Merge branch '6.0.x'

# Conflicts:
#	spring-beans/src/main/java/org/springframework/beans/BeanUtils.java
#	spring-core/src/main/java/org/springframework/core/ResolvableType.java
#	spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.java

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java

@@ -1013,18 +1013,20 @@ public String toString() {
 	 */
 	protected abstract static class PropertyHandler {
 
+		@Nullable
 		private final Class<?> propertyType;
 
 		private final boolean readable;
 
 		private final boolean writable;
 
-		public PropertyHandler(Class<?> propertyType, boolean readable, boolean writable) {
+		public PropertyHandler(@Nullable Class<?> propertyType, boolean readable, boolean writable) {
 			this.propertyType = propertyType;
 			this.readable = readable;
 			this.writable = writable;
 		}
 
+		@Nullable
 		public Class<?> getPropertyType() {
 			return this.propertyType;
 		}

spring-beans/src/main/java/org/springframework/beans/BeanUtils.java

@@ -23,6 +23,7 @@
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.lang.reflect.Type;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
@@ -613,8 +614,8 @@ public static Class<?> findPropertyType(String propertyName, @Nullable Class<?>.
 	 * @return a corresponding MethodParameter object
 	 */
 	public static MethodParameter getWriteMethodParameter(PropertyDescriptor pd) {
-		if (pd instanceof GenericTypeAwarePropertyDescriptor typeAwarePd) {
-			return new MethodParameter(typeAwarePd.getWriteMethodParameter());
+		if (pd instanceof GenericTypeAwarePropertyDescriptor gpd) {
+			return new MethodParameter(gpd.getWriteMethodParameter());
 		}
 		else {
 			Method writeMethod = pd.getWriteMethod();
@@ -781,38 +782,28 @@ private static void copyProperties(Object source, Object target, @Nullable Class
 		if (editable != null) {
 			if (!editable.isInstance(target)) {
 				throw new IllegalArgumentException("Target class [" + target.getClass().getName() +
-						"] not assignable to Editable class [" + editable.getName() + "]");
+						"] not assignable to editable class [" + editable.getName() + "]");
 			}
 			actualEditable = editable;
 		}
 		PropertyDescriptor[] targetPds = getPropertyDescriptors(actualEditable);
 		Set<String> ignoredProps = (ignoreProperties != null ? new HashSet<>(Arrays.asList(ignoreProperties)) : null);
+		CachedIntrospectionResults sourceResults = (actualEditable != source.getClass() ?
+				CachedIntrospectionResults.forClass(source.getClass()) : null);
 
 		for (PropertyDescriptor targetPd : targetPds) {
 			Method writeMethod = targetPd.getWriteMethod();
 			if (writeMethod != null && (ignoredProps == null || !ignoredProps.contains(targetPd.getName()))) {
-				PropertyDescriptor sourcePd = getPropertyDescriptor(source.getClass(), targetPd.getName());
+				PropertyDescriptor sourcePd = (sourceResults != null ?
+						sourceResults.getPropertyDescriptor(targetPd.getName()) : targetPd);
 				if (sourcePd != null) {
 					Method readMethod = sourcePd.getReadMethod();
 					if (readMethod != null) {
-						ResolvableType sourceResolvableType = ResolvableType.forMethodReturnType(readMethod);
-						ResolvableType targetResolvableType = ResolvableType.forMethodParameter(writeMethod, 0);
-
-						// Ignore generic types in assignable check if either ResolvableType has unresolvable generics.
-						boolean isAssignable =
-								(sourceResolvableType.hasUnresolvableGenerics() || targetResolvableType.hasUnresolvableGenerics() ?
-										ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], readMethod.getReturnType()) :
-										targetResolvableType.isAssignableFrom(sourceResolvableType));
-
-						if (isAssignable) {
+						if (isAssignable(writeMethod, readMethod)) {
 							try {
-								if (!Modifier.isPublic(readMethod.getDeclaringClass().getModifiers())) {
-									readMethod.setAccessible(true);
-								}
+								ReflectionUtils.makeAccessible(readMethod);
 								Object value = readMethod.invoke(source);
-								if (!Modifier.isPublic(writeMethod.getDeclaringClass().getModifiers())) {
-									writeMethod.setAccessible(true);
-								}
+								ReflectionUtils.makeAccessible(writeMethod);
 								writeMethod.invoke(target, value);
 							}
 							catch (Throwable ex) {
@@ -826,6 +817,24 @@ private static void copyProperties(Object source, Object target, @Nullable Class
 		}
 	}
 
+	private static boolean isAssignable(Method writeMethod, Method readMethod) {
+		Type paramType = writeMethod.getGenericParameterTypes()[0];
+		if (paramType instanceof Class<?> clazz) {
+			return ClassUtils.isAssignable(clazz, readMethod.getReturnType());
+		}
+		else if (paramType.equals(readMethod.getGenericReturnType())) {
+			return true;
+		}
+		else {
+			ResolvableType sourceType = ResolvableType.forMethodReturnType(readMethod);
+			ResolvableType targetType = ResolvableType.forMethodParameter(writeMethod, 0);
+			// Ignore generic types in assignable check if either ResolvableType has unresolvable generics.
+			return (sourceType.hasUnresolvableGenerics() || targetType.hasUnresolvableGenerics() ?
+					ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], readMethod.getReturnType()) :
+					targetType.isAssignableFrom(sourceType));
+		}
+	}
+
 
 	/**
 	 * Inner class to avoid a hard dependency on Kotlin at runtime.
@@ -899,7 +908,6 @@ public static <T> T instantiateClass(Constructor<T> ctor, Object... args)
 			}
 			return kotlinConstructor.callBy(argParameters);
 		}
-
 	}
 
 }

spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java

@@ -144,7 +144,6 @@ public Object getValue() throws Exception {
 				ReflectionUtils.makeAccessible(this.field);
 				return this.field.get(getWrappedInstance());
 			}
-
 			catch (IllegalAccessException ex) {
 				throw new InvalidPropertyException(getWrappedClass(),
 						this.field.getName(), "Field is not accessible", ex);

spring-context/src/test/java/org/springframework/context/event/AbstractApplicationEventListenerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -36,6 +36,10 @@ protected ResolvableType getGenericApplicationEventType(String fieldName) {
 		}
 	}
 
+	protected <T> GenericTestEvent<T> createGenericTestEvent(T payload) {
+		return new GenericTestEvent<>(this, payload);
+	}
+
 
 	protected static class GenericTestEvent<T> extends ApplicationEvent {
 
@@ -51,6 +55,7 @@ public T getPayload() {
 		}
 	}
 
+
 	protected static class SmartGenericTestEvent<T> extends GenericTestEvent<T> implements ResolvableTypeProvider {
 
 		private final ResolvableType resolvableType;
@@ -67,52 +72,55 @@ public ResolvableType getResolvableType() {
 		}
 	}
 
+
 	protected static class StringEvent extends GenericTestEvent<String> {
 
 		public StringEvent(Object source, String payload) {
 			super(source, payload);
 		}
 	}
 
+
 	protected static class LongEvent extends GenericTestEvent<Long> {
 
 		public LongEvent(Object source, Long payload) {
 			super(source, payload);
 		}
 	}
 
-	protected <T> GenericTestEvent<T> createGenericTestEvent(T payload) {
-		return new GenericTestEvent<>(this, payload);
-	}
-
 
 	static class GenericEventListener implements ApplicationListener<GenericTestEvent<?>> {
+
 		@Override
 		public void onApplicationEvent(GenericTestEvent<?> event) {
 		}
 	}
 
+
 	static class ObjectEventListener implements ApplicationListener<GenericTestEvent<Object>> {
+
 		@Override
 		public void onApplicationEvent(GenericTestEvent<Object> event) {
 		}
 	}
 
-	static class UpperBoundEventListener
-			implements ApplicationListener<GenericTestEvent<? extends RuntimeException>> {
+
+	static class UpperBoundEventListener implements ApplicationListener<GenericTestEvent<? extends RuntimeException>> {
 
 		@Override
 		public void onApplicationEvent(GenericTestEvent<? extends RuntimeException> event) {
 		}
 	}
 
+
 	static class StringEventListener implements ApplicationListener<GenericTestEvent<String>> {
 
 		@Override
 		public void onApplicationEvent(GenericTestEvent<String> event) {
 		}
 	}
 
+
 	@SuppressWarnings("rawtypes")
 	static class RawApplicationListener implements ApplicationListener {
 
@@ -121,10 +129,10 @@ public void onApplicationEvent(ApplicationEvent event) {
 		}
 	}
 
+
 	static class TestEvents {
 
 		public GenericTestEvent<?> wildcardEvent;
-
 	}
 
 }

spring-context/src/test/java/org/springframework/context/event/GenericApplicationListenerAdapterTests.java

@@ -104,7 +104,8 @@ public void genericListenerStrictTypeNotMatchTypeErasure() {
 
 	@Test
 	public void genericListenerStrictTypeSubClass() {
-		supportsEventType(false, ObjectEventListener.class, ResolvableType.forClassWithGenerics(GenericTestEvent.class, Long.class));
+		supportsEventType(false, ObjectEventListener.class,
+				ResolvableType.forClassWithGenerics(GenericTestEvent.class, Long.class));
 	}
 
 	@Test

spring-core/src/main/java/org/springframework/core/ResolvableType.java

@@ -714,12 +714,12 @@ public ResolvableType getGeneric(@Nullable int... indexes) {
 	}
 
 	/**
-	 * Return an array of {@link ResolvableType ResolvableTypes} representing the generic parameters of
+	 * Return an array of {@code ResolvableType ResolvableTypes} representing the generic parameters of
 	 * this type. If no generics are available an empty array is returned. If you need to
 	 * access a specific generic consider using the {@link #getGeneric(int...)} method as
 	 * it allows access to nested generics and protects against
 	 * {@code IndexOutOfBoundsExceptions}.
-	 * @return an array of {@link ResolvableType ResolvableTypes} representing the generic parameters
+	 * @return an array of {@code ResolvableType ResolvableTypes} representing the generic parameters
 	 * (never {@code null})
 	 * @see #hasGenerics()
 	 * @see #getGeneric(int...)

spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.java

@@ -360,7 +360,7 @@ void getComponentTypeForClassArray() throws Exception {
 		ResolvableType type = ResolvableType.forField(field);
 		assertThat(type.isArray()).isTrue();
 		assertThat(type.getComponentType().getType())
-			.isEqualTo(((Class) field.getGenericType()).componentType());
+				.isEqualTo(((Class) field.getGenericType()).componentType());
 	}
 
 	@Test