Spring Boot 3.0+: A Deeper Dive into the Cutting Edge of Java Development

Naveen Metta
4 min readFeb 26, 2024
credit goes to the owner : https://javatechonline.com/new-features-in-spring-boot-3-and-spring-6/
source : javatechonline.com

Spring Boot 3.0, released in November 2022, wasn’t just a minor update; it was a paradigm shift for Java development. This major upgrade boasts a plethora of new features, performance optimizations, and foundational changes that catapulted Spring Boot to a whole new level. Let’s delve deeper into the key highlights and explore their implications in detail:

Java 17 Baseline:

What it means: Spring Boot 3.0 requires Java 17 or higher. This isn’t just a formality; it unlocks a treasure trove of benefits:

Improved performance: Java 17 introduces Switch expressions with sealed classes, allowing for concise and efficient control flow. Additionally, improved garbage collection algorithms and optimizations lead to faster startup times and better memory management.

Enhanced null safety: With records and non-null assertions, you can write code with more confidence, reducing the risk of null pointer exceptions. No more null checks cluttering your code!

Modern features: Records bring a functional and concise way to define data structures, while pattern matching enhances readability and maintainability.

Benefits: You’ll experience faster, more reliable, and modern applications without writing a single line of boilerplate code.

Jakarta EE 9 Integration:

What it means: Spring Boot 3.0 embraces Jakarta EE 9, the successor to Java EE. This brings standardized APIs for web development, enterprise features, and improved security:

Simplified development: Jakarta EE 9 provides a consistent API across different vendors, making it easier to switch between implementations. No more vendor lock-in!

Modern security: Jakarta EE 9 includes robust security features like OAuth 2.0 and OpenID Connect, simplifying user authentication and authorization.

Future-proofing: By adopting the latest standard, you ensure your application is compatible with future advancements in the Java ecosystem.

Benefits: You gain faster development, robust security, and future-proof applications, all thanks to standardized APIs and modern features.

Observability with Micrometer and Micrometer Tracing:

What it means: Spring Boot 3.0 introduces “Spring Observability,” a powerful initiative leveraging Micrometer and Micrometer Tracing. This simplifies collecting application metrics and tracing distributed transactions:

Micrometer: This library provides a unified API for collecting metrics across different tools and technologies. No more vendor-specific code!

Micrometer Tracing: This extension enables tracing distributed transactions, offering valuable insights into how your application behaves across different systems.

Benefits: You gain detailed insights into application performance, troubleshoot issues efficiently, and optimize resource utilization.

Code example: Here’s how to create a simple timer metric:

public class MyService {

public void processRequest(String data) {
// ... processing logic

GraalVM Native Image Support:

What it means: Spring Boot 3.0 lets you create native images of your application using GraalVM. This translates your code into a platform-specific executable, delivering dramatic performance improvements:

Faster startup times: Native images launch significantly faster than traditional Java applications, reducing wait times for users.

Reduced memory footprint: Native images are typically smaller than their Java counterparts, leading to lower memory usage and improved scalability.

Improved performance: GraalVM optimizations can further enhance application performance, making your code run even faster.

Benefits: You’ll see lightning-fast startup times, lower memory consumption, and overall improved application performance.

Log4j2 Enhancements:

What it means: Spring Boot 3.0 integrates with enriched Log4j2 features, including:

Structured logging: Logs are now formatted with key-value pairs, making them easier to parse and analyze. No more cryptic log messages!

Configuration improvements: Simplified configuration management with YAML support and improved log file rotation.

Enhanced security: Log encryption and masking capabilities protect sensitive information.

Benefits: You gain clearer, more informative logs, easier log management, and enhanced security for your application.

Code example: Here’s how to configure structured logging with a layout:

public class LoggingConfig {

public StructuredLayout layout() {
return JsonLayout.newBuilder().build();

public Appender consoleAppender(StructuredLayout layout) {
ConsoleAppender appender = new ConsoleAppender();

Other Notable Features:

Spring Boot 3.0 doesn’t stop at the highlights mentioned above. Here are some additional noteworthy features:

Prometheus Support: Easier integration with Prometheus for comprehensive application monitoring.

Improved @ConstructorBinding Detection: Simplifies using constructor-based dependency injection, leading to cleaner and more concise code.

More Flexible Auto-configuration for Spring Data JDBC: Enhanced customization for database access, allowing you to tailor configurations to your specific needs.

Enabling Async Acks with Apache Kafka: Improved handling of asynchronous messages in Kafka streams, ensuring better reliability and data integrity.

Automatic Spring Initializer Integration: Streamlined application bootstrapping with Spring Initializr configurations automatically applied during project creation.

Improved Developer Experience: Enhancements to the Spring CLI tool, including faster project creation and debugging capabilities.

Beyond the Features:

Spring Boot 3.0 also brings several foundational changes aimed at improving maintainability and future-proofing:

Jakarta Servlet API as Default: The Jakarta Servlet API is the new standard for web development in Java, replacing the legacy Java Servlet API. This ensures your application is compatible with future advancements in the web development landscape.

Removal of Deprecated APIs: Spring Boot 3.0 has removed several deprecated APIs, encouraging developers to adopt modern and supported approaches. This promotes long-term code maintainability and avoids potential security vulnerabilities.

Enhanced Security: Spring Boot 3.0 emphasizes security best practices throughout the framework. Features like Spring Security by default and improved password hashing algorithms contribute to more secure applications.


Spring Boot 3.0 is a significant leap forward, offering a plethora of features and enhancements that empower developers to build high-performance, secure, and future-proof applications. By diving deeper into these features and embracing the foundational changes, you can unlock the full potential of Spring Boot and accelerate your Java development journey.

Additional Resources:

Spring Boot 3.0 Documentation: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/

Spring Initializr: https://start.spring.io/

Micrometer Documentation: https://micrometer.io/docs/

GraalVM Native Image: https://www.graalvm.org/22.0/reference-manual/native-image/

Remember, this is just a starting point. Continuously explore the official documentation, experiment with code examples, and engage with the Spring community to unlock the full potential of Spring Boot 3.0 and stay ahead of the curve in Java development.



Naveen Metta

I'm a Full Stack Developer with 2.5 years of experience. feel free to reach out for any help : mettanaveen701@gmail.com