New postProcessProperties variant on InstantiationAwareBeanPostProcessor

Allows for skipping the now-deprecated postProcessPropertyValues callback with its expensive PropertyDescriptor retrieval requirement. RequiredAnnotationBeanPostProcessor (which is dependent on postProcessPropertyValues) and the @Required annotation itself are also deprecated now: in favor of constructor injection (or afterPropertiesSet).

Issue: SPR-16918

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

@@ -365,9 +365,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	}
 
 	@Override
-	public PropertyValues postProcessPropertyValues(
-			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeanCreationException {
-
+	public PropertyValues postProcessProperties(PropertyValues pvs, Object bean, String beanName) {
 		InjectionMetadata metadata = findAutowiringMetadata(beanName, bean.getClass(), pvs);
 		try {
 			metadata.inject(bean, beanName, pvs);
@@ -381,6 +379,14 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 		return pvs;
 	}
 
+	@Deprecated
+	@Override
+	public PropertyValues postProcessPropertyValues(
+			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) {
+
+		return postProcessProperties(pvs, bean, beanName);
+	}
+
 	/**
 	 * 'Native' processing method for direct calls with an arbitrary target instance,
 	 * resolving all of its fields and methods which are annotated with {@code @Autowired}.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,7 +31,10 @@ import java.lang.annotation.Target;
  * @author Rob Harrop
  * @since 2.0
  * @see RequiredAnnotationBeanPostProcessor
+ * @deprecated as of 5.1, in favor of using constructor injection for required settings
+ * (or a custom {@link org.springframework.beans.factory.InitializingBean} implementation)
  */
+@Deprecated
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.METHOD)
 public @interface Required {

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

@@ -25,7 +25,6 @@ import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.springframework.beans.BeansException;
 import org.springframework.beans.PropertyValues;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
@@ -72,7 +71,10 @@ import org.springframework.util.Assert;
  * @since 2.0
  * @see #setRequiredAnnotationType
  * @see Required
+ * @deprecated as of 5.1, in favor of using constructor injection for required settings
+ * (or a custom {@link org.springframework.beans.factory.InitializingBean} implementation)
  */
+@Deprecated
 public class RequiredAnnotationBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter
 		implements MergedBeanDefinitionPostProcessor, PriorityOrdered, BeanFactoryAware {
 
@@ -142,7 +144,7 @@ public class RequiredAnnotationBeanPostProcessor extends InstantiationAwareBeanP
 
 	@Override
 	public PropertyValues postProcessPropertyValues(
-			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException {
+			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) {
 
 		if (!this.validatedBeanNames.contains(beanName)) {
 			if (!shouldSkip(this.beanFactory, beanName)) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -55,7 +55,7 @@ public interface InstantiationAwareBeanPostProcessor extends BeanPostProcessor {
 	 * {@link #postProcessAfterInitialization} callback from the configured
 	 * {@link BeanPostProcessor BeanPostProcessors}.
 	 * <p>This callback will only be applied to bean definitions with a bean class.
-	 * In particular, it will not be applied to beans with a "factory-method".
+	 * In particular, it will not be applied to beans with a factory method.
 	 * <p>Post-processors may implement the extended
 	 * {@link SmartInstantiationAwareBeanPostProcessor} interface in order
 	 * to predict the type of the bean object that they are going to return here.
@@ -65,8 +65,8 @@ public interface InstantiationAwareBeanPostProcessor extends BeanPostProcessor {
 	 * @return the bean object to expose instead of a default instance of the target bean,
 	 * or {@code null} to proceed with default instantiation
 	 * @throws org.springframework.beans.BeansException in case of errors
+	 * @see #postProcessAfterInstantiation
 	 * @see org.springframework.beans.factory.support.AbstractBeanDefinition#hasBeanClass
-	 * @see org.springframework.beans.factory.support.AbstractBeanDefinition#getFactoryMethodName
 	 */
 	@Nullable
 	default Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
@@ -86,11 +86,37 @@ public interface InstantiationAwareBeanPostProcessor extends BeanPostProcessor {
 	 * Returning {@code false} will also prevent any subsequent InstantiationAwareBeanPostProcessor
 	 * instances being invoked on this bean instance.
 	 * @throws org.springframework.beans.BeansException in case of errors
+	 * @see #postProcessBeforeInstantiation
 	 */
 	default boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
 		return true;
 	}
 
+	/**
+	 * Post-process the given property values before the factory applies them
+	 * to the given bean, without any need for property descriptors.
+	 * <p>Implementations should return {@code null} (the default) if they provide a custom
+	 * {@link #postProcessPropertyValues} implementation, and {@code pvs} otherwise.
+	 * In a future version of this interface (with {@link #postProcessPropertyValues} removed),
+	 * the default implementation will return the given {@code pvs} as-is directly.
+	 * @param pvs the property values that the factory is about to apply (never {@code null})
+	 * @param bean the bean instance created, but whose properties have not yet been set
+	 * @param beanName the name of the bean
+	 * @return the actual property values to apply to the given bean (can be the passed-in
+	 * PropertyValues instance), or {@code null} which proceeds with the existing properties
+	 * but specifically continues with a call to {@link #postProcessPropertyValues}
+	 * (requiring initialized {@code PropertyDescriptor}s for the current bean class)
+	 * @throws org.springframework.beans.BeansException in case of errors
+	 * @since 5.1
+	 * @see #postProcessPropertyValues
+	 */
+	@Nullable
+	default PropertyValues postProcessProperties(PropertyValues pvs, Object bean, String beanName)
+			throws BeansException {
+
+		return null;
+	}
+
 	/**
 	 * Post-process the given property values before the factory applies them
 	 * to the given bean. Allows for checking whether all dependencies have been
@@ -104,12 +130,14 @@ public interface InstantiationAwareBeanPostProcessor extends BeanPostProcessor {
 	 * dependency types - which the factory handles specifically - already filtered out)
 	 * @param bean the bean instance created, but whose properties have not yet been set
 	 * @param beanName the name of the bean
-	 * @return the actual property values to apply to the given bean
-	 * (can be the passed-in PropertyValues instance), or {@code null}
-	 * to skip property population
+	 * @return the actual property values to apply to the given bean (can be the passed-in
+	 * PropertyValues instance), or {@code null} to skip property population
 	 * @throws org.springframework.beans.BeansException in case of errors
+	 * @see #postProcessProperties
 	 * @see org.springframework.beans.MutablePropertyValues
+	 * @deprecated as of 5.1, in favor of {@link #postProcessProperties(PropertyValues, Object, String)}
 	 */
+	@Deprecated
 	@Nullable
 	default PropertyValues postProcessPropertyValues(
 			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -42,7 +42,7 @@ public abstract class InstantiationAwareBeanPostProcessorAdapter implements Smar
 
 	@Override
 	@Nullable
-	public Class<?> predictBeanType(Class<?> beanClass, String beanName) {
+	public Class<?> predictBeanType(Class<?> beanClass, String beanName) throws BeansException {
 		return null;
 	}
 
@@ -68,6 +68,14 @@ public abstract class InstantiationAwareBeanPostProcessorAdapter implements Smar
 		return true;
 	}
 
+	@Override
+	public PropertyValues postProcessProperties(PropertyValues pvs, Object bean, String beanName)
+			throws BeansException {
+
+		return null;
+	}
+
+	@Deprecated
 	@Override
 	public PropertyValues postProcessPropertyValues(
 			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException {

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

@@ -1292,6 +1292,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * @param mbd the bean definition for the bean
 	 * @param bw the BeanWrapper with bean instance
 	 */
+	@SuppressWarnings("deprecation")  // for postProcessPropertyValues
 	protected void populateBean(String beanName, RootBeanDefinition mbd, @Nullable BeanWrapper bw) {
 		if (bw == null) {
 			if (mbd.hasPropertyValues()) {
@@ -1347,25 +1348,33 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 		boolean hasInstAwareBpps = hasInstantiationAwareBeanPostProcessors();
 		boolean needsDepCheck = (mbd.getDependencyCheck() != RootBeanDefinition.DEPENDENCY_CHECK_NONE);
 
-		if (hasInstAwareBpps || needsDepCheck) {
+		PropertyDescriptor[] filteredPds = null;
+		if (hasInstAwareBpps) {
 			if (pvs == null) {
 				pvs = mbd.getPropertyValues();
 			}
-			PropertyDescriptor[] filteredPds = filterPropertyDescriptorsForDependencyCheck(bw, mbd.allowCaching);
-			if (hasInstAwareBpps) {
-				for (BeanPostProcessor bp : getBeanPostProcessors()) {
-					if (bp instanceof InstantiationAwareBeanPostProcessor) {
-						InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;
-						pvs = ibp.postProcessPropertyValues(pvs, filteredPds, bw.getWrappedInstance(), beanName);
-						if (pvs == null) {
+			for (BeanPostProcessor bp : getBeanPostProcessors()) {
+				if (bp instanceof InstantiationAwareBeanPostProcessor) {
+					InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;
+					PropertyValues pvsToUse = ibp.postProcessProperties(pvs, bw.getWrappedInstance(), beanName);
+					if (pvsToUse == null) {
+						if (filteredPds == null) {
+							filteredPds = filterPropertyDescriptorsForDependencyCheck(bw, mbd.allowCaching);
+						}
+						pvsToUse = ibp.postProcessPropertyValues(pvs, filteredPds, bw.getWrappedInstance(), beanName);
+						if (pvsToUse == null) {
 							return;
 						}
 					}
+					pvs = pvsToUse;
 				}
 			}
-			if (needsDepCheck) {
-				checkDependencies(beanName, mbd, filteredPds, pvs);
+		}
+		if (needsDepCheck) {
+			if (filteredPds == null) {
+				filteredPds = filterPropertyDescriptorsForDependencyCheck(bw, mbd.allowCaching);
 			}
+			checkDependencies(beanName, mbd, filteredPds, pvs);
 		}
 
 		if (pvs != null) {
@@ -1543,12 +1552,12 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * @see #isExcludedFromDependencyCheck(java.beans.PropertyDescriptor)
 	 */
 	protected void checkDependencies(
-			String beanName, AbstractBeanDefinition mbd, PropertyDescriptor[] pds, PropertyValues pvs)
+			String beanName, AbstractBeanDefinition mbd, PropertyDescriptor[] pds, @Nullable PropertyValues pvs)
 			throws UnsatisfiedDependencyException {
 
 		int dependencyCheck = mbd.getDependencyCheck();
 		for (PropertyDescriptor pd : pds) {
-			if (pd.getWriteMethod() != null && !pvs.contains(pd.getName())) {
+			if (pd.getWriteMethod() != null && (pvs == null || !pvs.contains(pd.getName()))) {
 				boolean isSimple = BeanUtils.isSimpleProperty(pd.getPropertyType());
 				boolean unsatisfied = (dependencyCheck == RootBeanDefinition.DEPENDENCY_CHECK_ALL) ||
 						(isSimple && dependencyCheck == RootBeanDefinition.DEPENDENCY_CHECK_SIMPLE) ||