I'm wondering how the order of arguments is determined of a SAM when using the Adapter annotation. Feels like a bug, but not sure.

[willemsst]

I've been fighting this morning with the use of the @Adapter annotation and using a Qualifiers.byTypeArguments(..) to lookup my generated Single Abstract Method (SAM) classes.

For some weird reason, the order of types in the generated types, is not the same as the one in my interface that is referenced by the @adapter annotation.

I've been trying to find the magic of the AOP code generation in the source code, but couldn't spot it yet, so, if anyone can clarify how the order is determined, I would like to look into it to understand what's going on. Because, it feels like a bug that the order is changed, but as this is already at version 2.1.0, I might just do something stupid as well.

[graemerocher]

The logic for this can be found here:

micronaut-core/inject-java/src/main/java/io/micronaut/annotation/processing/BeanDefinitionInjectProcessor.java

Line 1410 in 1c2f878

private void visitAdaptedMethod(ExecutableElement method, AnnotationMetadata methodAnnotationMetadata) {

You can debug it running these tests:

micronaut-core/inject-java/src/test/groovy/io/micronaut/aop/adapter/MethodAdapterSpec.groovy

Line 27 in 1c2f878

void "test method adapter produces additional bean"() {

[willemsst]

Thank you for the quick response.

I've been adding my own classes to the test suite, added a test with multiple arguments in the event listener interface and debugged it. It was quite a deep dive, haha. But I found and resolved the issue.

It's a bug.

micronaut-core/inject-java/src/main/java/io/micronaut/annotation/processing/BeanDefinitionInjectProcessor.java

Line 1474 in 1c2f878

Map<String, Object> genericTypes = new HashMap<>();

-> this should be something like a LinkedHashMap in my opinion so the order of arguments is respected.

Because, in the next block of code, the HashMap with arguments is used to generate the getTypeArguments() method on the generated proxy class.

micronaut-core/inject-java/src/main/java/io/micronaut/annotation/processing/BeanDefinitionInjectProcessor.java

Lines 1527 to 1535 in 1c2f878

	if (!genericTypes.isEmpty()) {
	Map<String, Map<String, Object>> typeData = Collections.singletonMap(
	modelUtils.resolveTypeReference(typeToImplement).toString(),
	genericTypes
	);
	aopProxyWriter.visitTypeArguments(
	typeData
	);
	}

[graemerocher]

Great diagnosis! Would you like to send a PR?

[willemsst]

done. (i hope I did it correct as it's my first ever)
build check failed on Kotlin/Http stuff 🤷‍♂️
license/ca signed with multiple attempts but it's still in pending 🤷‍♂️

I hope you can move on with it. I won't put more time into this.