What's New in Spring Boot 3.4.0-M2: An Overview with Examples

 

What's New in Spring Boot 3.4.0-M2: An Overview with Examples

Spring Boot 3.4.0-M2 is a milestone release that brings several exciting updates and improvements to the framework. This release continues to enhance developer productivity and performance, introducing new features, optimizations, and refinements. Below, we'll explore some of the key changes in Spring Boot 3.4.0-M2, along with practical examples.

1. Native Image Support Enhancements

Spring Boot 3.4.0-M2 continues to improve its support for GraalVM native images. This release includes optimizations that reduce the native image size and improve startup time.

Example: Configuring a Native Image

To create a native image with Spring Boot 3.4.0-M2, ensure that your project includes the necessary GraalVM dependencies:

xml:

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>spring-native</artifactId>
    <version>0.12.1</version>
</dependency>

Then, you can build the native image using the following Maven command:

bash:

./mvnw spring-boot:build-image -Pnative

This will generate a lightweight, fast-starting native executable.

2. New @DataMongoTest Stereotype

Spring Boot 3.4.0-M2 introduces the @DataMongoTest annotation, which simplifies testing with MongoDB by providing configuration and autoconfiguration for embedded MongoDB.

Example: Using @DataMongoTest

Here's how you can use @DataMongoTest in your test cases:

java:

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
import org.springframework.data.mongodb.core.MongoTemplate;

@DataMongoTest
class MongoRepositoryTests {

    @Autowired
    private MongoTemplate mongoTemplate;

    @Test
    void testMongoRepository() {
        // Your test logic here
    }
}

This annotation automatically configures an embedded MongoDB instance, making it easier to write and run tests.

3. Enhanced Observability Support

Observability is a critical aspect of modern applications, and Spring Boot 3.4.0-M2 enhances this by providing improved integration with observability tools like OpenTelemetry.

Example: Setting Up OpenTelemetry

To integrate OpenTelemetry with Spring Boot 3.4.0-M2, add the following dependencies:

xml:

<dependency>
    <groupId>io.opentelemetry</groupId>
    <artifactId>opentelemetry-api</artifactId>
    <version>1.20.0</version>
</dependency>
<dependency>
    <groupId>io.opentelemetry</groupId>
    <artifactId>opentelemetry-sdk</artifactId>
    <version>1.20.0</version>
</dependency>

Then, configure tracing and metrics in your application:

java:

import io.opentelemetry.api.trace.Tracer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class TracingConfig {

    @Bean
    public Tracer tracer() {
        // Configure and return your tracer instance
        return OpenTelemetry.get().getTracer("example-tracer");
    }
}

This setup allows you to capture and export traces and metrics from your Spring Boot application.

4. Updates to Spring Boot CLI

The Spring Boot CLI has been updated with improved support for Kotlin DSL and the latest versions of Spring Framework dependencies.

Example: Running a Kotlin Script with Spring Boot CLI

With the latest CLI, you can easily run Kotlin scripts:

kotlin:

@RestController
class HelloController {

    @GetMapping("/")
    fun hello() = "Hello, Spring Boot 3.4.0-M2!"
}

fun main(args: Array<String>) {
    runApplication<HelloController>(*args)
}

Run this script using the CLI:

bash:

spring run hello.kts

The CLI will automatically detect and configure the necessary dependencies.

5. Security Improvements

Spring Boot 3.4.0-M2 includes various security enhancements, such as updated dependency versions and improved support for OAuth 2.1.

Example: Configuring OAuth 2.1

To use OAuth 2.1, add the following dependencies to your project:

xml:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>

Then, configure your OAuth 2.1 client:

yaml:

spring:
  security:
    oauth2:
      client:
        registration:
          my-client:
            client-id: your-client-id
            client-secret: your-client-secret
            scope: read,write
            authorization-grant-type: authorization_code
            redirect-uri: "{baseUrl}/login/oauth2/code/{registrationId}"

This configuration will allow your application to authenticate users via OAuth 2.1.

Conclusion

Spring Boot 3.4.0-M2 is a feature-rich release that continues to build on the strengths of the Spring ecosystem. With enhancements in native image support, testing, observability, security, and more, this milestone release offers developers the tools they need to build robust and performant applications.

By leveraging these new features, you can take full advantage of the latest advancements in the Spring framework, ensuring that your applications are both modern and maintainable.