoint:

java

@RestController
@RequestMapping("/api")
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello, Spring Boot 3!";
    }

    @GetMapping("/hello/{name}")
    public String helloName(@PathVariable String name) {
        return "Hello, " + name + "!";
    }
}

Running the Application

Run your application using:

bash

./mvnw spring-boot:run

Then visit http://localhost:8080/api/hello in your browser.

Next Steps

Learn about dependency injection
Explore Spring Data JPA for database access
Add security with Spring Security