Difference Between Spring Boot 3 and Spring Boot 2

Jashan
2 min read5 days ago

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Spring Boot has become one of the most popular frameworks for building Java-based applications, particularly for microservices. With the release of Spring Boot 3, significant enhancements were introduced, building on the solid foundation laid by Spring Boot 2. Let’s take a look at some key differences between the two versions:

1. Java Compatibility

  • Spring Boot 2: Supports Java 8 through Java 17.
  • Spring Boot 3: Requires Java 17 as the minimum supported version.

Why it matters:
Java 17 introduces significant performance improvements, security enhancements, and new language features, making Spring Boot 3 better optimized for modern Java applications. If you’re using Spring Boot 3, you’ll need to upgrade your application to at least Java 17.

2. Jakarta EE 9 Transition

  • Spring Boot 2: Based on the older javax namespace.
  • Spring Boot 3: Migrated to the Jakarta EE 9 namespace (e.g., javax.persistence becomes jakarta.persistence).

Why it matters:
This change is part of the larger transition from Java EE to Jakarta EE. If your application relies on Java EE APIs, you’ll need to update import statements and configurations to reflect the Jakarta namespace when moving to Spring Boot 3.

3. GraalVM Native Image Support

  • Spring Boot 2: Limited native image support through third-party plugins.
  • Spring Boot 3: First-class support for GraalVM native images.

Why it matters:
GraalVM enables compiling Java applications into native executables, which can significantly reduce startup times and memory usage. With Spring Boot 3, this feature is more streamlined, making it easier to build ultra-fast, lightweight microservices.

4. Observability Improvements

  • Spring Boot 2: Limited observability with some out-of-the-box metrics and tracing support.
  • Spring Boot 3: Enhanced Micrometer integration for metrics and observability, including better support for distributed tracing and more extensive monitoring features.

Why it matters:
Spring Boot 3 makes it easier to track performance, errors, and metrics across complex, distributed systems, providing more insights into application health and performance.

5. Security Enhancements

  • Spring Boot 2: Uses Spring Security 5.x.
  • Spring Boot 3: Integrates Spring Security 6, which comes with improved security features, including better OAuth 2.0 support and a more streamlined security configuration.

Conclusion

Spring Boot 3 introduces modern Java compatibility, better performance optimizations, and improved observability, making it a powerful upgrade over Spring Boot 2. However, migrating from Spring Boot 2 to 3 requires careful planning, especially with Jakarta EE namespace changes and the requirement for Java 17.

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