GraalVM Native Images

Spring Boot supports GraalVM native images via AOT processing: ./mvnw -Pnative native:compile (or spring-boot:build-image -Pnative) produces a native executable that starts in tens of milliseconds and uses less memory — great for serverless, CLIs and scale-to-zero. Trade-offs: long build times, a closed-world assumption (reflection, proxies and resources need hints), and sometimes lower peak throughput than the JIT.

// Register reflection hints for classes used dynamically
@Configuration
@ImportRuntimeHints(ReportHints.class)
class ReportConfig {}

class ReportHints implements RuntimeHintsRegistrar {
    @Override
    public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
        hints.reflection().registerType(ReportTemplate.class, MemberCategory.values());
        hints.resources().registerPattern("templates/reports/*.html");
    }
}

./mvnw -Pnative native:compile
./target/shop        # starts in ~0.1s

Common pitfalls

• Libraries relying on runtime reflection without hints.
• Not testing the native build in CI (nativeTest).
• Choosing native for long-running high-throughput services without measuring.

Key points

• AOT + GraalVM for fast startup
• Runtime hints for reflection/resources
• Measure throughput trade-offs

Further reading: Spring Boot: Native images