Annotation attributes not available at runtime

[dsyer]

Spring has a bunch of use cases for annotations and quite a rich set of convenience classes for introspecting them. They don't seem to fail, much, at runtime in a native image, but they don't actually work either.

Example code:

public class Annotations {

	@Autowired(required = false)
	public void setConverters(List<Bar> converters) {
	}

	public static void main(String[] args) throws Exception {
		new Annotations().run();
	}

	private void run() throws Exception {
		Method method = getClass().getMethod("setConverters", List.class);
		Autowired ann = method.getAnnotation(Autowired.class);
		AnnotationAttributes attributes = AnnotatedElementUtils
				.getMergedAnnotationAttributes(method, Autowired.class);
		// Null in native image, {required=false} in normal JDK
		System.err.println(attributes);

		// Boom! Blows up in native image, {required=false} in normal JDK
		// System.err.println(AnnotationUtils.getAnnotationAttributes(ann, true));
	}
}

I have tried to isolate the failure to specific reflective access to the annotation, but haven't been successful. Once (only) I saw some logs from the call to AnnotatedElementUtils:

Jul 09, 2018 8:51:29 AM org.springframework.core.annotation.AnnotationUtils handleIntrospectionFailure
INFO: Failed to introspect annotations on public void Annotations.setConverters(java.util.List): java.lang.IllegalStateException: Could not obtain annotation attribute value for public abstract boolean org.springframework.beans.factory.annotation.Autowired.required()

The fact that I only saw this once suggests there is perhaps another issue lurking to do with log configuration (Spring uses commons-logging which defaults to java.util.logging if nothing else is available).

[cstancu]

Thank you for reporting! Do you have a repo that we can use to easily replicate this?

[dsyer]

The code above will compile and run with just spring-beans (and spring-core which is transitive) on the class path.

[dsyer]

FWIW I think this is a duplicate of #999.

[sbrannen]

I just verified that the following (modified version of the sample application) passes in the spring-core native image tests build against GraalVM 20.0.

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.Method;
import java.util.List;

import org.junit.jupiter.api.Test;

import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.core.annotation.AnnotationAttributes;
import org.springframework.core.annotation.AnnotationUtils;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.entry;

public class AnnotationsTests {

	@Test
	void test() throws Exception {
		Method method = getClass().getMethod("setConverters", List.class);
		AnnotationAttributes attributes = AnnotatedElementUtils.getMergedAnnotationAttributes(method, Autowired.class);
		assertThat(attributes).containsExactly(entry("required", false));

		Autowired ann = method.getAnnotation(Autowired.class);
		assertThat(AnnotationUtils.getAnnotationAttributes(ann, true)).containsExactly(entry("required", false));
	}

	@Autowired(required = false)
	public void setConverters(List<Bar> converters) {
	}


	@Retention(RetentionPolicy.RUNTIME)
	@interface Autowired {

		boolean required() default true;
	}

	static class Bar {
	}

}

Thus, feel free to close this issue.