Do not create persistent properties for Map and Collection-like entities.

These types are expected to behave like maps and collections and should not carry properties.
The only exception are types implementing Streamable as Streamable can be used in domain types.

Resolves: #3056
Original Pull Request: #3059

Author: mp911de

src/main/java/org/springframework/data/mapping/context/AbstractMappingContext.java

@@ -64,6 +64,7 @@
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.spel.EvaluationContextProvider;
 import org.springframework.data.spel.ExtensionAwareEvaluationContextProvider;
+import org.springframework.data.util.CustomCollections;
 import org.springframework.data.util.KotlinReflectionUtils;
 import org.springframework.data.util.NullableWrapperConverters;
 import org.springframework.data.util.Optionals;
@@ -458,16 +459,18 @@ private E doAddPersistentEntity(TypeInformation<?> typeInformation) {
 				persistentEntities.put(typeInformation, Optional.of(entity));
 			}
 
-			PropertyDescriptor[] pds = BeanUtils.getPropertyDescriptors(type);
-			Map<String, PropertyDescriptor> descriptors = new HashMap<>();
+			if (shouldCreateProperties(userTypeInformation)) {
+				PropertyDescriptor[] pds = BeanUtils.getPropertyDescriptors(type);
+				Map<String, PropertyDescriptor> descriptors = new HashMap<>();
 
-			for (PropertyDescriptor descriptor : pds) {
-				descriptors.put(descriptor.getName(), descriptor);
-			}
+				for (PropertyDescriptor descriptor : pds) {
+					descriptors.put(descriptor.getName(), descriptor);
+				}
 
-			PersistentPropertyCreator persistentPropertyCreator = new PersistentPropertyCreator(entity, descriptors);
-			ReflectionUtils.doWithFields(type, persistentPropertyCreator, PersistentPropertyFilter.INSTANCE);
-			persistentPropertyCreator.addPropertiesForRemainingDescriptors();
+				PersistentPropertyCreator persistentPropertyCreator = new PersistentPropertyCreator(entity, descriptors);
+				ReflectionUtils.doWithFields(type, persistentPropertyCreator, PersistentPropertyFilter.INSTANCE);
+				persistentPropertyCreator.addPropertiesForRemainingDescriptors();
+			}
 
 			entity.verify();
 
@@ -518,6 +521,35 @@ public Collection<TypeInformation<?>> getManagedTypes() {
 	 */
 	protected abstract P createPersistentProperty(Property property, E owner, SimpleTypeHolder simpleTypeHolder);
 
+	/**
+	 * Whether to create the {@link PersistentProperty}s for the given {@link TypeInformation}.
+	 *
+	 * @param typeInformation must not be {@literal null}.
+	 * @return {@literal true} properties should be created, {@literal false} otherwise
+	 */
+	protected boolean shouldCreateProperties(TypeInformation<?> typeInformation) {
+
+		Class<?> type = typeInformation.getType();
+
+		return !typeInformation.isMap() && !isCollectionLike(type);
+	}
+
+	/**
+	 * In contrast to TypeInformation, we do not consider types implementing Streamable collection-like as domain types
+	 * can implement that type.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @return
+	 * @see TypeInformation#isCollectionLike()
+	 */
+	private static boolean isCollectionLike(Class<?> type) {
+
+		return type.isArray() //
+				|| Iterable.class.equals(type) //
+				|| Streamable.class.equals(type) //
+				|| Collection.class.isAssignableFrom(type) || CustomCollections.isCollection(type);
+	}
+
 	@Override
 	public void afterPropertiesSet() {
 		initialize();
@@ -575,6 +607,7 @@ private PersistentPropertyCreator(E entity, Map<String, PropertyDescriptor> desc
 			this.remainingDescriptors = remainingDescriptors;
 		}
 
+		@Override
 		public void doWith(Field field) {
 
 			String fieldName = field.getName();

src/test/java/org/springframework/data/mapping/context/AbstractMappingContextUnitTests.java

@@ -22,14 +22,7 @@
 import groovy.lang.MetaClass;
 
 import java.time.LocalDateTime;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.TreeMap;
+import java.util.*;
 import java.util.function.Supplier;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -49,6 +42,7 @@
 import org.springframework.data.mapping.model.BasicPersistentEntity;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.util.StreamUtils;
+import org.springframework.data.util.Streamable;
 import org.springframework.data.util.TypeInformation;
 
 /**
@@ -285,6 +279,20 @@ void shouldNotCreatePersistentEntityForListButItsGenericTypeArgument() {
 				.doesNotContain(List.class, ArrayList.class);
 	}
 
+	@Test // GH-2390
+	void doesNotCreatePropertiesForMapAndCollectionTypes() {
+
+		assertThat(context.getPersistentEntity(HashSet.class)).isEmpty();
+		assertThat(context.getPersistentEntity(HashMap.class)).isEmpty();
+	}
+
+	@Test // GH-2390
+	void createsPropertiesForStreamableAndIterableTypes() {
+
+		assertThat(context.getPersistentEntity(MyStreamable.class)).hasSize(1);
+		assertThat(context.getPersistentEntity(MyIterable.class)).hasSize(1);
+	}
+
 	@Test // GH-2390
 	void detectsEntityTypeEvenIfSimpleTypeHolderConsidersCollectionsSimple() {
 
@@ -534,4 +542,28 @@ static abstract class Base$$SpringProxy$873fa2e extends Base implements SpringPr
 
 	}
 
+	static class MyIterable implements Iterable<StreamComponent> {
+
+		String name;
+
+		@Override
+		public Iterator<StreamComponent> iterator() {
+			return Collections.emptyIterator();
+		}
+	}
+
+	static class MyStreamable implements Streamable<StreamComponent> {
+
+		String name;
+
+		@Override
+		public Iterator<StreamComponent> iterator() {
+			return Collections.emptyIterator();
+		}
+	}
+
+	record StreamComponent(String name) {
+
+	}
+
 }