Add Qualified element on RootBeanDefinition

Improve RootBeanDefinition to specify an AnnotatedElement that holds
qualifier information. When such element is present, any qualifier that
it defines will be used to find a matching candidate.

Issue: SPR-14725

spring-beans/src/main/java/org/springframework/beans/factory/annotation/QualifierAnnotationAutowireCandidateResolver.java

@@ -17,6 +17,7 @@
 package org.springframework.beans.factory.annotation;
 
 import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
 import java.util.LinkedHashSet;
 import java.util.Map;
@@ -49,6 +50,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Mark Fisher
  * @author Juergen Hoeller
+ * @author Stephane Nicoll
  * @since 2.5
  * @see AutowireCandidateQualifier
  * @see Qualifier
@@ -225,8 +227,12 @@ public class QualifierAnnotationAutowireCandidateResolver extends GenericTypeAwa
 			qualifier = bd.getQualifier(ClassUtils.getShortName(type));
 		}
 		if (qualifier == null) {
-			// First, check annotation on factory method, if applicable
-			Annotation targetAnnotation = getFactoryMethodAnnotation(bd, type);
+			// First, check annotation on qualified element, if any
+			Annotation targetAnnotation = getQualifiedElementAnnotation(bd, type);
+			// Then, check annotation on factory method, if applicable
+			if (targetAnnotation == null) {
+				targetAnnotation = getFactoryMethodAnnotation(bd, type);
+			}
 			if (targetAnnotation == null) {
 				RootBeanDefinition dbd = getResolvedDecoratedDefinition(bd);
 				if (dbd != null) {
@@ -291,6 +297,11 @@ public class QualifierAnnotationAutowireCandidateResolver extends GenericTypeAwa
 		return true;
 	}
 
+	protected Annotation getQualifiedElementAnnotation(RootBeanDefinition bd, Class<? extends Annotation> type) {
+		AnnotatedElement qualifiedElement = bd.getQualifiedElement();
+		return (qualifiedElement != null ? AnnotationUtils.getAnnotation(qualifiedElement, type) : null);
+	}
+
 	protected Annotation getFactoryMethodAnnotation(RootBeanDefinition bd, Class<? extends Annotation> type) {
 		Method resolvedFactoryMethod = bd.getResolvedFactoryMethod();
 		return (resolvedFactoryMethod != null ? AnnotationUtils.getAnnotation(resolvedFactoryMethod, type) : null);

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

@@ -16,6 +16,7 @@
 
 package org.springframework.beans.factory.support;
 
+import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
@@ -58,6 +59,8 @@ public class RootBeanDefinition extends AbstractBeanDefinition {
 
 	boolean isFactoryMethodUnique = false;
 
+	volatile AnnotatedElement qualifiedElement;
+
 	/** Package-visible field for caching the determined Class of a given bean definition */
 	volatile Class<?> resolvedTargetType;
 
@@ -182,6 +185,7 @@ public class RootBeanDefinition extends AbstractBeanDefinition {
 		this.allowCaching = original.allowCaching;
 		this.targetType = original.targetType;
 		this.isFactoryMethodUnique = original.isFactoryMethodUnique;
+		this.qualifiedElement = original.qualifiedElement;
 	}
 
 	/**
@@ -257,6 +261,22 @@ public class RootBeanDefinition extends AbstractBeanDefinition {
 		this.isFactoryMethodUnique = true;
 	}
 
+	/**
+	 * Specify the {@link AnnotatedElement} defining qualifiers.
+	 * @since 4.3.3
+	 */
+	public void setQualifiedElement(AnnotatedElement qualifiedElement) {
+		this.qualifiedElement = qualifiedElement;
+	}
+
+	/**
+	 * Return the {@link AnnotatedElement} defining qualifiers, if any.
+	 * @since 4.3.3
+	 */
+	public AnnotatedElement getQualifiedElement() {
+		return this.qualifiedElement;
+	}
+
 	/**
 	 * Check whether the given candidate qualifies as a factory method.
 	 */