October 21, 2022
Category: Building Modern Web Apps with Spring
I’ve been excited about this one for a while. With the release of Spring Boot 3 and Java 17 LTS, building modern, performant, and maintainable web applications has never been smoother. This post is your quickstart guide to get your first Spring Boot 3 app up and running on Java 17.
Why Spring Boot 3 and Java 17?
Java 17 is the latest Long-Term Support (LTS) release, offering improved language features, better performance, and long-term stability. Spring Boot 3 is the natural evolution of the popular Spring Boot framework, designed to take full advantage of Java 17 and the new Jakarta EE 9 namespaces we talked about previously.
The two combined give you:
- Access to new Java language features like sealed classes, pattern matching, and records.
- Improved startup and runtime performance.
- Native compilation support (via Spring Native/AOT).
- Support for modern APIs and cloud-native architectures.
Setting Up Your Project
Start with the Spring Initializr (https://start.spring.io/):
- Select Spring Boot 3.x.
- Choose Java 17 as the language version.
- Pick your favorite build tool (Maven or Gradle).
- Add dependencies like Spring Web, Spring Data JPA, and Spring Security as needed.
Download the generated project, unzip it, and open it in your IDE.
Your First Application
In the main class:
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}Run the app via your IDE or ./mvnw spring-boot:run (or ./gradlew bootRun).
Exploring New Java 17 Features in Spring Boot Apps
Leverage records for immutable DTOs:
public record UserDto(Long id, String name, String email) {}Use pattern matching to simplify your conditional logic:
if (obj instanceof User user) {
System.out.println(user.name());
}And sealed classes to define strict class hierarchies for domain models.
Next Steps
- Add REST controllers with Spring Web.
- Integrate a database using Spring Data JPA.
- Secure endpoints with Spring Security 6.
- Monitor health and metrics using Spring Boot Actuator.
Final Thoughts
Spring Boot 3 paired with Java 17 is a solid foundation for modern Java development. The framework embraces the latest Java features and Jakarta EE 9, helping you write cleaner, faster, and more maintainable code.
In upcoming posts, we’ll explore Building Reactive Web Apps with Spring WebFlux and Best Practices for REST APIs with Spring Boot, so stay tuned!
Have you tried Spring Boot 3 with Java 17 yet? What’s your favorite new feature so far? Drop a comment below!
