Resolve ApplicationListener against BeanDefinition.getResolvableType()

This covers ApplicationListener generics in factory method return types in particular but also allows for programmatic setTargetType hints.

Closes gh-23178

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanDefinition.java

@@ -19,6 +19,7 @@ package org.springframework.beans.factory.config;
 import org.springframework.beans.BeanMetadataElement;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.core.AttributeAccessor;
+import org.springframework.core.ResolvableType;
 import org.springframework.lang.Nullable;
 
 /**
@@ -304,6 +305,17 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 
 	// Read-only attributes
 
+	/**
+	 * Return a resolvable type for this bean definition,
+	 * based on the bean class or other specific metadata.
+	 * <p>This is typically fully resolved on a runtime-merged bean definition
+	 * but not necessarily on a configuration-time definition instance.
+	 * @return the resolvable type (potentially {@link ResolvableType#NONE})
+	 * @since 5.2
+	 * @see ConfigurableBeanFactory#getMergedBeanDefinition
+	 */
+	ResolvableType getResolvableType();
+
 	/**
 	 * Return whether this a <b>Singleton</b>, with a single, shared instance
 	 * returned on all calls.

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanDefinition.java

@@ -29,6 +29,7 @@ import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConstructorArgumentValues;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.io.DescriptiveResource;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
@@ -458,6 +459,16 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 		return resolvedClass;
 	}
 
+	/**
+	 * Return a resolvable type for this bean definition.
+	 * <p>This implementation delegates to {@link #getBeanClass()}.
+	 * @since 5.2
+	 */
+	@Override
+	public ResolvableType getResolvableType() {
+		return (hasBeanClass() ? ResolvableType.forClass(getBeanClass()) : ResolvableType.NONE);
+	}
+
 	/**
 	 * Set the name of the target scope for the bean.
 	 * <p>The default is singleton status, although this is only applied once

spring-beans/src/main/java/org/springframework/beans/factory/support/RootBeanDefinition.java

@@ -331,14 +331,28 @@ public class RootBeanDefinition extends AbstractBeanDefinition {
 	/**
 	 * Return a {@link ResolvableType} for this bean definition,
 	 * either from runtime-cached type information or from configuration-time
-	 * {@link #setTargetType(ResolvableType)} or {@link #setBeanClass(Class)}.
+	 * {@link #setTargetType(ResolvableType)} or {@link #setBeanClass(Class)},
+	 * also considering resolved factory method definitions.
 	 * @since 5.1
-	 * @see #getTargetType()
-	 * @see #getBeanClass()
+	 * @see #setTargetType(ResolvableType)
+	 * @see #setBeanClass(Class)
+	 * @see #setResolvedFactoryMethod(Method)
 	 */
+	@Override
 	public ResolvableType getResolvableType() {
 		ResolvableType targetType = this.targetType;
-		return (targetType != null ? targetType : ResolvableType.forClass(getBeanClass()));
+		if (targetType != null) {
+			return targetType;
+		}
+		ResolvableType returnType = this.factoryMethodReturnType;
+		if (returnType != null) {
+			return returnType;
+		}
+		Method factoryMethod = this.factoryMethodToIntrospect;
+		if (factoryMethod != null) {
+			return ResolvableType.forMethodReturnType(factoryMethod);
+		}
+		return super.getResolvableType();
 	}
 
 	/**