Consistent type variable resolution for arrays/collections (in particular at field level)

Deprecating GenericCollectionTypeResolver in favor of direct ResolvableType usage.

Issue: SPR-15160
(cherry picked from commit 5e946c2)

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,7 +28,6 @@
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.InjectionPoint;
 import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
-import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterNameDiscoverer;
@@ -63,6 +62,8 @@ public class DependencyDescriptor extends InjectionPoint implements Serializable
 
 	private Class<?> containingClass;
 
+	private volatile ResolvableType resolvableType;
+
 
 	/**
 	 * Create a new descriptor for a method or constructor parameter.
@@ -214,6 +215,7 @@ public Object resolveCandidate(String beanName, Class<?> requiredType, BeanFacto
 	 */
 	public void increaseNestingLevel() {
 		this.nestingLevel++;
+		this.resolvableType = null;
 		if (this.methodParameter != null) {
 			this.methodParameter.increaseNestingLevel();
 		}
@@ -227,6 +229,7 @@ public void increaseNestingLevel() {
 	 */
 	public void setContainingClass(Class<?> containingClass) {
 		this.containingClass = containingClass;
+		this.resolvableType = null;
 		if (this.methodParameter != null) {
 			GenericTypeResolver.resolveParameterType(this.methodParameter, containingClass);
 		}
@@ -237,8 +240,12 @@ public void setContainingClass(Class<?> containingClass) {
 	 * @since 4.0
 	 */
 	public ResolvableType getResolvableType() {
-		return (this.field != null ? ResolvableType.forField(this.field, this.nestingLevel, this.containingClass) :
-				ResolvableType.forMethodParameter(this.methodParameter));
+		if (this.resolvableType == null) {
+			this.resolvableType = (this.field != null ?
+					ResolvableType.forField(this.field, this.nestingLevel, this.containingClass) :
+					ResolvableType.forMethodParameter(this.methodParameter));
+		}
+		return this.resolvableType;
 	}
 
 	/**
@@ -324,31 +331,37 @@ else if (type instanceof ParameterizedType) {
 	/**
 	 * Determine the generic element type of the wrapped Collection parameter/field, if any.
 	 * @return the generic type, or {@code null} if none
+	 * @deprecated as of 4.3.6, in favor of direct {@link ResolvableType} usage
 	 */
+	@Deprecated
 	public Class<?> getCollectionType() {
 		return (this.field != null ?
-				GenericCollectionTypeResolver.getCollectionFieldType(this.field, this.nestingLevel) :
-				GenericCollectionTypeResolver.getCollectionParameterType(this.methodParameter));
+				org.springframework.core.GenericCollectionTypeResolver.getCollectionFieldType(this.field, this.nestingLevel) :
+				org.springframework.core.GenericCollectionTypeResolver.getCollectionParameterType(this.methodParameter));
 	}
 
 	/**
 	 * Determine the generic key type of the wrapped Map parameter/field, if any.
 	 * @return the generic type, or {@code null} if none
+	 * @deprecated as of 4.3.6, in favor of direct {@link ResolvableType} usage
 	 */
+	@Deprecated
 	public Class<?> getMapKeyType() {
 		return (this.field != null ?
-				GenericCollectionTypeResolver.getMapKeyFieldType(this.field, this.nestingLevel) :
-				GenericCollectionTypeResolver.getMapKeyParameterType(this.methodParameter));
+				org.springframework.core.GenericCollectionTypeResolver.getMapKeyFieldType(this.field, this.nestingLevel) :
+				org.springframework.core.GenericCollectionTypeResolver.getMapKeyParameterType(this.methodParameter));
 	}
 
 	/**
 	 * Determine the generic value type of the wrapped Map parameter/field, if any.
 	 * @return the generic type, or {@code null} if none
+	 * @deprecated as of 4.3.6, in favor of direct {@link ResolvableType} usage
 	 */
+	@Deprecated
 	public Class<?> getMapValueType() {
 		return (this.field != null ?
-				GenericCollectionTypeResolver.getMapValueFieldType(this.field, this.nestingLevel) :
-				GenericCollectionTypeResolver.getMapValueParameterType(this.methodParameter));
+				org.springframework.core.GenericCollectionTypeResolver.getMapValueFieldType(this.field, this.nestingLevel) :
+				org.springframework.core.GenericCollectionTypeResolver.getMapValueParameterType(this.methodParameter));
 	}
 
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.TypeConverter;
-import org.springframework.core.GenericCollectionTypeResolver;
+import org.springframework.core.ResolvableType;
 
 /**
  * Simple factory for shared List instances. Allows for central setup
@@ -86,7 +86,7 @@ protected List<Object> createInstance() {
 		}
 		Class<?> valueType = null;
 		if (this.targetListClass != null) {
-			valueType = GenericCollectionTypeResolver.getCollectionType(this.targetListClass);
+			valueType = ResolvableType.forClass(this.targetListClass).asCollection().resolveGeneric();
 		}
 		if (valueType != null) {
 			TypeConverter converter = getBeanTypeConverter();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.TypeConverter;
-import org.springframework.core.GenericCollectionTypeResolver;
+import org.springframework.core.ResolvableType;
 
 /**
  * Simple factory for shared Map instances. Allows for central setup
@@ -87,8 +87,9 @@ protected Map<Object, Object> createInstance() {
 		Class<?> keyType = null;
 		Class<?> valueType = null;
 		if (this.targetMapClass != null) {
-			keyType = GenericCollectionTypeResolver.getMapKeyType(this.targetMapClass);
-			valueType = GenericCollectionTypeResolver.getMapValueType(this.targetMapClass);
+			ResolvableType mapType = ResolvableType.forClass(this.targetMapClass).asMap();
+			keyType = mapType.resolveGeneric(0);
+			valueType = mapType.resolveGeneric(1);
 		}
 		if (keyType != null || valueType != null) {
 			TypeConverter converter = getBeanTypeConverter();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.TypeConverter;
-import org.springframework.core.GenericCollectionTypeResolver;
+import org.springframework.core.ResolvableType;
 
 /**
  * Simple factory for shared Set instances. Allows for central setup
@@ -86,7 +86,7 @@ protected Set<Object> createInstance() {
 		}
 		Class<?> valueType = null;
 		if (this.targetSetClass != null) {
-			valueType = GenericCollectionTypeResolver.getCollectionType(this.targetSetClass);
+			valueType = ResolvableType.forClass(this.targetSetClass).asCollection().resolveGeneric();
 		}
 		if (valueType != null) {
 			TypeConverter converter = getBeanTypeConverter();

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

@@ -1148,6 +1148,15 @@ private Object resolveMultipleBeans(DependencyDescriptor descriptor, String bean
 		Class<?> type = descriptor.getDependencyType();
 		if (type.isArray()) {
 			Class<?> componentType = type.getComponentType();
+			ResolvableType resolvableType = descriptor.getResolvableType();
+			Class<?> resolvedArrayType = resolvableType.resolve();
+			if (resolvedArrayType != null && resolvedArrayType != type) {
+				type = resolvedArrayType;
+				componentType = resolvableType.getComponentType().resolve();
+			}
+			if (componentType == null) {
+				return null;
+			}
 			Map<String, Object> matchingBeans = findAutowireCandidates(beanName, componentType,
 					new MultiElementDescriptor(descriptor));
 			if (matchingBeans.isEmpty()) {
@@ -1164,7 +1173,7 @@ private Object resolveMultipleBeans(DependencyDescriptor descriptor, String bean
 			return result;
 		}
 		else if (Collection.class.isAssignableFrom(type) && type.isInterface()) {
-			Class<?> elementType = descriptor.getCollectionType();
+			Class<?> elementType = descriptor.getResolvableType().asCollection().resolveGeneric();
 			if (elementType == null) {
 				return null;
 			}
@@ -1184,11 +1193,12 @@ else if (Collection.class.isAssignableFrom(type) && type.isInterface()) {
 			return result;
 		}
 		else if (Map.class == type) {
-			Class<?> keyType = descriptor.getMapKeyType();
+			ResolvableType mapType = descriptor.getResolvableType().asMap();
+			Class<?> keyType = mapType.resolveGeneric(0);
 			if (String.class != keyType) {
 				return null;
 			}
-			Class<?> valueType = descriptor.getMapValueType();
+			Class<?> valueType = mapType.resolveGeneric(1);
 			if (valueType == null) {
 				return null;
 			}