Add graalvm-reachability-metadata for minio-java

[dpalmmna]

To use minio in a graalvm native application the reachability metadata could be added to https://github.com/oracle/graalvm-reachability-metadata for all users to use in native mode for optimised applications in cloud microservices.

[balamurugana]

Feel free to send a PR

[rcomblen]

For those landing here and using Spring Boot, here is a quick solution (working with Spring Boot 3.3.3), that allows me to put and get objects. Didn't test further features.

Add this class (@Slf4j comes from Lombok):

@Slf4j
public class MinioRuntimeHintsRegistrar implements RuntimeHintsRegistrar {


    List<String> packagesToScan = List.of(
            "io.minio",
            "org.simpleframework.xml.core"
    );

    private final BindingReflectionHintsRegistrar bindingReflectionHintsRegistrar = new BindingReflectionHintsRegistrar();


    @Override
    public void registerHints(RuntimeHints hint, ClassLoader classLoader) {
        for (String packageName : packagesToScan) {
            registerPackage(hint, packageName);
        }
    }

    private void registerPackage(RuntimeHints hint, String packageName) {
        Reflections reflections = new Reflections(packageName, new SubTypesScanner(false));
        Set<Class<?>> allTypes = reflections.getSubTypesOf(Object.class);
        log.info("Found " + allTypes.size() + " classes for package " + packageName);
        allTypes.stream().map(it -> it.getName()).sorted().forEach(it -> log.info("Registering " + it));
        allTypes.forEach(type -> {
            // Reusing behavior of @RegisterReflectionForBinding annotation
            bindingReflectionHintsRegistrar.registerReflectionHints(hint.reflection(), type);
        });
        reflections.getSubTypesOf(Serializable.class).stream().filter(it -> it.getCanonicalName() != null).forEach(type -> hint.serialization().registerType(type));
    }
}

And register it on a configuration class using

@ImportRuntimeHints(MinioRuntimeHintsRegistrar.class)

You'll need this dependency on your classpath:

<dependency>
  <groupId>org.reflections</groupId>
  <artifactId>reflections</artifactId>
  <version>0.10.2</version>
</dependency>