News: What’s new in Spring Boot 3.0

“Spring Boot 3.0 is like trading your trusty bicycle for a warp-drive spaceship—fasten your seatbelts!” 🛸✨

🚀 Key Upgrades in Spring Boot 3.0

• Java 17+ & Jakarta EE 9 Baseline
  Spring Boot 3.0 now requires Java 17 or higher and fully migrates from the javax.* namespace to jakarta.*. javaCopyEdit// Before (Spring Boot 2.x) import javax.persistence.Entity; // After (Spring Boot 3.0) import jakarta.persistence.Entity;
• GraalVM Native Image & AOT Compilation
  Compile your app into a native executable for lightning-fast startup and tiny memory footprint. Just add the starter: xmlCopyEdit<!-- pom.xml --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-native</artifactId> </dependency>
• Unified Observability with Micrometer Observation API
  Instrument once to emit metrics, traces, and logs via a single, cohesive API—no disparate libraries needed.
• Declarative HTTP Interfaces
  Define HTTP clients with pure Java interfaces—no external client library required: javaCopyEdit@HttpExchange public interface GitHubClient { @GetExchange("/repos/{owner}/{repo}") Repo getRepo(@PathVariable String owner, @PathVariable String repo); }
• Problem Detail Support (RFC 7807)
  Standardized error responses out-of-the-box—throw a ResponseStatusException or customize via @ExceptionHandler.
• Modern Dependency Upgrades
  Hibernate 6.1, Jackson 2.14, Spring Security 6, Jetty 11, Liquibase 4.17, Micrometer 1.10, and more—plus richer Log4j2 profile support and smarter @ConfigurationProperties constructor binding.

🔧 Try It Out

1. Migrate Your Imports
   Refactor any javax.* to jakarta.* and clean up deprecated APIs in Spring Boot 2.7 before upgrading.
2. Build a Native Image
   Add the spring-boot-starter-native dependency, follow the AOT plugin guide, and compare startup times.
3. Enable Observability
   Include spring-boot-starter-actuator, configure Micrometer, and explore the new Observation API in your code.