HHH-19626 Properly resolving generic parameter type in subclass

Author: cigaly

tooling/metamodel-generator/src/main/java/org/hibernate/processor/annotation/AnnotationMetaEntity.java

@@ -67,6 +67,7 @@
 import static java.beans.Introspector.decapitalize;
 import static java.lang.Boolean.FALSE;
 import static java.util.Collections.emptyList;
+import static java.util.Objects.requireNonNullElse;
 import static java.util.stream.Collectors.toList;
 import static javax.lang.model.util.ElementFilter.fieldsIn;
 import static javax.lang.model.util.ElementFilter.methodsIn;
@@ -100,6 +101,7 @@
 import static org.hibernate.processor.util.TypeUtils.implementsInterface;
 import static org.hibernate.processor.util.TypeUtils.primitiveClassMatchesKind;
 import static org.hibernate.processor.util.TypeUtils.propertyName;
+import static org.hibernate.processor.util.TypeUtils.resolveTypeMirror;
 
 /**
  * Class used to collect meta information about an annotated type (entity, embeddable or mapped superclass).
@@ -2526,7 +2528,15 @@ enum FieldType {
 				return null;
 			}
 
-			if ( checkParameterType( entityType, param, memberType( member ) ) ) {
+			final var memberType = memberType( member );
+			final var attributeType = requireNonNullElse(
+					resolveTypeMirror(
+							entityType,
+							member.getEnclosingElement(),
+							memberType.toString()
+					), memberType
+			);
+			if ( checkParameterType( entityType, param, attributeType ) ) {
 				return FieldType.MULTIVALUED;
 			}
 			else if ( containsAnnotation( param, PATTERN ) ) {

tooling/metamodel-generator/src/main/java/org/hibernate/processor/util/GenericTypeParameterResolver.java

@@ -0,0 +1,58 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.processor.util;
+
+import javax.lang.model.element.Element;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.TypeMirror;
+import java.util.HashMap;
+import java.util.Map;
+
+public class GenericTypeParameterResolver {
+
+	private final Map<Element, Map<String, TypeMirror>> typeParameterMap;
+
+	public GenericTypeParameterResolver(TypeElement element) {
+		typeParameterMap = new HashMap<>();
+		resolveTypeParameters( element, Map.of() );
+	}
+
+	public String resolveTypeName(Element el, String name) {
+		final var mirror = resolveTypeMirror( el, name );
+		return mirror == null ? name : mirror.toString();
+	}
+
+	public TypeMirror resolveTypeMirror(Element el, String name) {
+		return typeParameterMap.getOrDefault( el, Map.of() ).get( name );
+	}
+
+	public void resolveTypeParameters(TypeElement element, Map<String, TypeMirror> map) {
+		resolveElementTypeParameters( element.getSuperclass(), map );
+		element.getInterfaces().forEach( iface -> resolveElementTypeParameters( iface, map ) );
+	}
+
+	private void resolveElementTypeParameters(TypeMirror type, Map<String, TypeMirror> parametersMap) {
+		if ( type instanceof DeclaredType declaredType
+				&& declaredType.asElement() instanceof TypeElement typeElement ) {
+			final var generic = typeElement.getTypeParameters();
+			final var map = new HashMap<String, TypeMirror>();
+			var typeArguments = declaredType.getTypeArguments();
+			if ( !( typeArguments.isEmpty() || generic.size() == typeArguments.size() ) ) {
+				throw new IndexOutOfBoundsException(
+						"Type %s : %d vs %d".formatted( type, generic.size(), typeArguments.size() ) );
+			}
+			for ( var n = 0; n < generic.size(); ++n ) {
+				final var mirror = typeArguments.isEmpty()
+						? generic.get( 0 ).getBounds().get( 0 )
+						: typeArguments.get( n );
+				final var value = mirror.toString();
+				map.put( generic.get( n ).toString(), parametersMap.getOrDefault( value, mirror ) );
+			}
+			typeParameterMap.put( typeElement, map );
+			resolveTypeParameters( typeElement, map );
+		}
+	}
+}

tooling/metamodel-generator/src/main/java/org/hibernate/processor/util/TypeUtils.java

@@ -94,6 +94,8 @@ public final class TypeUtils {
 		PRIMITIVES.put( TypeKind.DOUBLE, "double" );
 	}
 
+	private static final Map<Element, GenericTypeParameterResolver> typeResolversMap = new HashMap<>();
+
 	private TypeUtils() {
 	}
 
@@ -779,4 +781,17 @@ public static boolean isPrimitive(String paramType) {
 
 	public static final Set<String> PRIMITIVE_TYPES =
 			Set.of("boolean", "char", "long", "int", "short", "byte", "double", "float");
+
+	private static GenericTypeParameterResolver getTypeParameterResolver(TypeElement typeElement) {
+		final GenericTypeParameterResolver typeParameterResolver = typeResolversMap.get( typeElement );
+		if ( typeParameterResolver != null ) {
+			return typeParameterResolver;
+		}
+		return new GenericTypeParameterResolver( typeElement );
+	}
+
+	public static TypeMirror resolveTypeMirror(TypeElement typeElement, Element element, String name) {
+		final var typeParameterResolver = getTypeParameterResolver( typeElement );
+		return typeParameterResolver.resolveTypeMirror( element, name );
+	}
 }