Fix test

experiment with resolving reactive types in document

.mvn/wrapper/maven-wrapper.properties

@@ -1,2 +1,2 @@
-#Mon Jan 30 10:48:12 CET 2023
-distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.7/apache-maven-3.8.7-bin.zip
+#Fri Jun 03 09:32:40 CEST 2022
+distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.5/apache-maven-3.8.5-bin.zip

ci/pipeline.properties

@@ -1,16 +1,16 @@
 # Java versions
-java.main.tag=17.0.6_10-jdk-focal
+java.main.tag=17.0.5_8-jdk-focal
 
 # Docker container images - standard
 docker.java.main.image=harbor-repo.vmware.com/dockerhub-proxy-cache/library/eclipse-temurin:${java.main.tag}
 
 # Supported versions of MongoDB
-docker.mongodb.4.4.version=4.4.18
-docker.mongodb.5.0.version=5.0.14
-docker.mongodb.6.0.version=6.0.4
+docker.mongodb.4.4.version=4.4.17
+docker.mongodb.5.0.version=5.0.13
+docker.mongodb.6.0.version=6.0.2
 
 # Supported versions of Redis
-docker.redis.6.version=6.2.10
+docker.redis.6.version=6.2.6
 
 # Supported versions of Cassandra
 docker.cassandra.3.version=3.11.14

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>4.1.0-M1</version>
+	<version>4.1.x-MANUAL-ENCRYPTION-SNAPSHOT</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data MongoDB</name>
@@ -15,7 +15,7 @@
 	<parent>
 		<groupId>org.springframework.data.build</groupId>
 		<artifactId>spring-data-parent</artifactId>
-		<version>3.1.0-M1</version>
+		<version>3.1.0-SNAPSHOT</version>
 	</parent>
 
 	<modules>
@@ -26,8 +26,8 @@
 	<properties>
 		<project.type>multi</project.type>
 		<dist.id>spring-data-mongodb</dist.id>
-		<springdata.commons>3.1.0-M1</springdata.commons>
-		<mongo>4.9.0</mongo>
+		<springdata.commons>3.1.0-SNAPSHOT</springdata.commons>
+		<mongo>4.8.2</mongo>
 		<mongo.reactivestreams>${mongo}</mongo.reactivestreams>
 		<jmh.version>1.19</jmh.version>
 	</properties>
@@ -145,8 +145,8 @@
 
 	<repositories>
 		<repository>
-			<id>spring-libs-milestone</id>
-			<url>https://repo.spring.io/libs-milestone</url>
+			<id>spring-libs-snapshot</id>
+			<url>https://repo.spring.io/libs-snapshot</url>
 			<snapshots>
 				<enabled>true</enabled>
 			</snapshots>

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>4.1.0-M1</version>
+		<version>4.1.x-MANUAL-ENCRYPTION-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb-distribution/pom.xml

@@ -15,7 +15,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>4.1.0-M1</version>
+		<version>4.1.x-MANUAL-ENCRYPTION-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb/pom.xml

@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>4.1.0-M1</version>
+		<version>4.1.x-MANUAL-ENCRYPTION-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 
@@ -112,6 +112,13 @@
 			<optional>true</optional>
 		</dependency>
 
+		<dependency>
+			<groupId>org.mongodb</groupId>
+			<artifactId>mongodb-crypt</artifactId>
+			<version>1.6.1</version>
+			<optional>true</optional>
+		</dependency>
+
 		<dependency>
 			<groupId>io.projectreactor</groupId>
 			<artifactId>reactor-core</artifactId>

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/CollectionPreparer.java

@@ -1,61 +0,0 @@
-/*
- * Copyright 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.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.core;
-
-import org.springframework.util.Assert;
-
-import com.mongodb.client.MongoCollection;
-
-/**
- * Interface for functional preparation of a {@link MongoCollection}.
- *
- * @author Mark Paluch
- * @since 4.1
- */
-public interface CollectionPreparer<T> {
-
-	/**
-	 * Returns a preparer that always returns its input collection.
-	 *
-	 * @return a preparer that always returns its input collection.
-	 */
-	static <T> CollectionPreparer<T> identity() {
-		return it -> it;
-	}
-
-	/**
-	 * Prepare the {@code collection}.
-	 *
-	 * @param collection the collection to prepare.
-	 * @return the prepared collection.
-	 */
-	T prepare(T collection);
-
-	/**
-	 * Returns a composed {@code CollectionPreparer} that first applies this preparer to the collection, and then applies
-	 * the {@code after} preparer to the result. If evaluation of either function throws an exception, it is relayed to
-	 * the caller of the composed function.
-	 *
-	 * @param after the collection preparer to apply after this function is applied.
-	 * @return a composed {@code CollectionPreparer} that first applies this preparer and then applies the {@code after}
-	 *         preparer.
-	 */
-	default CollectionPreparer<T> andThen(CollectionPreparer<T> after) {
-		Assert.notNull(after, "After CollectionPreparer must not be null");
-		return c -> after.prepare(prepare(c));
-	}
-
-}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/CollectionPreparerSupport.java

@@ -1,182 +0,0 @@
-/*
- * Copyright 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.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.core;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-
-import org.bson.Document;
-
-import com.mongodb.ReadConcern;
-import com.mongodb.ReadPreference;
-import com.mongodb.client.MongoCollection;
-
-/**
- * Support class for delegate implementations to apply {@link ReadConcern} and {@link ReadPreference} settings upon
- * {@link CollectionPreparer preparing a collection}.
- *
- * @author Mark Paluch
- * @since 4.1
- */
-class CollectionPreparerSupport implements ReadConcernAware, ReadPreferenceAware {
-
-	private final List<Object> sources;
-
-	private CollectionPreparerSupport(List<Object> sources) {
-		this.sources = sources;
-	}
-
-	<T> T doPrepare(T collection, Function<T, ReadConcern> concernAccessor, BiFunction<T, ReadConcern, T> concernFunction,
-			Function<T, ReadPreference> preferenceAccessor, BiFunction<T, ReadPreference, T> preferenceFunction) {
-
-		T collectionToUse = collection;
-
-		for (Object source : sources) {
-			if (source instanceof ReadConcernAware rca && rca.hasReadConcern()) {
-
-				ReadConcern concern = rca.getReadConcern();
-				if (concernAccessor.apply(collectionToUse) != concern) {
-					collectionToUse = concernFunction.apply(collectionToUse, concern);
-				}
-				break;
-			}
-		}
-
-		for (Object source : sources) {
-			if (source instanceof ReadPreferenceAware rpa && rpa.hasReadPreference()) {
-
-				ReadPreference preference = rpa.getReadPreference();
-				if (preferenceAccessor.apply(collectionToUse) != preference) {
-					collectionToUse = preferenceFunction.apply(collectionToUse, preference);
-				}
-				break;
-			}
-		}
-
-		return collectionToUse;
-	}
-
-	@Override
-	public boolean hasReadConcern() {
-
-		for (Object aware : sources) {
-			if (aware instanceof ReadConcernAware rca && rca.hasReadConcern()) {
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	@Override
-	public ReadConcern getReadConcern() {
-
-		for (Object aware : sources) {
-			if (aware instanceof ReadConcernAware rca && rca.hasReadConcern()) {
-				return rca.getReadConcern();
-			}
-		}
-
-		return null;
-	}
-
-	@Override
-	public boolean hasReadPreference() {
-
-		for (Object aware : sources) {
-			if (aware instanceof ReadPreferenceAware rpa && rpa.hasReadPreference()) {
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	@Override
-	public ReadPreference getReadPreference() {
-
-		for (Object aware : sources) {
-			if (aware instanceof ReadPreferenceAware rpa && rpa.hasReadPreference()) {
-				return rpa.getReadPreference();
-			}
-		}
-
-		return null;
-	}
-
-	static class CollectionPreparerDelegate extends CollectionPreparerSupport
-			implements CollectionPreparer<MongoCollection<Document>> {
-
-		private CollectionPreparerDelegate(List<Object> sources) {
-			super(sources);
-		}
-
-		public static CollectionPreparerDelegate of(ReadPreferenceAware... awares) {
-			return of((Object[]) awares);
-		}
-
-		public static CollectionPreparerDelegate of(Object... mixedAwares) {
-
-			if (mixedAwares.length == 1 && mixedAwares[0] instanceof CollectionPreparerDelegate) {
-				return (CollectionPreparerDelegate) mixedAwares[0];
-			}
-
-			return new CollectionPreparerDelegate(Arrays.asList(mixedAwares));
-		}
-
-		@Override
-		public MongoCollection<Document> prepare(MongoCollection<Document> collection) {
-			return doPrepare(collection, MongoCollection::getReadConcern, MongoCollection::withReadConcern,
-					MongoCollection::getReadPreference, MongoCollection::withReadPreference);
-		}
-
-	}
-
-	static class ReactiveCollectionPreparerDelegate extends CollectionPreparerSupport
-			implements CollectionPreparer<com.mongodb.reactivestreams.client.MongoCollection<Document>> {
-
-		private ReactiveCollectionPreparerDelegate(List<Object> sources) {
-			super(sources);
-		}
-
-		public static ReactiveCollectionPreparerDelegate of(ReadPreferenceAware... awares) {
-			return of((Object[]) awares);
-		}
-
-		public static ReactiveCollectionPreparerDelegate of(Object... mixedAwares) {
-
-			if (mixedAwares.length == 1 && mixedAwares[0] instanceof CollectionPreparerDelegate) {
-				return (ReactiveCollectionPreparerDelegate) mixedAwares[0];
-			}
-
-			return new ReactiveCollectionPreparerDelegate(Arrays.asList(mixedAwares));
-		}
-
-		@Override
-		public com.mongodb.reactivestreams.client.MongoCollection<Document> prepare(
-				com.mongodb.reactivestreams.client.MongoCollection<Document> collection) {
-			return doPrepare(collection, //
-					com.mongodb.reactivestreams.client.MongoCollection::getReadConcern,
-					com.mongodb.reactivestreams.client.MongoCollection::withReadConcern,
-					com.mongodb.reactivestreams.client.MongoCollection::getReadPreference,
-					com.mongodb.reactivestreams.client.MongoCollection::withReadPreference);
-		}
-
-	}
-
-}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ExecutableFindOperationSupport.java

@@ -20,6 +20,7 @@ import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.bson.Document;
+
 import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
@@ -167,8 +168,7 @@ class ExecutableFindOperationSupport implements ExecutableFindOperation {
 			Document queryObject = query.getQueryObject();
 			Document fieldsObject = query.getFieldsObject();
 
-			return template.doFind(template.createDelegate(query), getCollectionName(), queryObject, fieldsObject, domainType,
-					returnType,
+			return template.doFind(getCollectionName(), queryObject, fieldsObject, domainType, returnType,
 					getCursorPreparer(query, preparer));
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoExceptionTranslator.java

@@ -68,6 +68,8 @@ public class MongoExceptionTranslator implements PersistenceExceptionTranslator
 	private static final Set<String> DATA_INTEGRITY_EXCEPTIONS = new HashSet<>(
 			Arrays.asList("WriteConcernException", "MongoWriteException", "MongoBulkWriteException"));
 
+	private static final Set<String> SECURITY_EXCEPTIONS = Set.of("MongoCryptException");
+
 	@Nullable
 	public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
 
@@ -131,6 +133,8 @@ public class MongoExceptionTranslator implements PersistenceExceptionTranslator
 				return new ClientSessionException(ex.getMessage(), ex);
 			} else if (MongoDbErrorCodes.isTransactionFailureCode(code)) {
 				return new MongoTransactionException(ex.getMessage(), ex);
+			} else if(ex.getCause() != null && SECURITY_EXCEPTIONS.contains(ClassUtils.getShortName(ex.getCause().getClass()))) {
+				return new PermissionDeniedDataAccessException(ex.getMessage(), ex);
 			}
 
 			return new UncategorizedMongoDbException(ex.getMessage(), ex);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java

@@ -55,7 +55,6 @@ import org.springframework.data.mongodb.MongoDatabaseFactory;
 import org.springframework.data.mongodb.MongoDatabaseUtils;
 import org.springframework.data.mongodb.SessionSynchronization;
 import org.springframework.data.mongodb.core.BulkOperations.BulkMode;
-import org.springframework.data.mongodb.core.CollectionPreparerSupport.CollectionPreparerDelegate;
 import org.springframework.data.mongodb.core.DefaultBulkOperations.BulkOperationContext;
 import org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity;
 import org.springframework.data.mongodb.core.QueryOperations.AggregationDefinition;
@@ -67,7 +66,6 @@ import org.springframework.data.mongodb.core.QueryOperations.UpdateContext;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
-import org.springframework.data.mongodb.core.aggregation.AggregationOptions.Builder;
 import org.springframework.data.mongodb.core.aggregation.AggregationPipeline;
 import org.springframework.data.mongodb.core.aggregation.AggregationResults;
 import org.springframework.data.mongodb.core.aggregation.TypedAggregation;
@@ -85,6 +83,7 @@ import org.springframework.data.mongodb.core.mapreduce.MapReduceResults;
 import org.springframework.data.mongodb.core.query.BasicQuery;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Meta;
+import org.springframework.data.mongodb.core.query.Meta.CursorOption;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.UpdateDefinition;
@@ -113,23 +112,7 @@ import com.mongodb.client.result.DeleteResult;
 import com.mongodb.client.result.UpdateResult;
 
 /**
- * Primary implementation of {@link MongoOperations}. It simplifies the use of imperative MongoDB usage and helps to
- * avoid common errors. It executes core MongoDB workflow, leaving application code to provide {@link Document} and
- * extract results. This class executes BSON queries or updates, initiating iteration over {@link FindIterable} and
- * catching MongoDB exceptions and translating them to the generic, more informative exception hierarchy defined in the
- * org.springframework.dao package. Can be used within a service implementation via direct instantiation with a
- * {@link MongoDatabaseFactory} reference, or get prepared in an application context and given to services as bean
- * reference.
- * <p>
- * Note: The {@link MongoDatabaseFactory} should always be configured as a bean in the application context, in the first
- * case given to the service directly, in the second case to the prepared template.
- * <h3>{@link ReadPreference} and {@link com.mongodb.ReadConcern}</h3>
- * <p>
- * {@code ReadPreference} and {@code ReadConcern} are generally considered from {@link Query} and
- * {@link AggregationOptions} objects for the action to be executed on a particular {@link MongoCollection}.
- * <p>
- * You can also set the default {@link #setReadPreference(ReadPreference) ReadPreference} on the template level to
- * generally apply a {@link ReadPreference}.
+ * Primary implementation of {@link MongoOperations}.
  *
  * @author Thomas Risberg
  * @author Graeme Rocher
@@ -158,8 +141,7 @@ import com.mongodb.client.result.UpdateResult;
  * @author Bartłomiej Mazur
  * @author Michael Krog
  */
-public class MongoTemplate
-		implements MongoOperations, ApplicationContextAware, IndexOperationsProvider, ReadPreferenceAware {
+public class MongoTemplate implements MongoOperations, ApplicationContextAware, IndexOperationsProvider {
 
 	private static final Log LOGGER = LogFactory.getLog(MongoTemplate.class);
 	private static final WriteResultChecking DEFAULT_WRITE_RESULT_CHECKING = WriteResultChecking.NONE;
@@ -311,16 +293,6 @@ public class MongoTemplate
 		this.readPreference = readPreference;
 	}
 
-	@Override
-	public boolean hasReadPreference() {
-		return this.readPreference != null;
-	}
-
-	@Override
-	public ReadPreference getReadPreference() {
-		return this.readPreference;
-	}
-
 	/**
 	 * Configure whether lifecycle events such as {@link AfterLoadEvent}, {@link BeforeSaveEvent}, etc. should be
 	 * published or whether emission should be suppressed. Enabled by default.
@@ -391,10 +363,10 @@ public class MongoTemplate
 
 		if (enabled) {
 
-			this.countExecution = (collectionPreparer, collectionName, filter, options) -> {
+			this.countExecution = (collectionName, filter, options) -> {
 
 				if (!estimationFilter.test(filter, options)) {
-					return doExactCount(collectionPreparer, collectionName, filter, options);
+					return doExactCount(collectionName, filter, options);
 				}
 
 				EstimatedDocumentCountOptions estimatedDocumentCountOptions = new EstimatedDocumentCountOptions();
@@ -402,7 +374,7 @@ public class MongoTemplate
 					estimatedDocumentCountOptions.maxTime(options.getMaxTime(TimeUnit.MILLISECONDS), TimeUnit.MILLISECONDS);
 				}
 
-				return doEstimatedCount(collectionPreparer, collectionName, estimatedDocumentCountOptions);
+				return doEstimatedCount(collectionName, estimatedDocumentCountOptions);
 			};
 		} else {
 			this.countExecution = this::doExactCount;
@@ -471,9 +443,8 @@ public class MongoTemplate
 			Document mappedQuery = queryContext.getMappedQuery(persistentEntity);
 			Document mappedFields = queryContext.getMappedFields(persistentEntity, projection);
 
-			CollectionPreparerDelegate readPreference = createDelegate(query);
 			FindIterable<Document> cursor = new QueryCursorPreparer(query, entityType).initiateFind(collection,
-					col -> readPreference.prepare(col).find(mappedQuery, Document.class).projection(mappedFields));
+					col -> col.find(mappedQuery, Document.class).projection(mappedFields));
 
 			return new CloseableIterableCursorAdapter<>(cursor, exceptionTranslator,
 					new ProjectingReadCallback<>(mongoConverter, projection, collectionName)).stream();
@@ -546,7 +517,7 @@ public class MongoTemplate
 					serializeToJsonSafely(queryObject), sortObject, fieldsObject, collectionName));
 		}
 
-		this.executeQueryInternal(new FindCallback(createDelegate(query), queryObject, fieldsObject, null),
+		this.executeQueryInternal(new FindCallback(queryObject, fieldsObject, null),
 				preparer != null ? preparer : CursorPreparer.NO_OP_PREPARER, documentCallbackHandler, collectionName);
 	}
 
@@ -794,7 +765,7 @@ public class MongoTemplate
 
 		if (ObjectUtils.isEmpty(query.getSortObject())) {
 
-			return doFindOne(collectionName, createDelegate(query), query.getQueryObject(), query.getFieldsObject(),
+			return doFindOne(collectionName, query.getQueryObject(), query.getFieldsObject(),
 					new QueryCursorPreparer(query, entityClass), entityClass);
 		} else {
 			query.limit(1);
@@ -826,7 +797,7 @@ public class MongoTemplate
 		Document mappedQuery = queryContext.getMappedQuery(entityClass, this::getPersistentEntity);
 
 		return execute(collectionName,
-				new ExistsCallback(createDelegate(query), mappedQuery, queryContext.getCollation(entityClass).orElse(null)));
+				new ExistsCallback(mappedQuery, queryContext.getCollation(entityClass).orElse(null)));
 	}
 
 	// Find methods that take a Query to express the query and that return a List of objects.
@@ -843,7 +814,7 @@ public class MongoTemplate
 		Assert.notNull(collectionName, "CollectionName must not be null");
 		Assert.notNull(entityClass, "EntityClass must not be null");
 
-		return doFind(collectionName, createDelegate(query), query.getQueryObject(), query.getFieldsObject(), entityClass,
+		return doFind(collectionName, query.getQueryObject(), query.getFieldsObject(), entityClass,
 				new QueryCursorPreparer(query, entityClass));
 	}
 
@@ -863,8 +834,7 @@ public class MongoTemplate
 
 		String idKey = operations.getIdPropertyName(entityClass);
 
-		return doFindOne(collectionName, CollectionPreparer.identity(), new Document(idKey, id), new Document(),
-				entityClass);
+		return doFindOne(collectionName, new Document(idKey, id), new Document(), entityClass);
 	}
 
 	@Override
@@ -897,7 +867,10 @@ public class MongoTemplate
 						serializeToJsonSafely(mappedQuery), field, collectionName));
 			}
 
-			collection = createDelegate(query).prepare(collection);
+			QueryCursorPreparer preparer = new QueryCursorPreparer(query, entityClass);
+			if (preparer.hasReadPreference()) {
+				collection = collection.withReadPreference(preparer.getReadPreference());
+			}
 
 			DistinctIterable<T> iterable = collection.distinct(mappedFieldName, mappedQuery, mongoDriverCompatibleType);
 			distinctQueryContext.applyCollation(entityClass, iterable::collation);
@@ -947,18 +920,8 @@ public class MongoTemplate
 		String collection = StringUtils.hasText(collectionName) ? collectionName : getCollectionName(domainType);
 		String distanceField = operations.nearQueryDistanceFieldName(domainType);
 
-		Builder optionsBuilder = AggregationOptions.builder().collation(near.getCollation());
-
-		if (near.hasReadPreference()) {
-			optionsBuilder.readPreference(near.getReadPreference());
-		}
-
-		if(near.hasReadConcern()) {
-			optionsBuilder.readConcern(near.getReadConcern());
-		}
-
 		Aggregation $geoNear = TypedAggregation.newAggregation(domainType, Aggregation.geoNear(near, distanceField))
-				.withOptions(optionsBuilder.build());
+				.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
 
 		AggregationResults<Document> results = aggregate($geoNear, collection, Document.class);
 		EntityProjection<T, ?> projection = operations.introspectProjection(returnType, domainType);
@@ -1023,7 +986,7 @@ public class MongoTemplate
 			operations.forType(entityClass).getCollation(query).ifPresent(optionsToUse::collation);
 		}
 
-		return doFindAndModify(createDelegate(query), collectionName, query.getQueryObject(), query.getFieldsObject(),
+		return doFindAndModify(collectionName, query.getQueryObject(), query.getFieldsObject(),
 				getMappedSortObject(query, entityClass), entityClass, update, optionsToUse);
 	}
 
@@ -1045,7 +1008,6 @@ public class MongoTemplate
 		QueryContext queryContext = queryOperations.createQueryContext(query);
 
 		EntityProjection<T, S> projection = operations.introspectProjection(resultType, entityType);
-		CollectionPreparerDelegate collectionPreparer = createDelegate(query);
 		Document mappedQuery = queryContext.getMappedQuery(entity);
 		Document mappedFields = queryContext.getMappedFields(entity, projection);
 		Document mappedSort = queryContext.getMappedSort(entity);
@@ -1056,7 +1018,7 @@ public class MongoTemplate
 		maybeEmitEvent(new BeforeSaveEvent<>(replacement, mappedReplacement, collectionName));
 		maybeCallBeforeSave(replacement, mappedReplacement, collectionName);
 
-		T saved = doFindAndReplace(collectionPreparer, collectionName, mappedQuery, mappedFields, mappedSort,
+		T saved = doFindAndReplace(collectionName, mappedQuery, mappedFields, mappedSort,
 				queryContext.getCollation(entityType).orElse(null), entityType, mappedReplacement, options, projection);
 
 		if (saved != null) {
@@ -1084,7 +1046,7 @@ public class MongoTemplate
 		Assert.notNull(entityClass, "EntityClass must not be null");
 		Assert.notNull(collectionName, "CollectionName must not be null");
 
-		return doFindAndRemove(createDelegate(query), collectionName, query.getQueryObject(), query.getFieldsObject(),
+		return doFindAndRemove(collectionName, query.getQueryObject(), query.getFieldsObject(),
 				getMappedSortObject(query, entityClass), operations.forType(entityClass).getCollation(query).orElse(null),
 				entityClass);
 	}
@@ -1116,19 +1078,17 @@ public class MongoTemplate
 		CountOptions options = countContext.getCountOptions(entityClass);
 		Document mappedQuery = countContext.getMappedQuery(entityClass, mappingContext::getPersistentEntity);
 
-		CollectionPreparerDelegate readPreference = createDelegate(query);
-		return doCount(readPreference, collectionName, mappedQuery, options);
+		return doCount(collectionName, mappedQuery, options);
 	}
 
-	protected long doCount(CollectionPreparer collectionPreparer, String collectionName, Document filter,
-			CountOptions options) {
+	protected long doCount(String collectionName, Document filter, CountOptions options) {
 
 		if (LOGGER.isDebugEnabled()) {
 			LOGGER
 					.debug(String.format("Executing count: %s in collection: %s", serializeToJsonSafely(filter), collectionName));
 		}
 
-		return countExecution.countDocuments(collectionPreparer, collectionName, filter, options);
+		return countExecution.countDocuments(collectionName, filter, options);
 	}
 
 	/*
@@ -1137,13 +1097,11 @@ public class MongoTemplate
 	 */
 	@Override
 	public long estimatedCount(String collectionName) {
-		return doEstimatedCount(CollectionPreparerDelegate.of(this), collectionName, new EstimatedDocumentCountOptions());
+		return doEstimatedCount(collectionName, new EstimatedDocumentCountOptions());
 	}
 
-	protected long doEstimatedCount(CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			String collectionName, EstimatedDocumentCountOptions options) {
-		return execute(collectionName,
-				collection -> collectionPreparer.prepare(collection).estimatedDocumentCount(options));
+	protected long doEstimatedCount(String collectionName, EstimatedDocumentCountOptions options) {
+		return execute(collectionName, collection -> collection.estimatedDocumentCount(options));
 	}
 
 	@Override
@@ -1154,13 +1112,12 @@ public class MongoTemplate
 		CountOptions options = countContext.getCountOptions(entityClass);
 		Document mappedQuery = countContext.getMappedQuery(entityClass, mappingContext::getPersistentEntity);
 
-		return doExactCount(createDelegate(query), collectionName, mappedQuery, options);
+		return doExactCount(collectionName, mappedQuery, options);
 	}
 
-	protected long doExactCount(CollectionPreparer<MongoCollection<Document>> collectionPreparer, String collectionName,
-			Document filter, CountOptions options) {
-		return execute(collectionName, collection -> collectionPreparer.prepare(collection)
-				.countDocuments(CountQuery.of(filter).toQueryDocument(), options));
+	protected long doExactCount(String collectionName, Document filter, CountOptions options) {
+		return execute(collectionName,
+				collection -> collection.countDocuments(CountQuery.of(filter).toQueryDocument(), options));
 	}
 
 	protected boolean countCanBeEstimated(Document filter, CountOptions options) {
@@ -1220,8 +1177,8 @@ public class MongoTemplate
 	 */
 	protected MongoCollection<Document> prepareCollection(MongoCollection<Document> collection) {
 
-		if (this.readPreference != null && this.readPreference != collection.getReadPreference()) {
-			return collection.withReadPreference(readPreference);
+		if (this.readPreference != null) {
+			collection = collection.withReadPreference(readPreference);
 		}
 
 		return collection;
@@ -1797,7 +1754,7 @@ public class MongoTemplate
 	@Override
 	public <T> List<T> findAll(Class<T> entityClass, String collectionName) {
 		return executeFindMultiInternal(
-				new FindCallback(CollectionPreparer.identity(), new Document(), new Document(),
+				new FindCallback(new Document(), new Document(),
 						operations.forType(entityClass).getCollation().map(Collation::toMongoCollation).orElse(null)),
 				CursorPreparer.NO_OP_PREPARER, new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName),
 				collectionName);
@@ -1855,9 +1812,7 @@ public class MongoTemplate
 
 		String mapFunc = replaceWithResourceIfNecessary(mapFunction);
 		String reduceFunc = replaceWithResourceIfNecessary(reduceFunction);
-		CollectionPreparerDelegate readPreference = createDelegate(query);
-		MongoCollection<Document> inputCollection = readPreference
-				.prepare(getAndPrepareCollection(doGetDatabase(), inputCollectionName));
+		MongoCollection<Document> inputCollection = getAndPrepareCollection(doGetDatabase(), inputCollectionName);
 
 		// MapReduceOp
 		MapReduceIterable<Document> mapReduce = inputCollection.mapReduce(mapFunc, reduceFunc, Document.class);
@@ -2022,9 +1977,6 @@ public class MongoTemplate
 		if (!CollectionUtils.isEmpty(result)) {
 
 			Query byIdInQuery = operations.getByIdInQuery(result);
-			if (query.hasReadPreference()) {
-				byIdInQuery.withReadPreference(query.getReadPreference());
-			}
 
 			remove(byIdInQuery, entityClass, collectionName);
 		}
@@ -2080,7 +2032,7 @@ public class MongoTemplate
 		return execute(collectionName, collection -> {
 
 			List<Document> rawResult = new ArrayList<>();
-			CollectionPreparerDelegate delegate = CollectionPreparerDelegate.of(options);
+
 			Class<?> domainType = aggregation instanceof TypedAggregation ? ((TypedAggregation<?>) aggregation).getInputType()
 					: null;
 
@@ -2088,7 +2040,7 @@ public class MongoTemplate
 					() -> operations.forType(domainType) //
 							.getCollation());
 
-			AggregateIterable<Document> aggregateIterable = delegate.prepare(collection).aggregate(pipeline, Document.class) //
+			AggregateIterable<Document> aggregateIterable = collection.aggregate(pipeline, Document.class) //
 					.collation(collation.map(Collation::toMongoCollation).orElse(null)) //
 					.allowDiskUse(options.isAllowDiskUse());
 
@@ -2151,9 +2103,7 @@ public class MongoTemplate
 
 		return execute(collectionName, (CollectionCallback<Stream<O>>) collection -> {
 
-			CollectionPreparerDelegate delegate = CollectionPreparerDelegate.of(options);
-
-			AggregateIterable<Document> cursor = delegate.prepare(collection).aggregate(pipeline, Document.class) //
+			AggregateIterable<Document> cursor = collection.aggregate(pipeline, Document.class) //
 					.allowDiskUse(options.isAllowDiskUse());
 
 			if (options.getCursorBatchSize() != null) {
@@ -2394,16 +2344,14 @@ public class MongoTemplate
 	 * The query document is specified as a standard {@link Document} and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
 	 * @param entityClass the parameterized type of the returned list.
 	 * @return the converted object or {@literal null} if none exists.
 	 */
 	@Nullable
-	protected <T> T doFindOne(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<T> entityClass) {
-		return doFindOne(collectionName, collectionPreparer, query, fields, CursorPreparer.NO_OP_PREPARER, entityClass);
+	protected <T> T doFindOne(String collectionName, Document query, Document fields, Class<T> entityClass) {
+		return doFindOne(collectionName, query, fields, CursorPreparer.NO_OP_PREPARER, entityClass);
 	}
 
 	/**
@@ -2411,18 +2359,17 @@ public class MongoTemplate
 	 * The query document is specified as a standard {@link Document} and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
-	 * @param preparer the preparer used to modify the cursor on execution.
 	 * @param entityClass the parameterized type of the returned list.
+	 * @param preparer the preparer used to modify the cursor on execution.
 	 * @return the converted object or {@literal null} if none exists.
 	 * @since 2.2
 	 */
 	@Nullable
 	@SuppressWarnings("ConstantConditions")
-	protected <T> T doFindOne(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, CursorPreparer preparer, Class<T> entityClass) {
+	protected <T> T doFindOne(String collectionName, Document query, Document fields, CursorPreparer preparer,
+			Class<T> entityClass) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
@@ -2435,7 +2382,7 @@ public class MongoTemplate
 					serializeToJsonSafely(query), mappedFields, entityClass, collectionName));
 		}
 
-		return executeFindOneInternal(new FindOneCallback(collectionPreparer, mappedQuery, mappedFields, preparer),
+		return executeFindOneInternal(new FindOneCallback(mappedQuery, mappedFields, preparer),
 				new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName), collectionName);
 	}
 
@@ -2444,15 +2391,13 @@ public class MongoTemplate
 	 * query document is specified as a standard Document and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record
 	 * @param fields the document that specifies the fields to be returned
 	 * @param entityClass the parameterized type of the returned list.
 	 * @return the List of converted objects.
 	 */
-	protected <T> List<T> doFind(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<T> entityClass) {
-		return doFind(collectionName, collectionPreparer, query, fields, entityClass, null,
+	protected <T> List<T> doFind(String collectionName, Document query, Document fields, Class<T> entityClass) {
+		return doFind(collectionName, query, fields, entityClass, null,
 				new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName));
 	}
 
@@ -2462,7 +2407,6 @@ public class MongoTemplate
 	 * specified as a standard Document and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
 	 * @param entityClass the parameterized type of the returned list.
@@ -2470,15 +2414,14 @@ public class MongoTemplate
 	 *          (apply limits, skips and so on).
 	 * @return the {@link List} of converted objects.
 	 */
-	protected <T> List<T> doFind(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<T> entityClass, CursorPreparer preparer) {
-		return doFind(collectionName, collectionPreparer, query, fields, entityClass, preparer,
+	protected <T> List<T> doFind(String collectionName, Document query, Document fields, Class<T> entityClass,
+			CursorPreparer preparer) {
+		return doFind(collectionName, query, fields, entityClass, preparer,
 				new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName));
 	}
 
-	protected <S, T> List<T> doFind(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields,
-			Class<S> entityClass, @Nullable CursorPreparer preparer, DocumentCallback<T> objectCallback) {
+	protected <S, T> List<T> doFind(String collectionName, Document query, Document fields, Class<S> entityClass,
+			@Nullable CursorPreparer preparer, DocumentCallback<T> objectCallback) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
@@ -2491,7 +2434,7 @@ public class MongoTemplate
 					serializeToJsonSafely(mappedQuery), mappedFields, entityClass, collectionName));
 		}
 
-		return executeFindMultiInternal(new FindCallback(collectionPreparer, mappedQuery, mappedFields, null),
+		return executeFindMultiInternal(new FindCallback(mappedQuery, mappedFields, null),
 				preparer != null ? preparer : CursorPreparer.NO_OP_PREPARER, objectCallback, collectionName);
 	}
 
@@ -2501,8 +2444,8 @@ public class MongoTemplate
 	 *
 	 * @since 2.0
 	 */
-	<S, T> List<T> doFind(CollectionPreparer<MongoCollection<Document>> collectionPreparer, String collectionName,
-			Document query, Document fields, Class<S> sourceClass, Class<T> targetClass, CursorPreparer preparer) {
+	<S, T> List<T> doFind(String collectionName, Document query, Document fields, Class<S> sourceClass,
+			Class<T> targetClass, CursorPreparer preparer) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(sourceClass);
 		EntityProjection<T, S> projection = operations.introspectProjection(targetClass, sourceClass);
@@ -2516,7 +2459,7 @@ public class MongoTemplate
 					serializeToJsonSafely(mappedQuery), mappedFields, sourceClass, collectionName));
 		}
 
-		return executeFindMultiInternal(new FindCallback(collectionPreparer, mappedQuery, mappedFields, null), preparer,
+		return executeFindMultiInternal(new FindCallback(mappedQuery, mappedFields, null), preparer,
 				new ProjectingReadCallback<>(mongoConverter, projection, collectionName), collectionName);
 	}
 
@@ -2590,8 +2533,8 @@ public class MongoTemplate
 	 * @return the List of converted objects.
 	 */
 	@SuppressWarnings("ConstantConditions")
-	protected <T> T doFindAndRemove(CollectionPreparer collectionPreparer, String collectionName, Document query,
-			Document fields, Document sort, @Nullable Collation collation, Class<T> entityClass) {
+	protected <T> T doFindAndRemove(String collectionName, Document query, Document fields, Document sort,
+			@Nullable Collation collation, Class<T> entityClass) {
 
 		EntityReader<? super T, Bson> readerToUse = this.mongoConverter;
 
@@ -2602,15 +2545,14 @@ public class MongoTemplate
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
-		return executeFindOneInternal(new FindAndRemoveCallback(collectionPreparer,
-				queryMapper.getMappedObject(query, entity), fields, sort, collation),
+		return executeFindOneInternal(
+				new FindAndRemoveCallback(queryMapper.getMappedObject(query, entity), fields, sort, collation),
 				new ReadDocumentCallback<>(readerToUse, entityClass, collectionName), collectionName);
 	}
 
 	@SuppressWarnings("ConstantConditions")
-	protected <T> T doFindAndModify(CollectionPreparer collectionPreparer, String collectionName, Document query,
-			Document fields, Document sort, Class<T> entityClass, UpdateDefinition update,
-			@Nullable FindAndModifyOptions options) {
+	protected <T> T doFindAndModify(String collectionName, Document query, Document fields, Document sort,
+			Class<T> entityClass, UpdateDefinition update, @Nullable FindAndModifyOptions options) {
 
 		EntityReader<? super T, Bson> readerToUse = this.mongoConverter;
 
@@ -2635,7 +2577,7 @@ public class MongoTemplate
 		}
 
 		return executeFindOneInternal(
-				new FindAndModifyCallback(collectionPreparer, mappedQuery, fields, sort, mappedUpdate,
+				new FindAndModifyCallback(mappedQuery, fields, sort, mappedUpdate,
 						update.getArrayFilters().stream().map(ArrayFilter::asDocument).collect(Collectors.toList()), options),
 				new ReadDocumentCallback<>(readerToUse, entityClass, collectionName), collectionName);
 	}
@@ -2656,18 +2598,14 @@ public class MongoTemplate
 	 *         {@literal false} and {@link FindAndReplaceOptions#isUpsert() upsert} is {@literal false}.
 	 */
 	@Nullable
-	protected <T> T doFindAndReplace(CollectionPreparer collectionPreparer, String collectionName, Document mappedQuery,
-			Document mappedFields, Document mappedSort, @Nullable com.mongodb.client.model.Collation collation,
-			Class<?> entityType, Document replacement, FindAndReplaceOptions options, Class<T> resultType) {
+	protected <T> T doFindAndReplace(String collectionName, Document mappedQuery, Document mappedFields,
+			Document mappedSort, @Nullable com.mongodb.client.model.Collation collation, Class<?> entityType,
+			Document replacement, FindAndReplaceOptions options, Class<T> resultType) {
 
 		EntityProjection<T, ?> projection = operations.introspectProjection(resultType, entityType);
 
-		return doFindAndReplace(collectionPreparer, collectionName, mappedQuery, mappedFields, mappedSort, collation,
-				entityType, replacement, options, projection);
-	}
-
-	CollectionPreparerDelegate createDelegate(Query query) {
-		return CollectionPreparerDelegate.of(query);
+		return doFindAndReplace(collectionName, mappedQuery, mappedFields, mappedSort, collation, entityType, replacement,
+				options, projection);
 	}
 
 	/**
@@ -2687,9 +2625,9 @@ public class MongoTemplate
 	 * @since 3.4
 	 */
 	@Nullable
-	private <T> T doFindAndReplace(CollectionPreparer collectionPreparer, String collectionName, Document mappedQuery,
-			Document mappedFields, Document mappedSort, @Nullable com.mongodb.client.model.Collation collation,
-			Class<?> entityType, Document replacement, FindAndReplaceOptions options, EntityProjection<T, ?> projection) {
+	private <T> T doFindAndReplace(String collectionName, Document mappedQuery, Document mappedFields,
+			Document mappedSort, @Nullable com.mongodb.client.model.Collation collation, Class<?> entityType,
+			Document replacement, FindAndReplaceOptions options, EntityProjection<T, ?> projection) {
 
 		if (LOGGER.isDebugEnabled()) {
 			LOGGER
@@ -2700,9 +2638,9 @@ public class MongoTemplate
 							serializeToJsonSafely(mappedSort), entityType, serializeToJsonSafely(replacement), collectionName));
 		}
 
-		return executeFindOneInternal(new FindAndReplaceCallback(collectionPreparer, mappedQuery, mappedFields, mappedSort,
-				replacement, collation, options), new ProjectingReadCallback<>(mongoConverter, projection, collectionName),
-				collectionName);
+		return executeFindOneInternal(
+				new FindAndReplaceCallback(mappedQuery, mappedFields, mappedSort, replacement, collation, options),
+				new ProjectingReadCallback<>(mongoConverter, projection, collectionName), collectionName);
 	}
 
 	/**
@@ -2872,15 +2810,12 @@ public class MongoTemplate
 	 */
 	private static class FindOneCallback implements CollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Optional<Document> fields;
 		private final CursorPreparer cursorPreparer;
 
-		FindOneCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields,
-				CursorPreparer preparer) {
+		FindOneCallback(Document query, Document fields, CursorPreparer preparer) {
 
-			this.collectionPreparer = collectionPreparer;
 			this.query = query;
 			this.fields = Optional.of(fields).filter(it -> !ObjectUtils.isEmpty(fields));
 			this.cursorPreparer = preparer;
@@ -2889,8 +2824,7 @@ public class MongoTemplate
 		@Override
 		public Document doInCollection(MongoCollection<Document> collection) throws MongoException, DataAccessException {
 
-			FindIterable<Document> iterable = cursorPreparer.initiateFind(collection,
-					col -> collectionPreparer.prepare(col).find(query, Document.class));
+			FindIterable<Document> iterable = cursorPreparer.initiateFind(collection, col -> col.find(query, Document.class));
 
 			if (LOGGER.isDebugEnabled()) {
 
@@ -2917,18 +2851,15 @@ public class MongoTemplate
 	 */
 	private static class FindCallback implements CollectionCallback<FindIterable<Document>> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final @Nullable com.mongodb.client.model.Collation collation;
 
-		public FindCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, @Nullable com.mongodb.client.model.Collation collation) {
+		public FindCallback(Document query, Document fields, @Nullable com.mongodb.client.model.Collation collation) {
 
 			Assert.notNull(query, "Query must not be null");
 			Assert.notNull(fields, "Fields must not be null");
 
-			this.collectionPreparer = collectionPreparer;
 			this.query = query;
 			this.fields = fields;
 			this.collation = collation;
@@ -2938,8 +2869,7 @@ public class MongoTemplate
 		public FindIterable<Document> doInCollection(MongoCollection<Document> collection)
 				throws MongoException, DataAccessException {
 
-			FindIterable<Document> findIterable = collectionPreparer.prepare(collection).find(query, Document.class)
-					.projection(fields);
+			FindIterable<Document> findIterable = collection.find(query, Document.class).projection(fields);
 
 			if (collation != null) {
 				findIterable = findIterable.collation(collation);
@@ -2957,14 +2887,11 @@ public class MongoTemplate
 	 */
 	private class ExistsCallback implements CollectionCallback<Boolean> {
 
-		private final CollectionPreparer collectionPreparer;
 		private final Document mappedQuery;
 		private final com.mongodb.client.model.Collation collation;
 
-		ExistsCallback(CollectionPreparer collectionPreparer, Document mappedQuery,
-				com.mongodb.client.model.Collation collation) {
+		ExistsCallback(Document mappedQuery, com.mongodb.client.model.Collation collation) {
 
-			this.collectionPreparer = collectionPreparer;
 			this.mappedQuery = mappedQuery;
 			this.collation = collation;
 		}
@@ -2972,7 +2899,7 @@ public class MongoTemplate
 		@Override
 		public Boolean doInCollection(MongoCollection<Document> collection) throws MongoException, DataAccessException {
 
-			return doCount(collectionPreparer, collection.getNamespace().getCollectionName(), mappedQuery,
+			return doCount(collection.getNamespace().getCollectionName(), mappedQuery,
 					new CountOptions().limit(1).collation(collation)) > 0;
 		}
 	}
@@ -2985,15 +2912,12 @@ public class MongoTemplate
 	 */
 	private static class FindAndRemoveCallback implements CollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
 		private final Optional<Collation> collation;
 
-		FindAndRemoveCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, @Nullable Collation collation) {
-			this.collectionPreparer = collectionPreparer;
+		FindAndRemoveCallback(Document query, Document fields, Document sort, @Nullable Collation collation) {
 
 			this.query = query;
 			this.fields = fields;
@@ -3007,13 +2931,12 @@ public class MongoTemplate
 			FindOneAndDeleteOptions opts = new FindOneAndDeleteOptions().sort(sort).projection(fields);
 			collation.map(Collation::toMongoCollation).ifPresent(opts::collation);
 
-			return collectionPreparer.prepare(collection).findOneAndDelete(query, opts);
+			return collection.findOneAndDelete(query, opts);
 		}
 	}
 
 	private static class FindAndModifyCallback implements CollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
@@ -3021,10 +2944,9 @@ public class MongoTemplate
 		private final List<Document> arrayFilters;
 		private final FindAndModifyOptions options;
 
-		FindAndModifyCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, Object update, List<Document> arrayFilters, FindAndModifyOptions options) {
+		FindAndModifyCallback(Document query, Document fields, Document sort, Object update, List<Document> arrayFilters,
+				FindAndModifyOptions options) {
 
-			this.collectionPreparer = collectionPreparer;
 			this.query = query;
 			this.fields = fields;
 			this.sort = sort;
@@ -3053,9 +2975,9 @@ public class MongoTemplate
 			}
 
 			if (update instanceof Document) {
-				return collectionPreparer.prepare(collection).findOneAndUpdate(query, (Document) update, opts);
+				return collection.findOneAndUpdate(query, (Document) update, opts);
 			} else if (update instanceof List) {
-				return collectionPreparer.prepare(collection).findOneAndUpdate(query, (List<Document>) update, opts);
+				return collection.findOneAndUpdate(query, (List<Document>) update, opts);
 			}
 
 			throw new IllegalArgumentException(String.format("Using %s is not supported in findOneAndUpdate", update));
@@ -3071,7 +2993,6 @@ public class MongoTemplate
 	 */
 	private static class FindAndReplaceCallback implements CollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
@@ -3079,10 +3000,9 @@ public class MongoTemplate
 		private final @Nullable com.mongodb.client.model.Collation collation;
 		private final FindAndReplaceOptions options;
 
-		FindAndReplaceCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, Document update, @Nullable com.mongodb.client.model.Collation collation,
-				FindAndReplaceOptions options) {
-			this.collectionPreparer = collectionPreparer;
+		FindAndReplaceCallback(Document query, Document fields, Document sort, Document update,
+				@Nullable com.mongodb.client.model.Collation collation, FindAndReplaceOptions options) {
+
 			this.query = query;
 			this.fields = fields;
 			this.sort = sort;
@@ -3107,7 +3027,7 @@ public class MongoTemplate
 				opts.returnDocument(ReturnDocument.AFTER);
 			}
 
-			return collectionPreparer.prepare(collection).findOneAndReplace(query, update, opts);
+			return collection.findOneAndReplace(query, update, opts);
 		}
 	}
 
@@ -3289,6 +3209,11 @@ public class MongoTemplate
 			return cursorToUse;
 		}
 
+		@Override
+		public ReadPreference getReadPreference() {
+			return query.getMeta().getFlags().contains(CursorOption.SECONDARY_READS) ? ReadPreference.primaryPreferred()
+					: null;
+		}
 	}
 
 	/**
@@ -3474,7 +3399,6 @@ public class MongoTemplate
 
 	@FunctionalInterface
 	interface CountExecution {
-		long countDocuments(CollectionPreparer collectionPreparer, String collection, Document filter,
-				CountOptions options);
+		long countDocuments(String collection, Document filter, CountOptions options);
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveFindOperationSupport.java

@@ -20,7 +20,6 @@ import reactor.core.publisher.Mono;
 
 import org.bson.Document;
 import org.springframework.dao.IncorrectResultSizeDataAccessException;
-import org.springframework.data.mongodb.core.CollectionPreparerSupport.ReactiveCollectionPreparerDelegate;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.SerializationUtils;
@@ -68,8 +67,8 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 		private final String collection;
 		private final Query query;
 
-		ReactiveFindSupport(ReactiveMongoTemplate template, Class<?> domainType, Class<T> returnType, String collection,
-				Query query) {
+		ReactiveFindSupport(ReactiveMongoTemplate template, Class<?> domainType, Class<T> returnType,
+				String collection, Query query) {
 
 			this.template = template;
 			this.domainType = domainType;
@@ -170,8 +169,8 @@ class ReactiveFindOperationSupport implements ReactiveFindOperation {
 			Document queryObject = query.getQueryObject();
 			Document fieldsObject = query.getFieldsObject();
 
-			return template.doFind(getCollectionName(), ReactiveCollectionPreparerDelegate.of(query), queryObject,
-					fieldsObject, domainType, returnType, preparer != null ? preparer : getCursorPreparer(query));
+			return template.doFind(getCollectionName(), queryObject, fieldsObject, domainType, returnType,
+					preparer != null ? preparer : getCursorPreparer(query));
 		}
 
 		@SuppressWarnings("unchecked")

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java

@@ -30,6 +30,7 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.function.BiFunction;
@@ -70,7 +71,6 @@ import org.springframework.data.mongodb.MongoDatabaseFactory;
 import org.springframework.data.mongodb.ReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.ReactiveMongoDatabaseUtils;
 import org.springframework.data.mongodb.SessionSynchronization;
-import org.springframework.data.mongodb.core.CollectionPreparerSupport.ReactiveCollectionPreparerDelegate;
 import org.springframework.data.mongodb.core.EntityOperations.AdaptibleEntity;
 import org.springframework.data.mongodb.core.QueryOperations.AggregationDefinition;
 import org.springframework.data.mongodb.core.QueryOperations.CountContext;
@@ -81,7 +81,6 @@ import org.springframework.data.mongodb.core.QueryOperations.UpdateContext;
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
-import org.springframework.data.mongodb.core.aggregation.AggregationOptions.Builder;
 import org.springframework.data.mongodb.core.aggregation.AggregationPipeline;
 import org.springframework.data.mongodb.core.aggregation.PrefixingDelegatingAggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.RelaxedTypeBasedAggregationOperationContext;
@@ -107,6 +106,7 @@ import org.springframework.data.mongodb.core.mapreduce.MapReduceOptions;
 import org.springframework.data.mongodb.core.query.BasicQuery;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Meta;
+import org.springframework.data.mongodb.core.query.Meta.CursorOption;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.UpdateDefinition;
@@ -148,18 +148,9 @@ import com.mongodb.reactivestreams.client.MongoDatabase;
  * extract results. This class executes BSON queries or updates, initiating iteration over {@link FindPublisher} and
  * catching MongoDB exceptions and translating them to the generic, more informative exception hierarchy defined in the
  * org.springframework.dao package. Can be used within a service implementation via direct instantiation with a
- * {@link ReactiveMongoDatabaseFactory} reference, or get prepared in an application context and given to services as
- * bean reference.
- * <p>
- * Note: The {@link ReactiveMongoDatabaseFactory} should always be configured as a bean in the application context, in
- * the first case given to the service directly, in the second case to the prepared template.
- * <h3>{@link ReadPreference} and {@link com.mongodb.ReadConcern}</h3>
- * <p>
- * {@code ReadPreference} and {@code ReadConcern} are generally considered from {@link Query} and
- * {@link AggregationOptions} objects for the action to be executed on a particular {@link MongoCollection}.
- * <p>
- * You can also set the default {@link #setReadPreference(ReadPreference) ReadPreference} on the template level to
- * generally apply a {@link ReadPreference}.
+ * {@link SimpleReactiveMongoDatabaseFactory} reference, or get prepared in an application context and given to services
+ * as bean reference. Note: The {@link SimpleReactiveMongoDatabaseFactory} should always be configured as a bean in the
+ * application context, in the first case given to the service directly, in the second case to the prepared template.
  *
  * @author Mark Paluch
  * @author Christoph Strobl
@@ -766,8 +757,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	public <T> Mono<T> findOne(Query query, Class<T> entityClass, String collectionName) {
 
 		if (ObjectUtils.isEmpty(query.getSortObject())) {
-			return doFindOne(collectionName, ReactiveCollectionPreparerDelegate.of(query), query.getQueryObject(),
-					query.getFieldsObject(), entityClass, new QueryFindPublisherPreparer(query, entityClass));
+			return doFindOne(collectionName, query.getQueryObject(), query.getFieldsObject(), entityClass,
+					new QueryFindPublisherPreparer(query, entityClass));
 		}
 
 		query.limit(1);
@@ -793,11 +784,10 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 		return createFlux(collectionName, collection -> {
 
-			ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(query);
 			QueryContext queryContext = queryOperations.createQueryContext(query);
 			Document filter = queryContext.getMappedQuery(entityClass, this::getPersistentEntity);
 
-			FindPublisher<Document> findPublisher = collectionPreparer.prepare(collection).find(filter, Document.class)
+			FindPublisher<Document> findPublisher = collection.find(filter, Document.class)
 					.projection(new Document("_id", 1));
 
 			if (LOGGER.isDebugEnabled()) {
@@ -822,8 +812,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			return findAll(entityClass, collectionName);
 		}
 
-		return doFind(collectionName, ReactiveCollectionPreparerDelegate.of(query), query.getQueryObject(),
-				query.getFieldsObject(), entityClass, new QueryFindPublisherPreparer(query, entityClass));
+		return doFind(collectionName, query.getQueryObject(), query.getFieldsObject(), entityClass,
+				new QueryFindPublisherPreparer(query, entityClass));
 	}
 
 	@Override
@@ -836,8 +826,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 		String idKey = operations.getIdPropertyName(entityClass);
 
-		return doFindOne(collectionName, CollectionPreparer.identity(), new Document(idKey, id), null, entityClass,
-				(Collation) null);
+		return doFindOne(collectionName, new Document(idKey, id), null, entityClass, (Collation) null);
 	}
 
 	@Override
@@ -862,7 +851,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		Document mappedQuery = distinctQueryContext.getMappedQuery(entity);
 		String mappedFieldName = distinctQueryContext.getMappedFieldName(entity);
 		Class<T> mongoDriverCompatibleType = distinctQueryContext.getDriverCompatibleClass(resultClass);
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(query);
 
 		Flux<?> result = execute(collectionName, collection -> {
 
@@ -872,9 +860,11 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			}
 
 			FindPublisherPreparer preparer = new QueryFindPublisherPreparer(query, entityClass);
+			if (preparer.hasReadPreference()) {
+				collection = collection.withReadPreference(preparer.getReadPreference());
+			}
 
-			DistinctPublisher<T> publisher = collectionPreparer.prepare(collection).distinct(mappedFieldName, mappedQuery,
-					mongoDriverCompatibleType);
+			DistinctPublisher<T> publisher = collection.distinct(mappedFieldName, mappedQuery, mongoDriverCompatibleType);
 			distinctQueryContext.applyCollation(entityClass, publisher::collation);
 			return publisher;
 		});
@@ -940,8 +930,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			boolean isOutOrMerge, AggregationOptions options, ReadDocumentCallback<O> readCallback,
 			@Nullable Class<?> inputType) {
 
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(options);
-		AggregatePublisher<Document> cursor = collectionPreparer.prepare(collection).aggregate(pipeline, Document.class)
+		AggregatePublisher<Document> cursor = collection.aggregate(pipeline, Document.class)
 				.allowDiskUse(options.isAllowDiskUse());
 
 		if (options.getCursorBatchSize() != null) {
@@ -999,19 +988,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		GeoNearResultDocumentCallback<T> callback = new GeoNearResultDocumentCallback<>(distanceField,
 				new ProjectingReadCallback<>(mongoConverter, projection, collection), near.getMetric());
 
-		Builder optionsBuilder = AggregationOptions.builder();
-		if (near.hasReadPreference()) {
-			optionsBuilder.readPreference(near.getReadPreference());
-		}
-
-		if(near.hasReadConcern()) {
-			optionsBuilder.readConcern(near.getReadConcern());
-		}
-
-		optionsBuilder.collation(near.getCollation());
-
 		Aggregation $geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, distanceField))
-				.withOptions(optionsBuilder.build());
+				.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
 
 		return aggregate($geoNear, collection, Document.class) //
 				.concatMap(callback::doWith);
@@ -1051,8 +1029,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			operations.forType(entityClass).getCollation(query).ifPresent(optionsToUse::collation);
 		}
 
-		return doFindAndModify(collectionName, ReactiveCollectionPreparerDelegate.of(query), query.getQueryObject(),
-				query.getFieldsObject(), getMappedSortObject(query, entityClass), entityClass, update, optionsToUse);
+		return doFindAndModify(collectionName, query.getQueryObject(), query.getFieldsObject(),
+				getMappedSortObject(query, entityClass), entityClass, update, optionsToUse);
 	}
 
 	@Override
@@ -1076,7 +1054,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		Document mappedQuery = queryContext.getMappedQuery(entity);
 		Document mappedFields = queryContext.getMappedFields(entity, projection);
 		Document mappedSort = queryContext.getMappedSort(entity);
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(query);
 
 		return Mono.defer(() -> {
 
@@ -1094,9 +1071,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 								mapped.getCollection()));
 			}).flatMap(it -> {
 
-				Mono<T> afterFindAndReplace = doFindAndReplace(it.getCollection(), collectionPreparer, mappedQuery,
-						mappedFields, mappedSort, queryContext.getCollation(entityType).orElse(null), entityType, it.getTarget(),
-						options, projection);
+				Mono<T> afterFindAndReplace = doFindAndReplace(it.getCollection(), mappedQuery, mappedFields, mappedSort,
+						queryContext.getCollation(entityType).orElse(null), entityType, it.getTarget(), options, projection);
 				return afterFindAndReplace.flatMap(saved -> {
 					maybeEmitEvent(new AfterSaveEvent<>(saved, it.getTarget(), it.getCollection()));
 					return maybeCallAfterSave(saved, it.getTarget(), it.getCollection());
@@ -1114,9 +1090,9 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	public <T> Mono<T> findAndRemove(Query query, Class<T> entityClass, String collectionName) {
 
 		operations.forType(entityClass).getCollation(query);
-		return doFindAndRemove(collectionName, ReactiveCollectionPreparerDelegate.of(query), query.getQueryObject(),
-				query.getFieldsObject(), getMappedSortObject(query, entityClass),
-				operations.forType(entityClass).getCollation(query).orElse(null), entityClass);
+		return doFindAndRemove(collectionName, query.getQueryObject(), query.getFieldsObject(),
+				getMappedSortObject(query, entityClass), operations.forType(entityClass).getCollation(query).orElse(null),
+				entityClass);
 	}
 
 	/*
@@ -1456,7 +1432,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 				Document dbDoc = entity.toMappedDocument(writer).getDocument();
 				maybeEmitEvent(new BeforeSaveEvent<T>(toConvert, dbDoc, collectionName));
 
-				return maybeCallBeforeSave(toConvert, dbDoc, collectionName).flatMap(it -> {
+				return maybeCallBeforeSave(toConvert, dbDoc, collectionName)
+						.flatMap(it -> {
 
 					return saveDocument(collectionName, dbDoc, it.getClass()).flatMap(id -> {
 
@@ -1469,6 +1446,26 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		});
 	}
 
+	private Mono<Document> resolveValues(Mono<Document> document) {
+		return document.flatMap(source -> {
+			for (Entry<String, Object> entry : source.entrySet()) {
+				if (entry.getValue()instanceof Mono<?> valueMono) {
+					return valueMono.flatMap(value -> {
+						source.put(entry.getKey(), value);
+						return resolveValues(Mono.just(source));
+					});
+				}
+				if (entry.getValue()instanceof Document nested) {
+					return resolveValues(Mono.just(nested)).map(it -> {
+						source.put(entry.getKey(), it);
+						return source;
+					});
+				}
+			}
+			return Mono.just(source);
+		});
+	}
+
 	protected Mono<Object> insertDocument(String collectionName, Document dbDoc, Class<?> entityClass) {
 
 		if (LOGGER.isDebugEnabled()) {
@@ -1552,16 +1549,16 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 					? collection //
 					: collection.withWriteConcern(writeConcernToUse);
 
-			Publisher<?> publisher;
+			Publisher<?> publisher = null;
+			Mono<Document> resolved = resolveValues(Mono.just(queryOperations.createInsertContext(mapped).prepareId(entityClass).getDocument()));
 			if (!mapped.hasId()) {
-				publisher = collectionToUse
-						.insertOne(queryOperations.createInsertContext(mapped).prepareId(entityClass).getDocument());
+				publisher = resolved.flatMap(it -> Mono.from(collectionToUse.insertOne(it)));
 			} else {
 
 				MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 				UpdateContext updateContext = queryOperations.replaceSingleContext(mapped, true);
 				Document filter = updateContext.getMappedQuery(entity);
-				Document replacement = updateContext.getMappedUpdate(entity);
+				Mono<Document> replacement = resolveValues(Mono.just(updateContext.getMappedUpdate(entity)));
 
 				Mono<Document> deferredFilter;
 
@@ -1572,14 +1569,17 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 						deferredFilter = Mono
 								.from(
 										collection.find(filter, Document.class).projection(updateContext.getMappedShardKey(entity)).first())
-								.defaultIfEmpty(replacement).map(it -> updateContext.applyShardKey(entity, filter, it));
+								.switchIfEmpty(replacement)
+								.map(it -> {
+									return updateContext.applyShardKey(entity, filter, it);
+								});
 					}
 				} else {
 					deferredFilter = Mono.just(filter);
 				}
 
-				publisher = deferredFilter.flatMapMany(
-						it -> collectionToUse.replaceOne(it, replacement, updateContext.getReplaceOptions(entityClass)));
+				publisher = deferredFilter.zipWith(replacement).flatMapMany(
+						it -> collectionToUse.replaceOne(it.getT1(), it.getT2(), updateContext.getReplaceOptions(entityClass)));
 			}
 
 			return Mono.from(publisher).map(o -> mapped.getId());
@@ -1824,14 +1824,12 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		MongoAction mongoAction = new MongoAction(writeConcern, MongoActionOperation.REMOVE, collectionName, entityClass,
 				null, removeQuery);
 		WriteConcern writeConcernToUse = prepareWriteConcern(mongoAction);
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(query);
 
 		return execute(collectionName, collection -> {
 
 			maybeEmitEvent(new BeforeDeleteEvent<>(removeQuery, entityClass, collectionName));
 
-			MongoCollection<Document> collectionToUse = collectionPreparer
-					.prepare(prepareCollection(collection, writeConcernToUse));
+			MongoCollection<Document> collectionToUse = prepareCollection(collection, writeConcernToUse);
 
 			if (LOGGER.isDebugEnabled()) {
 				LOGGER.debug(String.format("Remove using query: %s in collection: %s.", serializeToJsonSafely(removeQuery),
@@ -1866,9 +1864,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 	@Override
 	public <T> Flux<T> findAll(Class<T> entityClass, String collectionName) {
-		return executeFindMultiInternal(new FindCallback(CollectionPreparer.identity(), null),
-				FindPublisherPreparer.NO_OP_PREPARER, new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName),
-				collectionName);
+		return executeFindMultiInternal(new FindCallback(null), FindPublisherPreparer.NO_OP_PREPARER,
+				new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName), collectionName);
 	}
 
 	@Override
@@ -1895,19 +1892,17 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	@Override
 	public <T> Flux<T> tail(@Nullable Query query, Class<T> entityClass, String collectionName) {
 
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(query);
 		if (query == null) {
 
 			LOGGER.debug(String.format("Tail for class: %s in collection: %s", entityClass, collectionName));
 
 			return executeFindMultiInternal(
-					collection -> new FindCallback(collectionPreparer, null).doInCollection(collection)
-							.cursorType(CursorType.TailableAwait),
+					collection -> new FindCallback(null).doInCollection(collection).cursorType(CursorType.TailableAwait),
 					FindPublisherPreparer.NO_OP_PREPARER, new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName),
 					collectionName);
 		}
 
-		return doFind(collectionName, collectionPreparer, query.getQueryObject(), query.getFieldsObject(), entityClass,
+		return doFind(collectionName, query.getQueryObject(), query.getFieldsObject(), entityClass,
 				new TailingQueryFindPublisherPreparer(query, entityClass));
 	}
 
@@ -1991,14 +1986,12 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 		assertLocalFunctionNames(mapFunction, reduceFunction);
 
-		ReactiveCollectionPreparerDelegate collectionPreparer = ReactiveCollectionPreparerDelegate.of(filterQuery);
 		return createFlux(inputCollectionName, collection -> {
 
 			Document mappedQuery = queryMapper.getMappedObject(filterQuery.getQueryObject(),
 					mappingContext.getPersistentEntity(domainType));
 
-			MapReducePublisher<Document> publisher = collectionPreparer.prepare(collection).mapReduce(mapFunction,
-					reduceFunction, Document.class);
+			MapReducePublisher<Document> publisher = collection.mapReduce(mapFunction, reduceFunction, Document.class);
 
 			publisher.filter(mappedQuery);
 
@@ -2165,18 +2158,16 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * The query document is specified as a standard {@link Document} and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
 	 * @param entityClass the parameterized type of the returned list.
 	 * @param collation can be {@literal null}.
 	 * @return the {@link List} of converted objects.
 	 */
-	protected <T> Mono<T> doFindOne(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, @Nullable Document fields,
+	protected <T> Mono<T> doFindOne(String collectionName, Document query, @Nullable Document fields,
 			Class<T> entityClass, @Nullable Collation collation) {
 
-		return doFindOne(collectionName, collectionPreparer, query, fields, entityClass,
+		return doFindOne(collectionName, query, fields, entityClass,
 				findPublisher -> collation != null ? findPublisher.collation(collation.toMongoCollation()) : findPublisher);
 	}
 
@@ -2185,7 +2176,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * The query document is specified as a standard {@link Document} and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
 	 * @param entityClass the parameterized type of the returned list.
@@ -2193,8 +2183,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @return the {@link List} of converted objects.
 	 * @since 2.2
 	 */
-	protected <T> Mono<T> doFindOne(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, @Nullable Document fields,
+	protected <T> Mono<T> doFindOne(String collectionName, Document query, @Nullable Document fields,
 			Class<T> entityClass, FindPublisherPreparer preparer) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
@@ -2209,7 +2198,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 					serializeToJsonSafely(query), mappedFields, entityClass, collectionName));
 		}
 
-		return executeFindOneInternal(new FindOneCallback(collectionPreparer, mappedQuery, mappedFields, preparer),
+		return executeFindOneInternal(new FindOneCallback(mappedQuery, mappedFields, preparer),
 				new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName), collectionName);
 	}
 
@@ -2218,15 +2207,13 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * query document is specified as a standard Document and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record
 	 * @param fields the document that specifies the fields to be returned
 	 * @param entityClass the parameterized type of the returned list.
 	 * @return the List of converted objects.
 	 */
-	protected <T> Flux<T> doFind(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<T> entityClass) {
-		return doFind(collectionName, collectionPreparer, query, fields, entityClass, null,
+	protected <T> Flux<T> doFind(String collectionName, Document query, Document fields, Class<T> entityClass) {
+		return doFind(collectionName, query, fields, entityClass, null,
 				new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName));
 	}
 
@@ -2236,7 +2223,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * specified as a standard Document and so is the fields specification.
 	 *
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param query the query document that specifies the criteria used to find a record.
 	 * @param fields the document that specifies the fields to be returned.
 	 * @param entityClass the parameterized type of the returned list.
@@ -2244,15 +2230,14 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 *          the result set, (apply limits, skips and so on).
 	 * @return the {@link List} of converted objects.
 	 */
-	protected <T> Flux<T> doFind(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<T> entityClass, FindPublisherPreparer preparer) {
-		return doFind(collectionName, collectionPreparer, query, fields, entityClass, preparer,
+	protected <T> Flux<T> doFind(String collectionName, Document query, Document fields, Class<T> entityClass,
+			FindPublisherPreparer preparer) {
+		return doFind(collectionName, query, fields, entityClass, preparer,
 				new ReadDocumentCallback<>(mongoConverter, entityClass, collectionName));
 	}
 
-	protected <S, T> Flux<T> doFind(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields,
-			Class<S> entityClass, @Nullable FindPublisherPreparer preparer, DocumentCallback<T> objectCallback) {
+	protected <S, T> Flux<T> doFind(String collectionName, Document query, Document fields, Class<S> entityClass,
+			@Nullable FindPublisherPreparer preparer, DocumentCallback<T> objectCallback) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
@@ -2265,8 +2250,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 					serializeToJsonSafely(mappedQuery), mappedFields, entityClass, collectionName));
 		}
 
-		return executeFindMultiInternal(new FindCallback(collectionPreparer, mappedQuery, mappedFields), preparer,
-				objectCallback, collectionName);
+		return executeFindMultiInternal(new FindCallback(mappedQuery, mappedFields), preparer, objectCallback,
+				collectionName);
 	}
 
 	/**
@@ -2275,8 +2260,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 *
 	 * @since 2.0
 	 */
-	<S, T> Flux<T> doFind(String collectionName, CollectionPreparer<MongoCollection<Document>> collectionPreparer,
-			Document query, Document fields, Class<S> sourceClass, Class<T> targetClass, FindPublisherPreparer preparer) {
+	<S, T> Flux<T> doFind(String collectionName, Document query, Document fields, Class<S> sourceClass,
+			Class<T> targetClass, FindPublisherPreparer preparer) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(sourceClass);
 		EntityProjection<T, S> projection = operations.introspectProjection(targetClass, sourceClass);
@@ -2290,7 +2275,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 					serializeToJsonSafely(mappedQuery), mappedFields, sourceClass, collectionName));
 		}
 
-		return executeFindMultiInternal(new FindCallback(collectionPreparer, mappedQuery, mappedFields), preparer,
+		return executeFindMultiInternal(new FindCallback(mappedQuery, mappedFields), preparer,
 				new ProjectingReadCallback<>(mongoConverter, projection, collectionName), collectionName);
 	}
 
@@ -2308,15 +2293,13 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * The first document that matches the query is returned and also removed from the collection in the database. <br />
 	 * The query document is specified as a standard Document and so is the fields specification.
 	 *
-	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
-	 * @param query the query document that specifies the criteria used to find a record.
-	 * @param collation collation.
+	 * @param collectionName name of the collection to retrieve the objects from
+	 * @param query the query document that specifies the criteria used to find a record
+	 * @param collation collation
 	 * @param entityClass the parameterized type of the returned list.
 	 * @return the List of converted objects.
 	 */
-	protected <T> Mono<T> doFindAndRemove(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields, Document sort,
+	protected <T> Mono<T> doFindAndRemove(String collectionName, Document query, Document fields, Document sort,
 			@Nullable Collation collation, Class<T> entityClass) {
 
 		if (LOGGER.isDebugEnabled()) {
@@ -2326,13 +2309,12 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
-		return executeFindOneInternal(new FindAndRemoveCallback(collectionPreparer,
-				queryMapper.getMappedObject(query, entity), fields, sort, collation),
+		return executeFindOneInternal(
+				new FindAndRemoveCallback(queryMapper.getMappedObject(query, entity), fields, sort, collation),
 				new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName), collectionName);
 	}
 
-	protected <T> Mono<T> doFindAndModify(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields, Document sort,
+	protected <T> Mono<T> doFindAndModify(String collectionName, Document query, Document fields, Document sort,
 			Class<T> entityClass, UpdateDefinition update, FindAndModifyOptions options) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
@@ -2353,7 +2335,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			}
 
 			return executeFindOneInternal(
-					new FindAndModifyCallback(collectionPreparer, mappedQuery, fields, sort, mappedUpdate,
+					new FindAndModifyCallback(mappedQuery, fields, sort, mappedUpdate,
 							update.getArrayFilters().stream().map(ArrayFilter::asDocument).collect(Collectors.toList()), options),
 					new ReadDocumentCallback<>(this.mongoConverter, entityClass, collectionName), collectionName);
 		});
@@ -2363,7 +2345,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * Customize this part for findAndReplace.
 	 *
 	 * @param collectionName The name of the collection to perform the operation in.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param mappedQuery the query to look up documents.
 	 * @param mappedFields the fields to project the result to.
 	 * @param mappedSort the sort to be applied when executing the query.
@@ -2376,22 +2357,20 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 *         {@literal false} and {@link FindAndReplaceOptions#isUpsert() upsert} is {@literal false}.
 	 * @since 2.1
 	 */
-	protected <T> Mono<T> doFindAndReplace(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document mappedQuery, Document mappedFields,
+	protected <T> Mono<T> doFindAndReplace(String collectionName, Document mappedQuery, Document mappedFields,
 			Document mappedSort, com.mongodb.client.model.Collation collation, Class<?> entityType, Document replacement,
 			FindAndReplaceOptions options, Class<T> resultType) {
 
 		EntityProjection<T, ?> projection = operations.introspectProjection(resultType, entityType);
 
-		return doFindAndReplace(collectionName, collectionPreparer, mappedQuery, mappedFields, mappedSort, collation,
-				entityType, replacement, options, projection);
+		return doFindAndReplace(collectionName, mappedQuery, mappedFields, mappedSort, collation, entityType, replacement,
+				options, projection);
 	}
 
 	/**
 	 * Customize this part for findAndReplace.
 	 *
 	 * @param collectionName The name of the collection to perform the operation in.
-	 * @param collectionPreparer the preparer to prepare the collection for the actual use.
 	 * @param mappedQuery the query to look up documents.
 	 * @param mappedFields the fields to project the result to.
 	 * @param mappedSort the sort to be applied when executing the query.
@@ -2404,8 +2383,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 *         {@literal false} and {@link FindAndReplaceOptions#isUpsert() upsert} is {@literal false}.
 	 * @since 3.4
 	 */
-	private <T> Mono<T> doFindAndReplace(String collectionName,
-			CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document mappedQuery, Document mappedFields,
+	private <T> Mono<T> doFindAndReplace(String collectionName, Document mappedQuery, Document mappedFields,
 			Document mappedSort, com.mongodb.client.model.Collation collation, Class<?> entityType, Document replacement,
 			FindAndReplaceOptions options, EntityProjection<T, ?> projection) {
 
@@ -2419,8 +2397,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 						serializeToJsonSafely(replacement), collectionName));
 			}
 
-			return executeFindOneInternal(new FindAndReplaceCallback(collectionPreparer, mappedQuery, mappedFields,
-					mappedSort, replacement, collation, options),
+			return executeFindOneInternal(
+					new FindAndReplaceCallback(mappedQuery, mappedFields, mappedSort, replacement, collation, options),
 					new ProjectingReadCallback<>(this.mongoConverter, projection, collectionName), collectionName);
 
 		});
@@ -2498,12 +2476,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @param collection
 	 */
 	protected MongoCollection<Document> prepareCollection(MongoCollection<Document> collection) {
-
-		if (this.readPreference != null && this.readPreference != collection.getReadPreference()) {
-			return collection.withReadPreference(readPreference);
-		}
-
-		return collection;
+		return this.readPreference != null ? collection.withReadPreference(readPreference) : collection;
 	}
 
 	/**
@@ -2673,14 +2646,11 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	private static class FindOneCallback implements ReactiveCollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Optional<Document> fields;
 		private final FindPublisherPreparer preparer;
 
-		FindOneCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				@Nullable Document fields, FindPublisherPreparer preparer) {
-			this.collectionPreparer = collectionPreparer;
+		FindOneCallback(Document query, @Nullable Document fields, FindPublisherPreparer preparer) {
 			this.query = query;
 			this.fields = Optional.ofNullable(fields);
 			this.preparer = preparer;
@@ -2697,8 +2667,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 								serializeToJsonSafely(fields.orElseGet(Document::new)), collection.getNamespace().getFullName()));
 			}
 
-			FindPublisher<Document> publisher = preparer.initiateFind(collectionPreparer.prepare(collection),
-					col -> col.find(query, Document.class));
+			FindPublisher<Document> publisher = preparer.initiateFind(collection, col -> col.find(query, Document.class));
 
 			if (fields.isPresent()) {
 				publisher = publisher.projection(fields.get());
@@ -2716,17 +2685,15 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	private static class FindCallback implements ReactiveCollectionQueryCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
-
 		private final @Nullable Document query;
 		private final @Nullable Document fields;
 
-		FindCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, @Nullable Document query) {
-			this(collectionPreparer, query, null);
+		FindCallback(@Nullable Document query) {
+			this(query, null);
 		}
 
-		FindCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query, Document fields) {
-			this.collectionPreparer = collectionPreparer;
+		FindCallback(Document query, Document fields) {
+
 			this.query = query;
 			this.fields = fields;
 		}
@@ -2734,12 +2701,11 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		@Override
 		public FindPublisher<Document> doInCollection(MongoCollection<Document> collection) {
 
-			MongoCollection<Document> collectionToUse = collectionPreparer.prepare(collection);
 			FindPublisher<Document> findPublisher;
 			if (ObjectUtils.isEmpty(query)) {
-				findPublisher = collectionToUse.find(Document.class);
+				findPublisher = collection.find(Document.class);
 			} else {
-				findPublisher = collectionToUse.find(query, Document.class);
+				findPublisher = collection.find(query, Document.class);
 			}
 
 			if (ObjectUtils.isEmpty(fields)) {
@@ -2758,15 +2724,13 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	private static class FindAndRemoveCallback implements ReactiveCollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
 		private final Optional<Collation> collation;
 
-		FindAndRemoveCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, @Nullable Collation collation) {
-			this.collectionPreparer = collectionPreparer;
+		FindAndRemoveCallback(Document query, Document fields, Document sort, @Nullable Collation collation) {
+
 			this.query = query;
 			this.fields = fields;
 			this.sort = sort;
@@ -2780,7 +2744,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			FindOneAndDeleteOptions findOneAndDeleteOptions = convertToFindOneAndDeleteOptions(fields, sort);
 			collation.map(Collation::toMongoCollation).ifPresent(findOneAndDeleteOptions::collation);
 
-			return collectionPreparer.prepare(collection).findOneAndDelete(query, findOneAndDeleteOptions);
+			return collection.findOneAndDelete(query, findOneAndDeleteOptions);
 		}
 	}
 
@@ -2789,7 +2753,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	private static class FindAndModifyCallback implements ReactiveCollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
@@ -2797,10 +2760,9 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		private final List<Document> arrayFilters;
 		private final FindAndModifyOptions options;
 
-		FindAndModifyCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, Object update, List<Document> arrayFilters, FindAndModifyOptions options) {
+		FindAndModifyCallback(Document query, Document fields, Document sort, Object update, List<Document> arrayFilters,
+				FindAndModifyOptions options) {
 
-			this.collectionPreparer = collectionPreparer;
 			this.query = query;
 			this.fields = fields;
 			this.sort = sort;
@@ -2813,22 +2775,21 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		public Publisher<Document> doInCollection(MongoCollection<Document> collection)
 				throws MongoException, DataAccessException {
 
-			MongoCollection<Document> collectionToUse = collectionPreparer.prepare(collection);
 			if (options.isRemove()) {
 				FindOneAndDeleteOptions findOneAndDeleteOptions = convertToFindOneAndDeleteOptions(fields, sort);
 
 				findOneAndDeleteOptions = options.getCollation().map(Collation::toMongoCollation)
 						.map(findOneAndDeleteOptions::collation).orElse(findOneAndDeleteOptions);
 
-				return collectionToUse.findOneAndDelete(query, findOneAndDeleteOptions);
+				return collection.findOneAndDelete(query, findOneAndDeleteOptions);
 			}
 
 			FindOneAndUpdateOptions findOneAndUpdateOptions = convertToFindOneAndUpdateOptions(options, fields, sort,
 					arrayFilters);
 			if (update instanceof Document) {
-				return collectionToUse.findOneAndUpdate(query, (Document) update, findOneAndUpdateOptions);
+				return collection.findOneAndUpdate(query, (Document) update, findOneAndUpdateOptions);
 			} else if (update instanceof List) {
-				return collectionToUse.findOneAndUpdate(query, (List<Document>) update, findOneAndUpdateOptions);
+				return collection.findOneAndUpdate(query, (List<Document>) update, findOneAndUpdateOptions);
 			}
 
 			return Flux
@@ -2867,7 +2828,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	private static class FindAndReplaceCallback implements ReactiveCollectionCallback<Document> {
 
-		private final CollectionPreparer<MongoCollection<Document>> collectionPreparer;
 		private final Document query;
 		private final Document fields;
 		private final Document sort;
@@ -2875,10 +2835,9 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		private final @Nullable com.mongodb.client.model.Collation collation;
 		private final FindAndReplaceOptions options;
 
-		FindAndReplaceCallback(CollectionPreparer<MongoCollection<Document>> collectionPreparer, Document query,
-				Document fields, Document sort, Document update, com.mongodb.client.model.Collation collation,
-				FindAndReplaceOptions options) {
-			this.collectionPreparer = collectionPreparer;
+		FindAndReplaceCallback(Document query, Document fields, Document sort, Document update,
+				com.mongodb.client.model.Collation collation, FindAndReplaceOptions options) {
+
 			this.query = query;
 			this.fields = fields;
 			this.sort = sort;
@@ -2892,7 +2851,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 				throws MongoException, DataAccessException {
 
 			FindOneAndReplaceOptions findOneAndReplaceOptions = convertToFindOneAndReplaceOptions(options, fields, sort);
-			return collectionPreparer.prepare(collection).findOneAndReplace(query, update, findOneAndReplaceOptions);
+			return collection.findOneAndReplace(query, update, findOneAndReplaceOptions);
 		}
 
 		private FindOneAndReplaceOptions convertToFindOneAndReplaceOptions(FindAndReplaceOptions options, Document fields,
@@ -3158,6 +3117,11 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 			return findPublisherToUse;
 		}
 
+		@Override
+		public ReadPreference getReadPreference() {
+			return query.getMeta().getFlags().contains(CursorOption.SECONDARY_READS) ? ReadPreference.primaryPreferred()
+					: null;
+		}
 	}
 
 	class TailingQueryFindPublisherPreparer extends QueryFindPublisherPreparer {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReadConcernAware.java

@@ -1,46 +0,0 @@
-/*
- * Copyright 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.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.data.mongodb.core;
-
-import org.springframework.lang.Nullable;
-
-import com.mongodb.ReadConcern;
-
-/**
- * Interface to be implemented by any object that wishes to expose the {@link ReadConcern}.
- * <p>
- * Typically implemented by cursor or query preparer objects.
- *
- * @author Mark Paluch
- * @since 4.1
- * @see org.springframework.data.mongodb.core.query.Query
- * @see org.springframework.data.mongodb.core.aggregation.AggregationOptions
- */
-public interface ReadConcernAware {
-
-	/**
-	 * @return {@literal true} if a {@link ReadConcern} is set.
-	 */
-	default boolean hasReadConcern() {
-		return getReadConcern() != null;
-	}
-
-	/**
-	 * @return the {@link ReadConcern} to apply or {@literal null} if none set.
-	 */
-	@Nullable
-	ReadConcern getReadConcern();
-}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReadPreferenceAware.java

@@ -27,8 +27,6 @@ import com.mongodb.ReadPreference;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @since 2.2
- * @see org.springframework.data.mongodb.core.query.Query
- * @see org.springframework.data.mongodb.core.aggregation.AggregationOptions
  */
 public interface ReadPreferenceAware {
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Aggregation.java

@@ -28,7 +28,6 @@ import org.springframework.data.mongodb.core.aggregation.AddFieldsOperation.AddF
 import org.springframework.data.mongodb.core.aggregation.CountOperation.CountOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.FacetOperation.FacetOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.GraphLookupOperation.StartWithBuilder;
-import org.springframework.data.mongodb.core.aggregation.LookupOperation.LookupOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.MergeOperation.MergeOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.ReplaceRootOperation.ReplaceRootDocumentOperationBuilder;
 import org.springframework.data.mongodb.core.aggregation.ReplaceRootOperation.ReplaceRootOperationBuilder;
@@ -51,7 +50,6 @@ import org.springframework.util.Assert;
  * @author Nikolay Bogdanov
  * @author Gustavo de Geus
  * @author Jérôme Guyon
- * @author Sangyong Choi
  * @since 1.3
  */
 public class Aggregation {
@@ -666,23 +664,6 @@ public class Aggregation {
 		return new LookupOperation(from, localField, foreignField, as);
 	}
 
-	/**
-	 * Entrypoint for creating {@link LookupOperation $lookup} using a fluent builder API.
-	 * <pre class="code">
-	 * Aggregation.lookup().from("restaurants")
-	 * 	.localField("restaurant_name")
-	 * 	.foreignField("name")
-	 * 	.let(newVariable("orders_drink").forField("drink"))
-	 * 	.pipeline(match(ctx -> new Document("$expr", new Document("$in", List.of("$$orders_drink", "$beverages")))))
-	 * 	.as("matches")
-	 * </pre>
-	 * @return new instance of {@link LookupOperationBuilder}.
-	 * @since 4.1
-	 */
-	public static LookupOperationBuilder lookup() {
-		return new LookupOperationBuilder();
-	}
-
 	/**
 	 * Creates a new {@link CountOperationBuilder}.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationOptions.java

@@ -19,16 +19,11 @@ import java.time.Duration;
 import java.util.Optional;
 
 import org.bson.Document;
-import org.springframework.data.mongodb.core.ReadConcernAware;
-import org.springframework.data.mongodb.core.ReadPreferenceAware;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.util.BsonUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
-import com.mongodb.ReadConcern;
-import com.mongodb.ReadPreference;
-
 /**
  * Holds a set of configurable aggregation options that can be used within an aggregation pipeline. A list of support
  * aggregation options can be found in the MongoDB reference documentation
@@ -44,7 +39,7 @@ import com.mongodb.ReadPreference;
  * @see TypedAggregation#withOptions(AggregationOptions)
  * @since 1.6
  */
-public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware {
+public class AggregationOptions {
 
 	private static final String BATCH_SIZE = "batchSize";
 	private static final String CURSOR = "cursor";
@@ -61,10 +56,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 	private final Optional<Collation> collation;
 	private final Optional<String> comment;
 	private final Optional<Object> hint;
-
-	private Optional<ReadConcern> readConcern;
-
-	private Optional<ReadPreference> readPreference;
 	private Duration maxTime = Duration.ZERO;
 	private ResultOptions resultOptions = ResultOptions.READ;
 	private DomainTypeMapping domainTypeMapping = DomainTypeMapping.RELAXED;
@@ -132,8 +123,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 		this.collation = Optional.ofNullable(collation);
 		this.comment = Optional.ofNullable(comment);
 		this.hint = Optional.ofNullable(hint);
-		this.readConcern = Optional.empty();
-		this.readPreference = Optional.empty();
 	}
 
 	/**
@@ -279,26 +268,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 		return hint;
 	}
 
-	@Override
-	public boolean hasReadConcern() {
-		return readConcern.isPresent();
-	}
-
-	@Override
-	public ReadConcern getReadConcern() {
-		return readConcern.orElse(null);
-	}
-
-	@Override
-	public boolean hasReadPreference() {
-		return readPreference.isPresent();
-	}
-
-	@Override
-	public ReadPreference getReadPreference() {
-		return readPreference.orElse(null);
-	}
-
 	/**
 	 * @return the time limit for processing. {@link Duration#ZERO} is used for the default unbounded behavior.
 	 * @since 3.0
@@ -416,8 +385,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 		private @Nullable Collation collation;
 		private @Nullable String comment;
 		private @Nullable Object hint;
-		private @Nullable ReadConcern readConcern;
-		private @Nullable ReadPreference readPreference;
 		private @Nullable Duration maxTime;
 		private @Nullable ResultOptions resultOptions;
 		private @Nullable DomainTypeMapping domainTypeMapping;
@@ -523,32 +490,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 			return this;
 		}
 
-		/**
-		 * Define a {@link ReadConcern} to apply to the aggregation.
-		 *
-		 * @param readConcern can be {@literal null}.
-		 * @return this.
-		 * @since 4.1
-		 */
-		public Builder readConcern(@Nullable ReadConcern readConcern) {
-
-			this.readConcern = readConcern;
-			return this;
-		}
-
-		/**
-		 * Define a {@link ReadPreference} to apply to the aggregation.
-		 *
-		 * @param readPreference can be {@literal null}.
-		 * @return this.
-		 * @since 4.1
-		 */
-		public Builder readPreference(@Nullable ReadPreference readPreference) {
-
-			this.readPreference = readPreference;
-			return this;
-		}
-
 		/**
 		 * Set the time limit for processing.
 		 *
@@ -632,12 +573,6 @@ public class AggregationOptions implements ReadConcernAware, ReadPreferenceAware
 			if (domainTypeMapping != null) {
 				options.domainTypeMapping = domainTypeMapping;
 			}
-			if (readConcern != null) {
-				options.readConcern = Optional.of(readConcern);
-			}
-			if (readPreference != null) {
-				options.readPreference = Optional.of(readPreference);
-			}
 
 			return options;
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/LookupOperation.java

@@ -15,44 +15,28 @@
  */
 package org.springframework.data.mongodb.core.aggregation;
 
-import java.util.function.Supplier;
-
 import org.bson.Document;
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
 import org.springframework.data.mongodb.core.aggregation.FieldsExposingAggregationOperation.InheritsFieldsAggregationOperation;
-import org.springframework.data.mongodb.core.aggregation.VariableOperators.Let;
-import org.springframework.data.mongodb.core.aggregation.VariableOperators.Let.ExpressionVariable;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
- * Encapsulates the aggregation framework {@code $lookup}-operation. We recommend to use the builder provided via
- * {@link #newLookup()} instead of creating instances of this class directly.
+ * Encapsulates the aggregation framework {@code $lookup}-operation. We recommend to use the static factory method
+ * {@link Aggregation#lookup(String, String, String, String)} instead of creating instances of this class directly.
  *
  * @author Alessio Fachechi
  * @author Christoph Strobl
  * @author Mark Paluch
- * @author Sangyong Choi
  * @since 1.9
  * @see <a href="https://docs.mongodb.com/manual/reference/operator/aggregation/lookup/">MongoDB Aggregation Framework:
  *      $lookup</a>
  */
 public class LookupOperation implements FieldsExposingAggregationOperation, InheritsFieldsAggregationOperation {
 
-	private final String from;
-
-	@Nullable //
+	private final Field from;
 	private final Field localField;
-
-	@Nullable //
 	private final Field foreignField;
-
-	@Nullable //
-	private final Let let;
-
-	@Nullable //
-	private final AggregationPipeline pipeline;
-
 	private final ExposedField as;
 
 	/**
@@ -64,55 +48,16 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 	 * @param as must not be {@literal null}.
 	 */
 	public LookupOperation(Field from, Field localField, Field foreignField, Field as) {
-		this(((Supplier<String>) () -> {
-
-			Assert.notNull(from, "From must not be null");
-			return from.getTarget();
-		}).get(), localField, foreignField, null, null, as);
-	}
-
-	/**
-	 * Creates a new {@link LookupOperation} for the given combination of {@link Field}s and {@link AggregationPipeline
-	 * pipeline}.
-	 *
-	 * @param from must not be {@literal null}.
-	 * @param let must not be {@literal null}.
-	 * @param as must not be {@literal null}.
-	 * @since 4.1
-	 */
-	public LookupOperation(String from, @Nullable Let let, AggregationPipeline pipeline, Field as) {
-		this(from, null, null, let, pipeline, as);
-	}
-
-	/**
-	 * Creates a new {@link LookupOperation} for the given combination of {@link Field}s and {@link AggregationPipeline
-	 * pipeline}.
-	 *
-	 * @param from must not be {@literal null}.
-	 * @param localField can be {@literal null} if {@literal pipeline} is present.
-	 * @param foreignField can be {@literal null} if {@literal pipeline} is present.
-	 * @param let can be {@literal null} if {@literal localField} and {@literal foreignField} are present.
-	 * @param as must not be {@literal null}.
-	 * @since 4.1
-	 */
-	public LookupOperation(String from, @Nullable Field localField, @Nullable Field foreignField, @Nullable Let let,
-			@Nullable AggregationPipeline pipeline, Field as) {
 
 		Assert.notNull(from, "From must not be null");
-		if (pipeline == null) {
-			Assert.notNull(localField, "LocalField must not be null");
-			Assert.notNull(foreignField, "ForeignField must not be null");
-		} else if (localField == null && foreignField == null) {
-			Assert.notNull(pipeline, "Pipeline must not be null");
-		}
+		Assert.notNull(localField, "LocalField must not be null");
+		Assert.notNull(foreignField, "ForeignField must not be null");
 		Assert.notNull(as, "As must not be null");
 
 		this.from = from;
 		this.localField = localField;
 		this.foreignField = foreignField;
 		this.as = new ExposedField(as, true);
-		this.let = let;
-		this.pipeline = pipeline;
 	}
 
 	@Override
@@ -125,20 +70,9 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 
 		Document lookupObject = new Document();
 
-		lookupObject.append("from", from);
-		if (localField != null) {
-			lookupObject.append("localField", localField.getTarget());
-		}
-		if (foreignField != null) {
-			lookupObject.append("foreignField", foreignField.getTarget());
-		}
-		if (let != null) {
-			lookupObject.append("let", let.toDocument(context).get("$let", Document.class).get("vars"));
-		}
-		if (pipeline != null) {
-			lookupObject.append("pipeline", pipeline.toDocuments(context));
-		}
-
+		lookupObject.append("from", from.getTarget());
+		lookupObject.append("localField", localField.getTarget());
+		lookupObject.append("foreignField", foreignField.getTarget());
 		lookupObject.append("as", as.getTarget());
 
 		return new Document(getOperator(), lookupObject);
@@ -167,7 +101,7 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 		LocalFieldBuilder from(String name);
 	}
 
-	public static interface LocalFieldBuilder extends PipelineBuilder {
+	public static interface LocalFieldBuilder {
 
 		/**
 		 * @param name the field from the documents input to the {@code $lookup} stage, must not be {@literal null} or
@@ -186,67 +120,7 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 		AsBuilder foreignField(String name);
 	}
 
-	/**
-	 * @since 4.1
-	 * @author Christoph Strobl
-	 */
-	public interface LetBuilder {
-
-		/**
-		 * Specifies {@link Let#getVariableNames() variables) that can be used in the
-		 * {@link PipelineBuilder#pipeline(AggregationOperation...) pipeline stages}.
-		 *
-		 * @param let must not be {@literal null}.
-		 * @return never {@literal null}.
-		 * @see PipelineBuilder
-		 */
-		PipelineBuilder let(Let let);
-
-		/**
-		 * Specifies {@link Let#getVariableNames() variables) that can be used in the
-		 * {@link PipelineBuilder#pipeline(AggregationOperation...) pipeline stages}.
-		 *
-		 * @param variables must not be {@literal null}.
-		 * @return never {@literal null}.
-		 * @see PipelineBuilder
-		 */
-		default PipelineBuilder let(ExpressionVariable... variables) {
-			return let(Let.just(variables));
-		}
-	}
-
-	/**
-	 * @since 4.1
-	 * @author Christoph Strobl
-	 */
-	public interface PipelineBuilder extends LetBuilder {
-
-		/**
-		 * Specifies the {@link AggregationPipeline pipeline} that determines the resulting documents.
-		 *
-		 * @param pipeline must not be {@literal null}.
-		 * @return never {@literal null}.
-		 */
-		AsBuilder pipeline(AggregationPipeline pipeline);
-
-		/**
-		 * Specifies the {@link AggregationPipeline#getOperations() stages} that determine the resulting documents.
-		 *
-		 * @param stages must not be {@literal null} can be empty.
-		 * @return never {@literal null}.
-		 */
-		default AsBuilder pipeline(AggregationOperation... stages) {
-			return pipeline(AggregationPipeline.of(stages));
-		}
-
-		/**
-		 * @param name the name of the new array field to add to the input documents, must not be {@literal null} or empty.
-		 * @return new instance of {@link LookupOperation}.
-		 */
-		LookupOperation as(String name);
-	}
-
-	public static interface AsBuilder extends PipelineBuilder {
+	public static interface AsBuilder {
 
 		/**
 		 * @param name the name of the new array field to add to the input documents, must not be {@literal null} or empty.
@@ -264,12 +138,10 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 	public static final class LookupOperationBuilder
 			implements FromBuilder, LocalFieldBuilder, ForeignFieldBuilder, AsBuilder {
 
-		private @Nullable String from;
+		private @Nullable Field from;
 		private @Nullable Field localField;
 		private @Nullable Field foreignField;
 		private @Nullable ExposedField as;
-		private @Nullable Let let;
-		private @Nullable AggregationPipeline pipeline;
 
 		/**
 		 * Creates new builder for {@link LookupOperation}.
@@ -284,10 +156,18 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 		public LocalFieldBuilder from(String name) {
 
 			Assert.hasText(name, "'From' must not be null or empty");
-			from = name;
+			from = Fields.field(name);
 			return this;
 		}
 
+		@Override
+		public LookupOperation as(String name) {
+
+			Assert.hasText(name, "'As' must not be null or empty");
+			as = new ExposedField(Fields.field(name), true);
+			return new LookupOperation(from, localField, foreignField, as);
+		}
+
 		@Override
 		public AsBuilder foreignField(String name) {
 
@@ -303,29 +183,5 @@ public class LookupOperation implements FieldsExposingAggregationOperation, Inhe
 			localField = Fields.field(name);
 			return this;
 		}
-
-		@Override
-		public PipelineBuilder let(Let let) {
-
-			Assert.notNull(let, "Let must not be null");
-			this.let = let;
-			return this;
-		}
-
-		@Override
-		public AsBuilder pipeline(AggregationPipeline pipeline) {
-
-			Assert.notNull(pipeline, "Pipeline must not be null");
-			this.pipeline = pipeline;
-			return this;
-		}
-
-		@Override
-		public LookupOperation as(String name) {
-
-			Assert.hasText(name, "'As' must not be null or empty");
-			as = new ExposedField(Fields.field(name), true);
-			return new LookupOperation(from, localField, foreignField, let, pipeline, as);
-		}
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/VariableOperators.java

@@ -16,6 +16,7 @@
 package org.springframework.data.mongodb.core.aggregation;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -223,41 +224,28 @@ public class VariableOperators {
 	public static class Let implements AggregationExpression {
 
 		private final List<ExpressionVariable> vars;
-
-		@Nullable //
 		private final AggregationExpression expression;
 
-		private Let(List<ExpressionVariable> vars, @Nullable AggregationExpression expression) {
+		private Let(List<ExpressionVariable> vars, AggregationExpression expression) {
 
 			this.vars = vars;
 			this.expression = expression;
 		}
 
-		/**
-		 * Create a new {@link Let} holding just the given {@literal variables}.
-		 *
-		 * @param variables must not be {@literal null}.
-		 * @return new instance of {@link Let}.
-		 * @since 4.1
-		 */
-		public static Let just(ExpressionVariable... variables) {
-			return new Let(List.of(variables), null);
-		}
-
 		/**
 		 * Start creating new {@link Let} by defining the variables for {@code $vars}.
 		 *
 		 * @param variables must not be {@literal null}.
 		 * @return
 		 */
-		public static LetBuilder define(Collection<ExpressionVariable> variables) {
+		public static LetBuilder define(final Collection<ExpressionVariable> variables) {
 
 			Assert.notNull(variables, "Variables must not be null");
 
 			return new LetBuilder() {
 
 				@Override
-				public Let andApply(AggregationExpression expression) {
+				public Let andApply(final AggregationExpression expression) {
 
 					Assert.notNull(expression, "Expression must not be null");
 					return new Let(new ArrayList<ExpressionVariable>(variables), expression);
@@ -271,10 +259,19 @@ public class VariableOperators {
 		 * @param variables must not be {@literal null}.
 		 * @return
 		 */
-		public static LetBuilder define(ExpressionVariable... variables) {
+		public static LetBuilder define(final ExpressionVariable... variables) {
 
 			Assert.notNull(variables, "Variables must not be null");
-			return define(List.of(variables));
+
+			return new LetBuilder() {
+
+				@Override
+				public Let andApply(final AggregationExpression expression) {
+
+					Assert.notNull(expression, "Expression must not be null");
+					return new Let(Arrays.asList(variables), expression);
+				}
+			};
 		}
 
 		public interface LetBuilder {
@@ -286,11 +283,10 @@ public class VariableOperators {
 			 * @return
 			 */
 			Let andApply(AggregationExpression expression);
-
 		}
 
 		@Override
-		public Document toDocument(AggregationOperationContext context) {
+		public Document toDocument(final AggregationOperationContext context) {
 			return toLet(ExposedFields.synthetic(Fields.fields(getVariableNames())), context);
 		}
 
@@ -316,22 +312,16 @@ public class VariableOperators {
 			}
 
 			letExpression.put("vars", mappedVars);
-			if (expression != null) {
-				letExpression.put("in", getMappedIn(operationContext));
-			}
+			letExpression.put("in", getMappedIn(operationContext));
 
 			return new Document("$let", letExpression);
 		}
 
 		private Document getMappedVariable(ExpressionVariable var, AggregationOperationContext context) {
 
-			if (var.expression instanceof AggregationExpression expression) {
-				return new Document(var.variableName, expression.toDocument(context));
-			}
-			if (var.expression instanceof Field field) {
-				return new Document(var.variableName, context.getReference(field).toString());
-			}
-			return new Document(var.variableName, var.expression);
+			return new Document(var.variableName,
+					var.expression instanceof AggregationExpression ? ((AggregationExpression) var.expression).toDocument(context)
+							: var.expression);
 		}
 
 		private Object getMappedIn(AggregationOperationContext context) {
@@ -383,10 +373,6 @@ public class VariableOperators {
 				return new ExpressionVariable(variableName, expression);
 			}
 
-			public ExpressionVariable forField(String fieldRef) {
-				return new ExpressionVariable(variableName, Fields.field(fieldRef));
-			}
-
 			/**
 			 * Create a new {@link ExpressionVariable} with current name and given {@literal expressionObject}.
 			 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java

@@ -868,9 +868,9 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 					dbObjectAccessor.put(prop, null);
 				}
 			} else if (!conversions.isSimpleType(value.getClass())) {
-				writePropertyInternal(value, dbObjectAccessor, prop);
+				writePropertyInternal(value, dbObjectAccessor, prop, accessor);
 			} else {
-				writeSimpleInternal(value, bson, prop);
+				writeSimpleInternal(value, bson, prop, accessor);
 			}
 		}
 	}
@@ -887,11 +887,11 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			return;
 		}
 
-		writePropertyInternal(value, dbObjectAccessor, inverseProp);
+		writePropertyInternal(value, dbObjectAccessor, inverseProp, accessor);
 	}
 
 	@SuppressWarnings({ "unchecked" })
-	protected void writePropertyInternal(@Nullable Object obj, DocumentAccessor accessor, MongoPersistentProperty prop) {
+	protected void writePropertyInternal(@Nullable Object obj, DocumentAccessor accessor, MongoPersistentProperty prop, PersistentPropertyAccessor<?> persistentPropertyAccessor) {
 
 		if (obj == null) {
 			return;
@@ -902,7 +902,13 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 
 		if (conversions.hasValueConverter(prop)) {
 			accessor.put(prop, conversions.getPropertyValueConversions().getValueConverter(prop).write(obj,
-					new MongoConversionContext(prop, this)));
+					new MongoConversionContext(new PropertyValueProvider<MongoPersistentProperty>() {
+						@Nullable
+						@Override
+						public <T> T getPropertyValue(MongoPersistentProperty property) {
+							return (T) persistentPropertyAccessor.getProperty(property);
+						}
+					}, prop, this)));
 			return;
 		}
 
@@ -1234,12 +1240,18 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		BsonUtils.addToMap(bson, key, getPotentiallyConvertedSimpleWrite(value, Object.class));
 	}
 
-	private void writeSimpleInternal(@Nullable Object value, Bson bson, MongoPersistentProperty property) {
+	private void writeSimpleInternal(@Nullable Object value, Bson bson, MongoPersistentProperty property, PersistentPropertyAccessor<?> persistentPropertyAccessor) {
 		DocumentAccessor accessor = new DocumentAccessor(bson);
 
 		if (conversions.hasValueConverter(property)) {
 			accessor.put(property, conversions.getPropertyValueConversions().getValueConverter(property).write(value,
-					new MongoConversionContext(property, this)));
+					new MongoConversionContext(new PropertyValueProvider<MongoPersistentProperty>() {
+						@Nullable
+						@Override
+						public <T> T getPropertyValue(MongoPersistentProperty property) {
+							return (T) persistentPropertyAccessor.getProperty(property);
+						}
+					}, property, this)));
 			return;
 		}
 
@@ -1892,7 +1904,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			CustomConversions conversions = context.getCustomConversions();
 			if (conversions.hasValueConverter(property)) {
 				return (T) conversions.getPropertyValueConversions().getValueConverter(property).read(value,
-						new MongoConversionContext(property, context.getSourceConverter()));
+						new MongoConversionContext(this, property, context.getSourceConverter()));
 			}
 
 			ConversionContext contextToUse = context.forProperty(property);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MongoConversionContext.java

@@ -17,6 +17,8 @@ package org.springframework.data.mongodb.core.convert;
 
 import org.bson.conversions.Bson;
 import org.springframework.data.convert.ValueConversionContext;
+import org.springframework.data.mapping.PersistentPropertyAccessor;
+import org.springframework.data.mapping.model.PropertyValueProvider;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.lang.Nullable;
@@ -29,11 +31,13 @@ import org.springframework.lang.Nullable;
  */
 public class MongoConversionContext implements ValueConversionContext<MongoPersistentProperty> {
 
+	private final PropertyValueProvider accessor; // TODO: generics
 	private final MongoPersistentProperty persistentProperty;
 	private final MongoConverter mongoConverter;
 
-	public MongoConversionContext(MongoPersistentProperty persistentProperty, MongoConverter mongoConverter) {
+	public MongoConversionContext(PropertyValueProvider<?> accessor, MongoPersistentProperty persistentProperty, MongoConverter mongoConverter) {
 
+		this.accessor = accessor;
 		this.persistentProperty = persistentProperty;
 		this.mongoConverter = mongoConverter;
 	}
@@ -43,6 +47,10 @@ public class MongoConversionContext implements ValueConversionContext<MongoPersi
 		return persistentProperty;
 	}
 
+	public Object getValue(String propertyPath) {
+		return accessor.getPropertyValue(persistentProperty.getOwner().getRequiredPersistentProperty(propertyPath));
+	}
+
 	@Override
 	public <T> T write(@Nullable Object value, TypeInformation<T> target) {
 		return (T) mongoConverter.convertToMongoType(value, target);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/QueryMapper.java

@@ -437,7 +437,7 @@ public class QueryMapper {
 				&& converter.getCustomConversions().hasValueConverter(documentField.getProperty())) {
 			return converter.getCustomConversions().getPropertyValueConversions()
 					.getValueConverter(documentField.getProperty())
-					.write(value, new MongoConversionContext(documentField.getProperty(), converter));
+					.write(value, new MongoConversionContext(null, documentField.getProperty(), converter));
 		}
 
 		if (documentField.isIdField() && !documentField.isAssociation()) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/NearQuery.java

@@ -24,16 +24,11 @@ import org.springframework.data.geo.Distance;
 import org.springframework.data.geo.Metric;
 import org.springframework.data.geo.Metrics;
 import org.springframework.data.geo.Point;
-import org.springframework.data.mongodb.core.ReadConcernAware;
-import org.springframework.data.mongodb.core.ReadPreferenceAware;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
-import com.mongodb.ReadConcern;
-import com.mongodb.ReadPreference;
-
 /**
  * Builder class to build near-queries. <br />
  * MongoDB {@code $geoNear} operator allows usage of a {@literal GeoJSON Point} or legacy coordinate pair. Though
@@ -176,7 +171,7 @@ import com.mongodb.ReadPreference;
  * @author Christoph Strobl
  * @author Mark Paluch
  */
-public final class NearQuery implements ReadConcernAware, ReadPreferenceAware {
+public final class NearQuery {
 
 	private final Point point;
 	private @Nullable Query query;
@@ -186,8 +181,6 @@ public final class NearQuery implements ReadConcernAware, ReadPreferenceAware {
 	private boolean spherical;
 	private @Nullable Long limit;
 	private @Nullable Long skip;
-	private @Nullable ReadConcern readConcern;
-	private @Nullable ReadPreference readPreference;
 
 	/**
 	 * Creates a new {@link NearQuery}.
@@ -562,74 +555,6 @@ public final class NearQuery implements ReadConcernAware, ReadPreferenceAware {
 		return query != null ? query.getCollation().orElse(null) : null;
 	}
 
-	/**
-	 * Configures the query to use the given {@link ReadConcern} unless the underlying {@link #query(Query)}
-	 * {@link Query#hasReadConcern() specifies} another one.
-	 *
-	 * @param readConcern must not be {@literal null}.
-	 * @return this.
-	 * @since 4.1
-	 */
-	public NearQuery withReadConcern(ReadConcern readConcern) {
-
-		Assert.notNull(readConcern, "ReadConcern must not be null");
-		this.readConcern = readConcern;
-		return this;
-	}
-
-	/**
-	 * Configures the query to use the given {@link ReadPreference} unless the underlying {@link #query(Query)}
-	 * {@link Query#hasReadPreference() specifies} another one.
-	 *
-	 * @param readPreference must not be {@literal null}.
-	 * @return this.
-	 * @since 4.1
-	 */
-	public NearQuery withReadPreference(ReadPreference readPreference) {
-
-		Assert.notNull(readPreference, "ReadPreference must not be null");
-		this.readPreference = readPreference;
-		return this;
-	}
-
-	/**
-	 * Get the {@link ReadConcern} to use. Will return the underlying {@link #query(Query) queries}
-	 * {@link Query#getReadConcern() ReadConcern} if present or the one defined on the {@link NearQuery#readConcern}
-	 * itself.
-	 * 
-	 * @return can be {@literal null} if none set.
-	 * @since 4.1
-	 * @see ReadConcernAware
-	 */
-	@Nullable
-	@Override
-	public ReadConcern getReadConcern() {
-
-		if (query != null && query.hasReadConcern()) {
-			return query.getReadConcern();
-		}
-		return readConcern;
-	}
-
-	/**
-	 * Get the {@link ReadPreference} to use. Will return the underlying {@link #query(Query) queries}
-	 * {@link Query#getReadPreference() ReadPreference} if present or the one defined on the
-	 * {@link NearQuery#readPreference} itself.
-	 *
-	 * @return can be {@literal null} if none set.
-	 * @since 4.1
-	 * @see ReadPreferenceAware
-	 */
-	@Nullable
-	@Override
-	public ReadPreference getReadPreference() {
-
-		if (query != null && query.hasReadPreference()) {
-			return query.getReadPreference();
-		}
-		return readPreference;
-	}
-
 	/**
 	 * Returns the {@link Document} built by the {@link NearQuery}.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Query.java

@@ -34,16 +34,10 @@ import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Order;
 import org.springframework.data.mongodb.InvalidMongoDbApiUsageException;
-import org.springframework.data.mongodb.core.ReadConcernAware;
-import org.springframework.data.mongodb.core.ReadPreferenceAware;
-import org.springframework.data.mongodb.core.query.Meta.CursorOption;
 import org.springframework.data.mongodb.util.BsonUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
-import com.mongodb.ReadConcern;
-import com.mongodb.ReadPreference;
-
 /**
  * MongoDB Query object representing criteria, projection, sorting and query hints.
  *
@@ -54,7 +48,7 @@ import com.mongodb.ReadPreference;
  * @author Mark Paluch
  * @author Anton Barkan
  */
-public class Query implements ReadConcernAware, ReadPreferenceAware {
+public class Query {
 
 	private static final String RESTRICTED_TYPES_KEY = "_$RESTRICTED_TYPES";
 
@@ -64,9 +58,6 @@ public class Query implements ReadConcernAware, ReadPreferenceAware {
 	private Sort sort = Sort.unsorted();
 	private long skip;
 	private int limit;
-	private @Nullable ReadConcern readConcern;
-	private @Nullable ReadPreference readPreference;
-
 	private @Nullable String hint;
 
 	private Meta meta = new Meta();
@@ -169,59 +160,6 @@ public class Query implements ReadConcernAware, ReadPreferenceAware {
 		return this;
 	}
 
-	/**
-	 * Configures the query to use the given {@link ReadConcern} when being executed.
-	 *
-	 * @param readConcern must not be {@literal null}.
-	 * @return this.
-	 * @since 3.1
-	 */
-	public Query withReadConcern(ReadConcern readConcern) {
-
-		Assert.notNull(readConcern, "ReadConcern must not be null");
-		this.readConcern = readConcern;
-		return this;
-	}
-
-	/**
-	 * Configures the query to use the given {@link ReadPreference} when being executed.
-	 *
-	 * @param readPreference must not be {@literal null}.
-	 * @return this.
-	 * @since 4.1
-	 */
-	public Query withReadPreference(ReadPreference readPreference) {
-
-		Assert.notNull(readPreference, "ReadPreference must not be null");
-		this.readPreference = readPreference;
-		return this;
-	}
-
-	@Override
-	public boolean hasReadConcern() {
-		return this.readConcern != null;
-	}
-
-	@Override
-	public ReadConcern getReadConcern() {
-		return this.readConcern;
-	}
-
-	@Override
-	public boolean hasReadPreference() {
-		return this.readPreference != null || getMeta().getFlags().contains(CursorOption.SECONDARY_READS);
-	}
-
-	@Override
-	public ReadPreference getReadPreference() {
-
-		if (readPreference == null) {
-			return getMeta().getFlags().contains(CursorOption.SECONDARY_READS) ? ReadPreference.primaryPreferred() : null;
-		}
-
-		return this.readPreference;
-	}
-
 	/**
 	 * Configures the query to use the given {@link Document hint} when being executed.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/QueryUtils.java

@@ -64,7 +64,6 @@ class QueryUtils {
 			combinedSort.putAll((Document) invocation.proceed());
 			return combinedSort;
 		});
-		factory.setInterfaces(new Class[0]);
 
 		return (Query) factory.getProxy(query.getClass().getClassLoader());
 	}
@@ -114,7 +113,7 @@ class QueryUtils {
 		if(parameters.isEmpty()) {
 			return -1;
 		}
-
+		
 		int i = 0;
 		for(Class<?> parameterType : parameters) {
 			if(ClassUtils.isAssignable(type, parameterType)) {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/MongoTemplateUnitTests.java

@@ -108,7 +108,6 @@ import org.springframework.util.CollectionUtils;
 import com.mongodb.MongoClientSettings;
 import com.mongodb.MongoException;
 import com.mongodb.MongoNamespace;
-import com.mongodb.ReadConcern;
 import com.mongodb.ReadPreference;
 import com.mongodb.ServerAddress;
 import com.mongodb.ServerCursor;
@@ -121,7 +120,16 @@ import com.mongodb.client.MongoClient;
 import com.mongodb.client.MongoCollection;
 import com.mongodb.client.MongoCursor;
 import com.mongodb.client.MongoDatabase;
-import com.mongodb.client.model.*;
+import com.mongodb.client.model.CountOptions;
+import com.mongodb.client.model.CreateCollectionOptions;
+import com.mongodb.client.model.DeleteOptions;
+import com.mongodb.client.model.FindOneAndDeleteOptions;
+import com.mongodb.client.model.FindOneAndReplaceOptions;
+import com.mongodb.client.model.FindOneAndUpdateOptions;
+import com.mongodb.client.model.MapReduceAction;
+import com.mongodb.client.model.ReplaceOptions;
+import com.mongodb.client.model.TimeSeriesGranularity;
+import com.mongodb.client.model.UpdateOptions;
 import com.mongodb.client.result.DeleteResult;
 import com.mongodb.client.result.UpdateResult;
 
@@ -174,7 +182,6 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 		when(collection.estimatedDocumentCount(any())).thenReturn(1L);
 		when(collection.getNamespace()).thenReturn(new MongoNamespace("db.mock-collection"));
 		when(collection.aggregate(any(List.class), any())).thenReturn(aggregateIterable);
-		when(collection.withReadConcern(any())).thenReturn(collection);
 		when(collection.withReadPreference(any())).thenReturn(collection);
 		when(collection.replaceOne(any(), any(), any(ReplaceOptions.class))).thenReturn(updateResult);
 		when(collection.withWriteConcern(any())).thenReturn(collectionWithWriteConcern);
@@ -471,34 +478,6 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 		verify(collection, never()).withReadPreference(any());
 	}
 
-	@Test // GH-4277
-	void aggregateShouldHonorOptionsReadConcernWhenSet() {
-
-		AggregationOptions options = AggregationOptions.builder().readConcern(ReadConcern.SNAPSHOT).build();
-		template.aggregate(newAggregation(Aggregation.unwind("foo")).withOptions(options), "collection-1", Wrapper.class);
-
-		verify(collection).withReadConcern(ReadConcern.SNAPSHOT);
-	}
-
-	@Test // GH-4277
-	void aggregateShouldHonorOptionsReadPreferenceWhenSet() {
-
-		AggregationOptions options = AggregationOptions.builder().readPreference(ReadPreference.secondary()).build();
-		template.aggregate(newAggregation(Aggregation.unwind("foo")).withOptions(options), "collection-1", Wrapper.class);
-
-		verify(collection).withReadPreference(ReadPreference.secondary());
-	}
-
-	@Test // GH-4277
-	void aggregateStreamShouldHonorOptionsReadPreferenceWhenSet() {
-
-		AggregationOptions options = AggregationOptions.builder().readPreference(ReadPreference.secondary()).build();
-		template.aggregateStream(newAggregation(Aggregation.unwind("foo")).withOptions(options), "collection-1",
-				Wrapper.class);
-
-		verify(collection).withReadPreference(ReadPreference.secondary());
-	}
-
 	@Test // DATAMONGO-2153
 	void aggregateShouldHonorOptionsComment() {
 
@@ -579,28 +558,6 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 		verify(collection).withReadPreference(eq(ReadPreference.secondary()));
 	}
 
-	@Test // GH-4277
-	void geoNearShouldHonorReadPreferenceFromQuery() {
-
-		NearQuery query = NearQuery.near(new Point(1, 1));
-		query.withReadPreference(ReadPreference.secondary());
-
-		template.geoNear(query, Wrapper.class);
-
-		verify(collection).withReadPreference(eq(ReadPreference.secondary()));
-	}
-
-	@Test // GH-4277
-	void geoNearShouldHonorReadConcernFromQuery() {
-
-		NearQuery query = NearQuery.near(new Point(1, 1));
-		query.withReadConcern(ReadConcern.SNAPSHOT);
-
-		template.geoNear(query, Wrapper.class);
-
-		verify(collection).withReadConcern(eq(ReadConcern.SNAPSHOT));
-	}
-
 	@Test // DATAMONGO-1166, DATAMONGO-2264
 	void geoNearShouldIgnoreReadPreferenceWhenNotSet() {
 
@@ -845,24 +802,6 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 		verify(findIterable).batchSize(1234);
 	}
 
-	@Test // GH-4277
-	void findShouldUseReadConcernWhenPresent() {
-
-		template.find(new BasicQuery("{'foo' : 'bar'}").withReadConcern(ReadConcern.SNAPSHOT),
-				AutogenerateableId.class);
-
-		verify(collection).withReadConcern(ReadConcern.SNAPSHOT);
-	}
-
-	@Test // GH-4277
-	void findShouldUseReadPreferenceWhenPresent() {
-
-		template.find(new BasicQuery("{'foo' : 'bar'}").withReadPreference(ReadPreference.secondary()),
-				AutogenerateableId.class);
-
-		verify(collection).withReadPreference(ReadPreference.secondary());
-	}
-
 	@Test // DATAMONGO-1518
 	void executeQueryShouldUseCollationWhenPresent() {
 
@@ -1109,8 +1048,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void appliesFieldsWhenInterfaceProjectionIsClosedAndQueryDoesNotDefineFields() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document(), Person.class,
-				PersonProjection.class,
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonProjection.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(new Document("firstname", 1)));
@@ -1119,8 +1057,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void doesNotApplyFieldsWhenInterfaceProjectionIsClosedAndQueryDefinesFields() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document("bar", 1), Person.class,
-				PersonProjection.class,
+		template.doFind("star-wars", new Document(), new Document("bar", 1), Person.class, PersonProjection.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(new Document("bar", 1)));
@@ -1129,8 +1066,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void doesNotApplyFieldsWhenInterfaceProjectionIsOpen() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document(), Person.class,
-				PersonSpELProjection.class,
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonSpELProjection.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(BsonUtils.EMPTY_DOCUMENT));
@@ -1139,8 +1075,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733, DATAMONGO-2041
 	void appliesFieldsToDtoProjection() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document(), Person.class,
-				Jedi.class,
+		template.doFind("star-wars", new Document(), new Document(), Person.class, Jedi.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(new Document("firstname", 1)));
@@ -1149,8 +1084,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void doesNotApplyFieldsToDtoProjectionWhenQueryDefinesFields() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document("bar", 1), Person.class,
-				Jedi.class,
+		template.doFind("star-wars", new Document(), new Document("bar", 1), Person.class, Jedi.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(new Document("bar", 1)));
@@ -1159,8 +1093,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void doesNotApplyFieldsWhenTargetIsNotAProjection() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document(), Person.class,
-				Person.class,
+		template.doFind("star-wars", new Document(), new Document(), Person.class, Person.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(BsonUtils.EMPTY_DOCUMENT));
@@ -1169,8 +1102,7 @@ public class MongoTemplateUnitTests extends MongoOperationsUnitTests {
 	@Test // DATAMONGO-1733
 	void doesNotApplyFieldsWhenTargetExtendsDomainType() {
 
-		template.doFind(CollectionPreparer.identity(), "star-wars", new Document(), new Document(), Person.class,
-				PersonExtended.class,
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonExtended.class,
 				CursorPreparer.NO_OP_PREPARER);
 
 		verify(findIterable).projection(eq(BsonUtils.EMPTY_DOCUMENT));

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateUnitTests.java

@@ -23,6 +23,8 @@ import static org.springframework.data.mongodb.test.util.Assertions.assertThat;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
+import org.springframework.data.mongodb.core.MongoTemplateUnitTests.Wrapper;
+import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -54,12 +56,12 @@ import org.mockito.junit.jupiter.MockitoSettings;
 import org.mockito.quality.Strictness;
 import org.reactivestreams.Publisher;
 import org.reactivestreams.Subscriber;
+
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.data.annotation.Id;
-import org.springframework.data.geo.Point;
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.callback.ReactiveEntityCallbacks;
 import org.springframework.data.mapping.context.MappingContext;
@@ -98,7 +100,6 @@ import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.CollectionUtils;
 
 import com.mongodb.MongoClientSettings;
-import com.mongodb.ReadConcern;
 import com.mongodb.ReadPreference;
 import com.mongodb.client.model.CountOptions;
 import com.mongodb.client.model.CreateCollectionOptions;
@@ -167,7 +168,6 @@ public class ReactiveMongoTemplateUnitTests {
 		when(db.runCommand(any(), any(Class.class))).thenReturn(runCommandPublisher);
 		when(db.createCollection(any(), any(CreateCollectionOptions.class))).thenReturn(runCommandPublisher);
 		when(collection.withReadPreference(any())).thenReturn(collection);
-		when(collection.withReadConcern(any())).thenReturn(collection);
 		when(collection.find(any(Class.class))).thenReturn(findPublisher);
 		when(collection.find(any(Document.class), any(Class.class))).thenReturn(findPublisher);
 		when(collection.aggregate(anyList())).thenReturn(aggregatePublisher);
@@ -385,33 +385,11 @@ public class ReactiveMongoTemplateUnitTests {
 		verify(aggregatePublisher).collation(eq(com.mongodb.client.model.Collation.builder().locale("fr").build()));
 	}
 
-	@Test // GH-4277
-	void geoNearShouldHonorReadPreferenceFromQuery() {
-
-		NearQuery query = NearQuery.near(new Point(1, 1));
-		query.withReadPreference(ReadPreference.secondary());
-
-		template.geoNear(query, Wrapper.class).subscribe();
-
-		verify(collection).withReadPreference(eq(ReadPreference.secondary()));
-	}
-
-	@Test // GH-4277
-	void geoNearShouldHonorReadConcernFromQuery() {
-
-		NearQuery query = NearQuery.near(new Point(1, 1));
-		query.withReadConcern(ReadConcern.SNAPSHOT);
-
-		template.geoNear(query, Wrapper.class).subscribe();
-
-		verify(collection).withReadConcern(eq(ReadConcern.SNAPSHOT));
-	}
-
 	@Test // DATAMONGO-1719
 	void appliesFieldsWhenInterfaceProjectionIsClosedAndQueryDoesNotDefineFields() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document(), Person.class,
-				PersonProjection.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonProjection.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher).projection(eq(new Document("firstname", 1)));
 	}
@@ -419,8 +397,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719
 	void doesNotApplyFieldsWhenInterfaceProjectionIsClosedAndQueryDefinesFields() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document("bar", 1), Person.class,
-				PersonProjection.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document("bar", 1), Person.class, PersonProjection.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher).projection(eq(new Document("bar", 1)));
 	}
@@ -428,8 +406,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719
 	void doesNotApplyFieldsWhenInterfaceProjectionIsOpen() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document(), Person.class,
-				PersonSpELProjection.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonSpELProjection.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher, never()).projection(any());
 	}
@@ -437,8 +415,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719, DATAMONGO-2041
 	void appliesFieldsToDtoProjection() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document(), Person.class,
-				Jedi.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document(), Person.class, Jedi.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher).projection(eq(new Document("firstname", 1)));
 	}
@@ -446,8 +424,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719
 	void doesNotApplyFieldsToDtoProjectionWhenQueryDefinesFields() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document("bar", 1), Person.class,
-				Jedi.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document("bar", 1), Person.class, Jedi.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher).projection(eq(new Document("bar", 1)));
 	}
@@ -455,8 +433,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719
 	void doesNotApplyFieldsWhenTargetIsNotAProjection() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document(), Person.class,
-				Person.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document(), Person.class, Person.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher, never()).projection(any());
 	}
@@ -464,8 +442,8 @@ public class ReactiveMongoTemplateUnitTests {
 	@Test // DATAMONGO-1719
 	void doesNotApplyFieldsWhenTargetExtendsDomainType() {
 
-		template.doFind("star-wars", CollectionPreparer.identity(), new Document(), new Document(), Person.class,
-				PersonExtended.class, FindPublisherPreparer.NO_OP_PREPARER).subscribe();
+		template.doFind("star-wars", new Document(), new Document(), Person.class, PersonExtended.class,
+				FindPublisherPreparer.NO_OP_PREPARER).subscribe();
 
 		verify(findPublisher, never()).projection(any());
 	}
@@ -654,26 +632,6 @@ public class ReactiveMongoTemplateUnitTests {
 		verify(aggregatePublisher).collation(eq(com.mongodb.client.model.Collation.builder().locale("de_AT").build()));
 	}
 
-	@Test // GH-4277
-	void aggreateShouldUseReadConcern() {
-
-		AggregationOptions options = AggregationOptions.builder().readConcern(ReadConcern.SNAPSHOT).build();
-		template.aggregate(newAggregation(Sith.class, project("id")).withOptions(options), AutogenerateableId.class,
-				Document.class).subscribe();
-
-		verify(collection).withReadConcern(ReadConcern.SNAPSHOT);
-	}
-
-	@Test // GH-4286
-	void aggreateShouldUseReadReadPreference() {
-
-		AggregationOptions options = AggregationOptions.builder().readPreference(ReadPreference.primaryPreferred()).build();
-		template.aggregate(newAggregation(Sith.class, project("id")).withOptions(options), AutogenerateableId.class,
-				Document.class).subscribe();
-
-		verify(collection).withReadPreference(ReadPreference.primaryPreferred());
-	}
-
 	@Test // DATAMONGO-1854
 	void aggreateShouldUseCollationFromOptionsEvenIfDefaultCollationIsPresent() {
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/AggregationTests.java

@@ -43,6 +43,7 @@ import java.util.stream.Stream;
 
 import org.assertj.core.data.Offset;
 import org.bson.Document;
+import org.bson.types.ObjectId;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -60,7 +61,6 @@ import org.springframework.data.mongodb.core.TestEntities;
 import org.springframework.data.mongodb.core.Venue;
 import org.springframework.data.mongodb.core.aggregation.AggregationTests.CarDescriptor.Entry;
 import org.springframework.data.mongodb.core.aggregation.BucketAutoOperation.Granularities;
-import org.springframework.data.mongodb.core.aggregation.VariableOperators.Let;
 import org.springframework.data.mongodb.core.aggregation.VariableOperators.Let.ExpressionVariable;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
 import org.springframework.data.mongodb.core.index.GeoSpatialIndexType;
@@ -90,7 +90,6 @@ import com.mongodb.client.MongoCollection;
  * @author Maninder Singh
  * @author Sergey Shcherbakov
  * @author Minsu Kim
- * @author Sangyong Choi
  */
 @ExtendWith(MongoTemplateExtension.class)
 public class AggregationTests {
@@ -500,7 +499,7 @@ public class AggregationTests {
 		/*
 		 //complex mongodb aggregation framework example from
 		 https://docs.mongodb.org/manual/tutorial/aggregation-examples/#largest-and-smallest-cities-by-state
-		
+
 		 db.zipcodes.aggregate(
 			 	{
 				   $group: {
@@ -1519,47 +1518,8 @@ public class AggregationTests {
 		assertThat(firstItem).containsEntry("linkedPerson.[0].firstname", "u1");
 	}
 
-	@Test // GH-3322
-	@EnableIfMongoServerVersion(isGreaterThanEqual = "5.0")
-	void shouldLookupPeopleCorrectlyWithPipeline() {
-		createUsersWithReferencedPersons();
-
-		TypedAggregation<User> agg = newAggregation(User.class, //
-				lookup().from("person").localField("_id").foreignField("firstname").pipeline(match(where("firstname").is("u1"))).as("linkedPerson"), //
-				sort(ASC, "id"));
-
-		AggregationResults<Document> results = mongoTemplate.aggregate(agg, User.class, Document.class);
-
-		List<Document> mappedResults = results.getMappedResults();
-
-		Document firstItem = mappedResults.get(0);
-
-		assertThat(firstItem).containsEntry("_id", "u1");
-		assertThat(firstItem).containsEntry("linkedPerson.[0].firstname", "u1");
-	}
-
-	@Test // GH-3322
-	@EnableIfMongoServerVersion(isGreaterThanEqual = "5.0")
-	void shouldLookupPeopleCorrectlyWithPipelineAndLet() {
-		createUsersWithReferencedPersons();
-
-		TypedAggregation<User> agg = newAggregation(User.class, //
-				lookup().from("person").localField("_id").foreignField("firstname").let(Let.ExpressionVariable.newVariable("the_id").forField("_id")).pipeline(
-						match(ctx -> new Document("$expr", new Document("$eq", List.of("$$the_id", "u1"))))).as("linkedPerson"),
-				sort(ASC, "id"));
-
-		AggregationResults<Document> results = mongoTemplate.aggregate(agg, User.class, Document.class);
-
-		List<Document> mappedResults = results.getMappedResults();
-
-		Document firstItem = mappedResults.get(0);
-
-		assertThat(firstItem).containsEntry("_id", "u1");
-		assertThat(firstItem).containsEntry("linkedPerson.[0].firstname", "u1");
-	}
-
 	@Test // DATAMONGO-1326
-	void shouldGroupByAndLookupPeopleCorrectly() {
+	void shouldGroupByAndLookupPeopleCorectly() {
 
 		createUsersWithReferencedPersons();
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/LookupOperationUnitTests.java

@@ -16,16 +16,11 @@
 package org.springframework.data.mongodb.core.aggregation;
 
 import static org.assertj.core.api.Assertions.*;
-import static org.springframework.data.mongodb.core.aggregation.Aggregation.*;
-import static org.springframework.data.mongodb.core.aggregation.VariableOperators.Let.ExpressionVariable.*;
-import static org.springframework.data.mongodb.test.util.Assertions.assertThat;
-
-import java.util.List;
 
 import org.bson.Document;
 import org.junit.jupiter.api.Test;
+
 import org.springframework.data.mongodb.core.DocumentTestUtils;
-import org.springframework.data.mongodb.core.query.Criteria;
 
 /**
  * Unit tests for {@link LookupOperation}.
@@ -67,7 +62,7 @@ public class LookupOperationUnitTests {
 
 		Document lookupClause = extractDocumentFromLookupOperation(lookupOperation);
 
-		org.assertj.core.api.Assertions.assertThat(lookupClause).containsEntry("from", "a") //
+		assertThat(lookupClause).containsEntry("from", "a") //
 				.containsEntry("localField", "b") //
 				.containsEntry("foreignField", "c") //
 				.containsEntry("as", "d");
@@ -119,7 +114,7 @@ public class LookupOperationUnitTests {
 
 		Document lookupClause = extractDocumentFromLookupOperation(lookupOperation);
 
-		org.assertj.core.api.Assertions.assertThat(lookupClause).containsEntry("from", "a") //
+		assertThat(lookupClause).containsEntry("from", "a") //
 				.containsEntry("localField", "b") //
 				.containsEntry("foreignField", "c") //
 				.containsEntry("as", "d");
@@ -134,86 +129,4 @@ public class LookupOperationUnitTests {
 		assertThat(lookupOperation.getFields().exposesSingleFieldOnly()).isTrue();
 		assertThat(lookupOperation.getFields().getField("d")).isNotNull();
 	}
-
-	@Test // GH-3322
-	void buildsLookupWithLetAndPipeline() {
-
-		LookupOperation lookupOperation = LookupOperation.newLookup().from("warehouses")
-				.let(newVariable("order_item").forField("item"), newVariable("order_qty").forField("ordered"))
-				.pipeline(match(ctx -> new Document("$expr",
-						new Document("$and", List.of(Document.parse("{ $eq: [ \"$stock_item\",  \"$$order_item\" ] }"),
-								Document.parse("{ $gte: [ \"$instock\", \"$$order_qty\" ] }"))))))
-				.as("stockdata");
-
-		assertThat(lookupOperation.toDocument(Aggregation.DEFAULT_CONTEXT)).isEqualTo("""
-				{ $lookup: {
-					from: "warehouses",
-					let: { order_item: "$item", order_qty: "$ordered" },
-					pipeline: [
-						{ $match:
-							{ $expr:
-								{ $and:
-									[
-										{ $eq: [ "$stock_item",  "$$order_item" ] },
-										{ $gte: [ "$instock", "$$order_qty" ] }
-									]
-								}
-							}
-						}
-					],
-					as: "stockdata"
-				}}
-				""");
-	}
-
-	@Test // GH-3322
-	void buildsLookupWithJustPipeline() {
-
-		LookupOperation lookupOperation = LookupOperation.newLookup().from("holidays") //
-				.pipeline( //
-						match(Criteria.where("year").is(2018)), //
-						project().andExclude("_id").and(ctx -> new Document("name", "$name").append("date", "$date")).as("date"), //
-						Aggregation.replaceRoot("date") //
-				).as("holidays");
-
-		assertThat(lookupOperation.toDocument(Aggregation.DEFAULT_CONTEXT)).isEqualTo("""
-				{ $lookup:
-					{
-						from: "holidays",
-						pipeline: [
-							{ $match: { year: 2018 } },
-							{ $project: { _id: 0, date: { name: "$name", date: "$date" } } },
-							{ $replaceRoot: { newRoot: "$date" } }
-						],
-						as: "holidays"
-					}
-				}}
-				""");
-	}
-
-	@Test // GH-3322
-	void buildsLookupWithLocalAndForeignFieldAsWellAsLetAndPipeline() {
-
-		LookupOperation lookupOperation = Aggregation.lookup().from("restaurants") //
-				.localField("restaurant_name")
-				.foreignField("name")
-				.let(newVariable("orders_drink").forField("drink")) //
-				.pipeline(match(ctx -> new Document("$expr", new Document("$in", List.of("$$orders_drink", "$beverages")))))
-				.as("matches");
-
-		assertThat(lookupOperation.toDocument(Aggregation.DEFAULT_CONTEXT)).isEqualTo("""
-				{ $lookup: {
-					from: "restaurants",
-					localField: "restaurant_name",
-					foreignField: "name",
-					let: { orders_drink: "$drink" },
-					pipeline: [{
-						$match: {
-							$expr: { $in: [ "$$orders_drink", "$beverages" ] }
-						}
-					}],
-					as: "matches"
-				}}
-				""");
-	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java

@@ -2613,7 +2613,7 @@ class MappingMongoConverterUnitTests {
 		doReturn(Person.class).when(persistentProperty).getType();
 		doReturn(Person.class).when(persistentProperty).getRawType();
 
-		converter.writePropertyInternal(sourceValue, accessor, persistentProperty);
+		converter.writePropertyInternal(sourceValue, accessor, persistentProperty, null);
 
 		assertThat(accessor.getDocument())
 				.isEqualTo(new org.bson.Document("pName", new org.bson.Document("_id", id.toString())));

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/messaging/ChangeStreamTests.java

@@ -21,6 +21,9 @@ import static org.springframework.data.mongodb.core.messaging.SubscriptionUtils.
 import static org.springframework.data.mongodb.core.query.Criteria.*;
 import static org.springframework.data.mongodb.core.query.Query.*;
 
+import com.mongodb.client.model.ChangeStreamPreAndPostImagesOptions;
+import com.mongodb.client.model.CreateCollectionOptions;
+import com.mongodb.client.model.changestream.FullDocumentBeforeChange;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
@@ -39,10 +42,8 @@ import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
-import org.junitpioneer.jupiter.RepeatFailedTest;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.ChangeStreamOptions;
 import org.springframework.data.mongodb.core.CollectionOptions;
@@ -61,7 +62,7 @@ import org.springframework.data.mongodb.test.util.Template;
 
 import com.mongodb.client.model.changestream.ChangeStreamDocument;
 import com.mongodb.client.model.changestream.FullDocument;
-import com.mongodb.client.model.changestream.FullDocumentBeforeChange;
+import org.junitpioneer.jupiter.RepeatFailedTest;
 
 /**
  * Integration test for subscribing to a {@link com.mongodb.operation.ChangeStreamBatchCursor} inside the
@@ -701,7 +702,7 @@ class ChangeStreamTests {
 	}
 
 	@Test // GH-4187
-	@Disabled("Flakey test failing occasionally due to timing issues")
+	@EnableIfMongoServerVersion(isLessThan = "6.0")
 	void readsFullDocumentBeforeChangeWhenOptionDeclaredRequiredAndMongoVersionIsLessThan6() throws InterruptedException {
 
 		CollectingMessageListener<ChangeStreamDocument<Document>, User> messageListener = new CollectingMessageListener<>();

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/query/NearQueryUnitTests.java

@@ -29,10 +29,6 @@ import org.springframework.data.geo.Metrics;
 import org.springframework.data.geo.Point;
 import org.springframework.data.mongodb.core.DocumentTestUtils;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
-import org.springframework.test.util.ReflectionTestUtils;
-
-import com.mongodb.ReadConcern;
-import com.mongodb.ReadPreference;
 
 /**
  * Unit tests for {@link NearQuery}.
@@ -233,58 +229,4 @@ public class NearQueryUnitTests {
 
 		assertThat(query.toDocument()).containsEntry("maxDistance", 1000D).containsEntry("distanceMultiplier", 0.00062137D);
 	}
-
-	@Test // GH-4277
-	void fetchesReadPreferenceFromUnderlyingQueryObject() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0))
-				.query(new Query().withReadPreference(ReadPreference.nearest()));
-
-		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.nearest());
-	}
-
-	@Test // GH-4277
-	void fetchesReadConcernFromUnderlyingQueryObject() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).query(new Query().withReadConcern(ReadConcern.SNAPSHOT));
-
-		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.SNAPSHOT);
-	}
-
-	@Test // GH-4277
-	void usesReadPreferenceFromNearQueryIfUnderlyingQueryDoesNotDefineAny() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadPreference(ReadPreference.nearest())
-				.query(new Query());
-
-		assertThat(((Query) ReflectionTestUtils.getField(nearQuery, "query")).getReadPreference()).isNull();
-		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.nearest());
-	}
-
-	@Test // GH-4277
-	void usesReadConcernFromNearQueryIfUnderlyingQueryDoesNotDefineAny() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadConcern(ReadConcern.SNAPSHOT).query(new Query());
-
-		assertThat(((Query) ReflectionTestUtils.getField(nearQuery, "query")).getReadConcern()).isNull();
-		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.SNAPSHOT);
-	}
-
-	@Test // GH-4277
-	void readPreferenceFromUnderlyingQueryOverridesNearQueryOne() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadPreference(ReadPreference.nearest())
-				.query(new Query().withReadPreference(ReadPreference.primary()));
-
-		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.primary());
-	}
-
-	@Test // GH-4277
-	void readConcernFromUnderlyingQueryOverridesNearQueryOne() {
-
-		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadConcern(ReadConcern.SNAPSHOT)
-				.query(new Query().withReadConcern(ReadConcern.MAJORITY));
-
-		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.MAJORITY);
-	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/query/QueryTests.java

@@ -342,10 +342,7 @@ class QueryTests {
 		source.limit(10);
 		source.setSortObject(new Document("_id", 1));
 
-		ProxyFactory proxyFactory = new ProxyFactory(source);
-		proxyFactory.setInterfaces(new Class[0]);
-
-		Query target = Query.of((Query) proxyFactory.getProxy());
+		Query target = Query.of((Query) new ProxyFactory(source).getProxy());
 
 		compareQueries(target, source);
 	}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/fle/FLETests.java

@@ -0,0 +1,528 @@
+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.fle;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.springframework.data.mongodb.core.EncryptionAlgorithms.*;
+import static org.springframework.data.mongodb.core.query.Criteria.*;
+
+import lombok.Data;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.security.SecureRandom;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import org.bson.BsonArray;
+import org.bson.BsonBinary;
+import org.bson.BsonDocument;
+import org.bson.BsonValue;
+import org.bson.Document;
+import org.bson.types.Binary;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.CollectionFactory;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.dao.PermissionDeniedDataAccessException;
+import org.springframework.data.convert.PropertyValueConverterFactory;
+import org.springframework.data.convert.ValueConverter;
+import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.convert.MongoConversionContext;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions.MongoConverterConfigurationAdapter;
+import org.springframework.data.mongodb.core.convert.MongoValueConverter;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.data.mongodb.fle.FLETests.Config;
+import org.springframework.data.mongodb.util.BsonUtils;
+import org.springframework.data.util.Lazy;
+import org.springframework.lang.Nullable;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
+
+import com.mongodb.ClientEncryptionSettings;
+import com.mongodb.ConnectionString;
+import com.mongodb.MongoClientSettings;
+import com.mongodb.MongoNamespace;
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.model.Filters;
+import com.mongodb.client.model.IndexOptions;
+import com.mongodb.client.model.Indexes;
+import com.mongodb.client.model.vault.DataKeyOptions;
+import com.mongodb.client.model.vault.EncryptOptions;
+import com.mongodb.client.result.DeleteResult;
+import com.mongodb.client.vault.ClientEncryption;
+import com.mongodb.client.vault.ClientEncryptions;
+
+/**
+ * @author Christoph Strobl
+ */
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = Config.class)
+public class FLETests {
+
+	@Autowired MongoTemplate template;
+
+	@Test
+	void manualEnAndDecryption() {
+
+		Person person = new Person();
+		person.id = "id-1";
+		person.name = "p1-name";
+		person.ssn = "mySecretSSN"; // determinisitc encryption (queryable)
+		person.wallet = "myEvenMoreSecretStuff"; // random encryption (non queryable)
+
+		// nested full document encryption
+		person.address = new Address();
+		person.address.city = "NYC";
+		person.address.street = "4th Ave.";
+
+		person.encryptedZip = new AddressWithEncryptedZip();
+		person.encryptedZip.city = "Boston";
+		person.encryptedZip.street = "central square";
+		person.encryptedZip.zip = "1234567890";
+
+		person.listOfString = Arrays.asList("spring", "data", "mongodb");
+
+		Address partOfList = new Address();
+		partOfList.city = "SFO";
+		partOfList.street = "---";
+		person.listOfComplex = Collections.singletonList(partOfList);
+
+		template.save(person);
+
+		System.out.println("source: " + person);
+
+		Document savedDocument = template.execute(Person.class, collection -> {
+			return collection.find(new Document()).first();
+		});
+
+		// ssn should look like "ssn": {"$binary": {"base64": "...
+		System.out.println("saved: " + savedDocument.toJson());
+		assertThat(savedDocument.get("ssn")).isInstanceOf(Binary.class);
+		assertThat(savedDocument.get("wallet")).isInstanceOf(Binary.class);
+		assertThat(savedDocument.get("encryptedZip")).isInstanceOf(Document.class);
+		assertThat(savedDocument.get("encryptedZip", Document.class).get("zip")).isInstanceOf(Binary.class);
+		assertThat(savedDocument.get("address")).isInstanceOf(Binary.class);
+		assertThat(savedDocument.get("listOfString")).isInstanceOf(Binary.class);
+		assertThat(savedDocument.get("listOfComplex")).isInstanceOf(Binary.class);
+
+		// count should be 1 using a deterministic algorithm
+		long queryCount = template.query(Person.class).matching(where("ssn").is(person.ssn)).count();
+		System.out.println("query(count): " + queryCount);
+		assertThat(queryCount).isOne();
+
+		Person bySsn = template.query(Person.class).matching(where("ssn").is(person.ssn)).firstValue();
+		System.out.println("queryable: " + bySsn);
+		assertThat(bySsn).isEqualTo(person);
+
+		Person byWallet = template.query(Person.class).matching(where("wallet").is(person.wallet)).firstValue();
+		System.out.println("not-queryable: " + byWallet);
+		assertThat(byWallet).isNull();
+	}
+
+	@Test
+	void theUpdateStuff() {
+
+		Person person = new Person();
+		person.id = "id-1";
+		person.name = "p1-name";
+
+		template.save(person);
+
+		Document savedDocument = template.execute(Person.class, collection -> {
+			return collection.find(new Document()).first();
+		});
+		System.out.println("saved: " + savedDocument.toJson());
+
+		template.update(Person.class).matching(where("id").is(person.id)).apply(Update.update("ssn", "secret-value")).first();
+
+		savedDocument = template.execute(Person.class, collection -> {
+			return collection.find(new Document()).first();
+		});
+		System.out.println("updated: " + savedDocument.toJson());
+		assertThat(savedDocument.get("ssn")).isInstanceOf(Binary.class);
+
+	}
+
+	@Test
+	void altKeyDetection(@Autowired ClientEncryption clientEncryption) throws InterruptedException {
+
+		BsonBinary user1key = clientEncryption.createDataKey("local",
+				new DataKeyOptions().keyAltNames(Collections.singletonList("user-1")));
+
+		BsonBinary user2key = clientEncryption.createDataKey("local",
+				new DataKeyOptions().keyAltNames(Collections.singletonList("user-2")));
+
+		Person p1 = new Person();
+		p1.id = "id-1";
+		p1.name = "user-1";
+		p1.ssn = "ssn";
+		p1.viaAltKeyNameField = "value-1";
+
+		Person p2 = new Person();
+		p2.id = "id-2";
+		p2.name = "user-2";
+		p2.viaAltKeyNameField = "value-1";
+
+		Person p3 = new Person();
+		p3.id = "id-3";
+		p3.name = "user-1";
+		p3.viaAltKeyNameField = "value-1";
+
+		template.save(p1);
+		template.save(p2);
+		template.save(p3);
+
+		template.execute(Person.class, collection -> {
+			collection.find(new Document()).forEach(it -> System.out.println(it.toJson()));
+			return null;
+		});
+
+		// System.out.println(template.query(Person.class).matching(where("id").is(p1.id)).firstValue());
+		// System.out.println(template.query(Person.class).matching(where("id").is(p2.id)).firstValue());
+
+		DeleteResult deleteResult = clientEncryption.deleteKey(user2key);
+		clientEncryption.getKeys().forEach(System.out::println);
+		System.out.println("deleteResult: " + deleteResult);
+
+		System.out.println("---- waiting for cache timeout ----");
+		TimeUnit.SECONDS.sleep(90);
+
+		assertThat(template.query(Person.class).matching(where("id").is(p1.id)).firstValue()).isEqualTo(p1);
+
+		assertThatExceptionOfType(PermissionDeniedDataAccessException.class)
+				.isThrownBy(() -> template.query(Person.class).matching(where("id").is(p2.id)).firstValue());
+	}
+
+	@Configuration
+	static class Config extends AbstractMongoClientConfiguration {
+
+		@Autowired ApplicationContext applicationContext;
+
+		@Override
+		protected String getDatabaseName() {
+			return "fle-test";
+		}
+
+		@Bean
+		public MongoClient mongoClient() {
+			return super.mongoClient();
+		}
+
+		@Override
+		protected void configureConverters(MongoConverterConfigurationAdapter converterConfigurationAdapter) {
+
+			converterConfigurationAdapter
+					.registerPropertyValueConverterFactory(PropertyValueConverterFactory.beanFactoryAware(applicationContext));
+		}
+
+		@Bean
+		EncryptingConverter encryptingConverter(ClientEncryption clientEncryption) {
+			return new EncryptingConverter(clientEncryption);
+		}
+
+		@Bean
+		ClientEncryption clientEncryption(MongoClient mongoClient) {
+
+			final byte[] localMasterKey = new byte[96];
+			new SecureRandom().nextBytes(localMasterKey);
+			Map<String, Map<String, Object>> kmsProviders = new HashMap<String, Map<String, Object>>() {
+				{
+					put("local", new HashMap<String, Object>() {
+						{
+							put("key", localMasterKey);
+						}
+					});
+				}
+			};
+
+			MongoNamespace keyVaultNamespace = new MongoNamespace("encryption.testKeyVault");
+			MongoCollection<Document> keyVaultCollection = mongoClient.getDatabase(keyVaultNamespace.getDatabaseName())
+					.getCollection(keyVaultNamespace.getCollectionName());
+			keyVaultCollection.drop();
+			// Ensure that two data keys cannot share the same keyAltName.
+			keyVaultCollection.createIndex(Indexes.ascending("keyAltNames"),
+					new IndexOptions().unique(true).partialFilterExpression(Filters.exists("keyAltNames")));
+
+			MongoCollection<Document> collection = mongoClient.getDatabase(getDatabaseName()).getCollection("test");
+			collection.drop(); // Clear old data
+
+			// Create the ClientEncryption instance
+			ClientEncryptionSettings clientEncryptionSettings = ClientEncryptionSettings.builder()
+					.keyVaultMongoClientSettings(
+							MongoClientSettings.builder().applyConnectionString(new ConnectionString("mongodb://localhost")).build())
+					.keyVaultNamespace(keyVaultNamespace.getFullName()).kmsProviders(kmsProviders).build();
+			ClientEncryption clientEncryption = ClientEncryptions.create(clientEncryptionSettings);
+			return clientEncryption;
+		}
+	}
+
+	@Data
+	@org.springframework.data.mongodb.core.mapping.Document("test")
+	static class Person {
+
+		String id;
+		String name;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Deterministic) //
+		String ssn;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random, altKeyName = "mySuperSecretKey") //
+		String wallet;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random) // full document must be random
+		Address address;
+
+		AddressWithEncryptedZip encryptedZip;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random) // lists must be random
+		List<String> listOfString;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random) // lists must be random
+		List<Address> listOfComplex;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random, altKeyName = "/name") //
+		String viaAltKeyNameField;
+	}
+
+	@Data
+	static class Address {
+		String city;
+		String street;
+	}
+
+	@Getter
+	@Setter
+	static class AddressWithEncryptedZip extends Address {
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Random) String zip;
+
+		@Override
+		public String toString() {
+			return "AddressWithEncryptedZip{" + "zip='" + zip + '\'' + ", city='" + getCity() + '\'' + ", street='"
+					+ getStreet() + '\'' + '}';
+		}
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(ElementType.FIELD)
+	@Encrypted
+	@ValueConverter(EncryptingConverter.class)
+	@interface EncryptedField {
+
+		@AliasFor(annotation = Encrypted.class, value = "algorithm")
+		String algorithm() default "";
+
+		String altKeyName() default "";
+	}
+
+	static class EncryptingConverter implements MongoValueConverter<Object, Object> {
+
+		private ClientEncryption clientEncryption;
+		private BsonBinary dataKeyId; // should be provided from outside.
+
+		public EncryptingConverter(ClientEncryption clientEncryption) {
+
+			this.clientEncryption = clientEncryption;
+			this.dataKeyId = clientEncryption.createDataKey("local",
+					new DataKeyOptions().keyAltNames(Collections.singletonList("mySuperSecretKey")));
+		}
+
+		@Nullable
+		@Override
+		public Object read(Object value, MongoConversionContext context) {
+
+			ManualEncryptionContext encryptionContext = buildEncryptionContext(context);
+			Object decrypted = encryptionContext.decrypt(value, clientEncryption);
+			return decrypted instanceof BsonValue ? BsonUtils.toJavaType((BsonValue) decrypted) : decrypted;
+		}
+
+		@Nullable
+		@Override
+		public BsonBinary write(Object value, MongoConversionContext context) {
+
+			ManualEncryptionContext encryptionContext = buildEncryptionContext(context);
+			return encryptionContext.encrypt(value, clientEncryption);
+		}
+
+		ManualEncryptionContext buildEncryptionContext(MongoConversionContext context) {
+			return new ManualEncryptionContext(context, this.dataKeyId);
+		}
+	}
+
+	static class ManualEncryptionContext {
+
+		MongoConversionContext context;
+		MongoPersistentProperty persistentProperty;
+		BsonBinary dataKeyId;
+		Lazy<Encrypted> encryption;
+
+		public ManualEncryptionContext(MongoConversionContext context, BsonBinary dataKeyId) {
+			this.context = context;
+			this.persistentProperty = context.getProperty();
+			this.dataKeyId = dataKeyId;
+			this.encryption = Lazy.of(() -> persistentProperty.findAnnotation(Encrypted.class));
+		}
+
+		BsonBinary encrypt(Object value, ClientEncryption clientEncryption) {
+
+			// TODO: check - encryption.get().keyId()
+
+			EncryptOptions encryptOptions = new EncryptOptions(encryption.get().algorithm());
+
+			EncryptedField annotation = persistentProperty.findAnnotation(EncryptedField.class);
+			if (annotation != null && !annotation.altKeyName().isBlank()) {
+				if (annotation.altKeyName().startsWith("/")) {
+					String fieldName = annotation.altKeyName().replace("/", "");
+					Object altKeyNameValue = context.getValue(fieldName);
+					encryptOptions = encryptOptions.keyAltName(altKeyNameValue.toString());
+				} else {
+					encryptOptions = encryptOptions.keyAltName(annotation.altKeyName());
+				}
+			} else {
+				encryptOptions = encryptOptions.keyId(this.dataKeyId);
+			}
+
+			System.out.println(
+					"encrypting with: " + (StringUtils.hasText(encryptOptions.getKeyAltName()) ? encryptOptions.getKeyAltName()
+							: encryptOptions.getKeyId()));
+
+			if (!persistentProperty.isEntity()) {
+
+				if (persistentProperty.isCollectionLike()) {
+					return clientEncryption.encrypt(collectionLikeToBsonValue(value), encryptOptions);
+				}
+				return clientEncryption.encrypt(BsonUtils.simpleToBsonValue(value), encryptOptions);
+			}
+			if (persistentProperty.isCollectionLike()) {
+				return clientEncryption.encrypt(collectionLikeToBsonValue(value), encryptOptions);
+			}
+
+			Object write = context.write(value);
+			if (write instanceof Document doc) {
+				return clientEncryption.encrypt(doc.toBsonDocument(), encryptOptions);
+			}
+			return clientEncryption.encrypt(BsonUtils.simpleToBsonValue(write), encryptOptions);
+		}
+
+		public BsonValue collectionLikeToBsonValue(Object value) {
+
+			if (persistentProperty.isCollectionLike()) {
+
+				BsonArray bsonArray = new BsonArray();
+				if (!persistentProperty.isEntity()) {
+					if (value instanceof Collection values) {
+						values.forEach(it -> bsonArray.add(BsonUtils.simpleToBsonValue(it)));
+					} else if (ObjectUtils.isArray(value)) {
+						for (Object o : ObjectUtils.toObjectArray(value)) {
+							bsonArray.add(BsonUtils.simpleToBsonValue(o));
+						}
+					}
+					return bsonArray;
+				} else {
+					if (value instanceof Collection values) {
+						values.forEach(it -> {
+							Document write = (Document) context.write(it, persistentProperty.getTypeInformation());
+							bsonArray.add(write.toBsonDocument());
+						});
+					} else if (ObjectUtils.isArray(value)) {
+						for (Object o : ObjectUtils.toObjectArray(value)) {
+							Document write = (Document) context.write(0, persistentProperty.getTypeInformation());
+							bsonArray.add(write.toBsonDocument());
+						}
+					}
+					return bsonArray;
+				}
+			}
+
+			if (!persistentProperty.isEntity()) {
+				if (persistentProperty.isCollectionLike()) {
+
+					if (persistentProperty.isEntity()) {
+
+					}
+				}
+			}
+
+			return null;
+		}
+
+		public Object decrypt(Object value, ClientEncryption clientEncryption) {
+
+			// this was a hack to avoid the 60 sec timeout of the key cache
+			// ClientEncryptionSettings settings = (ClientEncryptionSettings) new DirectFieldAccessor(clientEncryption)
+			// .getPropertyValue("options");
+			// clientEncryption = ClientEncryptions.create(settings);
+
+			Object result = value;
+			if (value instanceof Binary binary) {
+				result = clientEncryption.decrypt(new BsonBinary(binary.getType(), binary.getData()));
+			}
+			if (value instanceof BsonBinary binary) {
+				result = clientEncryption.decrypt(binary);
+			}
+
+			// in case the driver has auto decryption (aka .bypassAutoEncryption(true)) active
+			// https://github.com/mongodb/mongo-java-driver/blob/master/driver-sync/src/examples/tour/ClientSideEncryptionExplicitEncryptionOnlyTour.java
+			if (value == result) {
+				return result;
+			}
+
+			if (persistentProperty.isCollectionLike() && result instanceof Iterable<?> iterable) {
+				if (!persistentProperty.isEntity()) {
+					Collection<Object> collection = CollectionFactory.createCollection(persistentProperty.getType(), 10);
+					iterable.forEach(it -> collection.add(BsonUtils.toJavaType((BsonValue) it)));
+					return collection;
+				} else {
+					Collection<Object> collection = CollectionFactory.createCollection(persistentProperty.getType(), 10);
+					iterable.forEach(it -> {
+						collection.add(context.read(BsonUtils.toJavaType((BsonValue) it), persistentProperty.getActualType()));
+					});
+					return collection;
+				}
+			}
+
+			if (!persistentProperty.isEntity() && result instanceof BsonValue bsonValue) {
+				return BsonUtils.toJavaType(bsonValue);
+			}
+
+			if (persistentProperty.isEntity() && result instanceof BsonDocument bsonDocument) {
+				return context.read(BsonUtils.toJavaType(bsonDocument), persistentProperty.getTypeInformation());
+			}
+
+			return result;
+		}
+	}
+}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/fle/ReactiveFLETests.java

@@ -0,0 +1,440 @@
+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.fle;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.springframework.data.mongodb.core.EncryptionAlgorithms.*;
+import static org.springframework.data.mongodb.core.query.Criteria.*;
+
+import lombok.Data;
+import org.springframework.data.mongodb.fle.FLETests.Person;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.security.SecureRandom;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.concurrent.ExecutionException;
+import java.util.function.Supplier;
+
+import org.bson.BsonArray;
+import org.bson.BsonBinary;
+import org.bson.BsonDocument;
+import org.bson.BsonValue;
+import org.bson.Document;
+import org.bson.types.Binary;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.reactivestreams.Publisher;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.CollectionFactory;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.data.convert.PropertyValueConverterFactory;
+import org.springframework.data.convert.ValueConverter;
+import org.springframework.data.mongodb.config.AbstractReactiveMongoConfiguration;
+import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
+import org.springframework.data.mongodb.core.convert.MongoConversionContext;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions.MongoConverterConfigurationAdapter;
+import org.springframework.data.mongodb.core.convert.MongoValueConverter;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.fle.FLETests.Config;
+import org.springframework.data.mongodb.util.BsonUtils;
+import org.springframework.data.util.Lazy;
+import org.springframework.lang.Nullable;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
+
+import com.mongodb.ClientEncryptionSettings;
+import com.mongodb.ConnectionString;
+import com.mongodb.MongoClientSettings;
+import com.mongodb.MongoNamespace;
+import com.mongodb.client.model.Filters;
+import com.mongodb.client.model.IndexOptions;
+import com.mongodb.client.model.Indexes;
+import com.mongodb.client.model.vault.DataKeyOptions;
+import com.mongodb.client.model.vault.EncryptOptions;
+import com.mongodb.reactivestreams.client.MongoClient;
+import com.mongodb.reactivestreams.client.MongoCollection;
+import com.mongodb.reactivestreams.client.vault.ClientEncryption;
+import com.mongodb.reactivestreams.client.vault.ClientEncryptions;
+
+/**
+ * @author Christoph Strobl
+ * @since 2022/11
+ */
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(classes = ReactiveFLETests.Config.class)
+public class ReactiveFLETests {
+
+	ClientEncryption encryption;
+
+	@Test
+	void xxx() {
+
+		Supplier<String> valueSupplier = new Supplier<String>() {
+			@Override
+			public String get() {
+				System.out.println("invoked");
+				return "v1";
+			}
+		};
+
+		Document source = new Document("name", "value").append("mono", Mono.fromSupplier(() -> "from mono"))
+				.append("nested", new Document("n1", Mono.fromSupplier(() -> "from nested mono")));
+
+		resolveValues(Mono.just(source)) //
+				.as(StepVerifier::create).consumeNextWith(resolved -> {
+					assertThat(resolved).isEqualTo(Document
+							.parse("{\"name\": \"value\", \"mono\": \"from mono\", \"nested\" : { \"n1\" : \"from nested mono\"}}"));
+				}).verifyComplete();
+	}
+
+	private Mono<Document> resolveValues(Mono<Document> document) {
+		return document.flatMap(source -> {
+			for (Entry<String, Object> entry : source.entrySet()) {
+				if (entry.getValue()instanceof Mono<?> valueMono) {
+					return valueMono.flatMap(value -> {
+						source.put(entry.getKey(), value);
+						return resolveValues(Mono.just(source));
+					});
+				}
+				if (entry.getValue()instanceof Document nested) {
+					return resolveValues(Mono.just(nested)).map(it -> {
+						source.put(entry.getKey(), it);
+						return source;
+					});
+				}
+			}
+			return Mono.just(source);
+		});
+	}
+
+	@Autowired ReactiveMongoTemplate template;
+
+	@Test
+	void manualEnAndDecryption() {
+
+		Person person = new Person();
+		person.id = "id-1";
+		person.name = "p1-name";
+		person.ssn = "mySecretSSN";
+
+		template.save(person).block();
+
+		System.out.println("source: " + person);
+
+		Flux<Document> result = template.execute(FLETests.Person.class, collection -> {
+			return Mono.from(collection.find(new Document()).first());
+		});
+
+		System.out.println("encrypted: " + result.blockFirst().toJson());
+
+		Person id = template.query(Person.class).matching(where("id").is(person.id)).first().block();
+		System.out.println("decrypted: " + id);
+	}
+
+	@Data
+	@org.springframework.data.mongodb.core.mapping.Document("test")
+	static class Person {
+
+		String id;
+		String name;
+
+		@EncryptedField(algorithm = AEAD_AES_256_CBC_HMAC_SHA_512_Deterministic) //
+		String ssn;
+	}
+
+	@Configuration
+	static class Config extends AbstractReactiveMongoConfiguration {
+
+		@Autowired ApplicationContext applicationContext;
+
+		@Override
+		protected String getDatabaseName() {
+			return "fle-test";
+		}
+
+		@Override
+		protected void configureConverters(MongoConverterConfigurationAdapter converterConfigurationAdapter) {
+
+			converterConfigurationAdapter
+					.registerPropertyValueConverterFactory(PropertyValueConverterFactory.beanFactoryAware(applicationContext));
+		}
+
+		@Bean
+		@Override
+		public MongoClient reactiveMongoClient() {
+			return super.reactiveMongoClient();
+		}
+
+		@Bean
+		ReactiveEncryptingConverter encryptingConverter(ClientEncryption clientEncryption) {
+			return new ReactiveEncryptingConverter(clientEncryption);
+		}
+
+		@Bean
+		ClientEncryption clientEncryption(MongoClient mongoClient) {
+
+			final byte[] localMasterKey = new byte[96];
+			new SecureRandom().nextBytes(localMasterKey);
+			Map<String, Map<String, Object>> kmsProviders = new HashMap<String, Map<String, Object>>() {
+				{
+					put("local", new HashMap<String, Object>() {
+						{
+							put("key", localMasterKey);
+						}
+					});
+				}
+			};
+
+			MongoNamespace keyVaultNamespace = new MongoNamespace("encryption.testKeyVault");
+			MongoCollection<Document> keyVaultCollection = mongoClient.getDatabase(keyVaultNamespace.getDatabaseName())
+					.getCollection(keyVaultNamespace.getCollectionName());
+			Mono.from(keyVaultCollection.drop()).block();
+			// Ensure that two data keys cannot share the same keyAltName.
+			keyVaultCollection.createIndex(Indexes.ascending("keyAltNames"),
+					new IndexOptions().unique(true).partialFilterExpression(Filters.exists("keyAltNames")));
+
+			MongoCollection<Document> collection = mongoClient.getDatabase(getDatabaseName()).getCollection("test");
+			Mono.from(collection.drop()).block(); // Clear old data
+
+			// Create the ClientEncryption instance
+			ClientEncryptionSettings clientEncryptionSettings = ClientEncryptionSettings.builder()
+					.keyVaultMongoClientSettings(
+							MongoClientSettings.builder().applyConnectionString(new ConnectionString("mongodb://localhost")).build())
+					.keyVaultNamespace(keyVaultNamespace.getFullName()).kmsProviders(kmsProviders).build();
+			ClientEncryption clientEncryption = ClientEncryptions.create(clientEncryptionSettings);
+			return clientEncryption;
+		}
+	}
+
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(ElementType.FIELD)
+	@Encrypted
+	@ValueConverter(ReactiveEncryptingConverter.class)
+	@interface EncryptedField {
+
+		@AliasFor(annotation = Encrypted.class, value = "algorithm")
+		String algorithm() default "";
+
+		String altKeyName() default "";
+	}
+
+	static class ReactiveEncryptingConverter implements MongoValueConverter<Object, Object> {
+
+		private ClientEncryption clientEncryption;
+		private BsonBinary dataKeyId; // should be provided from outside.
+
+		public ReactiveEncryptingConverter(ClientEncryption clientEncryption) {
+
+			this.clientEncryption = clientEncryption;
+			this.dataKeyId = Mono.from(clientEncryption.createDataKey("local",
+					new DataKeyOptions().keyAltNames(Collections.singletonList("mySuperSecretKey")))).block();
+		}
+
+		@Nullable
+		@Override
+		public Object read(Object value, MongoConversionContext context) {
+
+			ManualEncryptionContext encryptionContext = buildEncryptionContext(context);
+			Object decrypted = null;
+			try {
+				decrypted = encryptionContext.decrypt(value, clientEncryption);
+			} catch (ExecutionException e) {
+				throw new RuntimeException(e);
+			} catch (InterruptedException e) {
+				throw new RuntimeException(e);
+			}
+			return decrypted instanceof BsonValue ? BsonUtils.toJavaType((BsonValue) decrypted) : decrypted;
+		}
+
+		@Nullable
+		@Override
+		public Publisher<BsonBinary> write(Object value, MongoConversionContext context) {
+
+			ManualEncryptionContext encryptionContext = buildEncryptionContext(context);
+			return encryptionContext.encrypt(value, clientEncryption);
+		}
+
+		ManualEncryptionContext buildEncryptionContext(MongoConversionContext context) {
+			return new ManualEncryptionContext(context, this.dataKeyId);
+		}
+	}
+
+	static class ManualEncryptionContext {
+
+		MongoConversionContext context;
+		MongoPersistentProperty persistentProperty;
+		BsonBinary dataKeyId;
+		Lazy<Encrypted> encryption;
+
+		public ManualEncryptionContext(MongoConversionContext context, BsonBinary dataKeyId) {
+			this.context = context;
+			this.persistentProperty = context.getProperty();
+			this.dataKeyId = dataKeyId;
+			this.encryption = Lazy.of(() -> persistentProperty.findAnnotation(Encrypted.class));
+		}
+
+		Publisher<BsonBinary> encrypt(Object value, ClientEncryption clientEncryption) {
+
+			// TODO: check - encryption.get().keyId()
+
+			EncryptOptions encryptOptions = new EncryptOptions(encryption.get().algorithm());
+
+			EncryptedField annotation = persistentProperty.findAnnotation(EncryptedField.class);
+			if (annotation != null && !annotation.altKeyName().isBlank()) {
+				if (annotation.altKeyName().startsWith("/")) {
+					String fieldName = annotation.altKeyName().replace("/", "");
+					Object altKeyNameValue = context.getValue(fieldName);
+					encryptOptions = encryptOptions.keyAltName(altKeyNameValue.toString());
+				} else {
+					encryptOptions = encryptOptions.keyAltName(annotation.altKeyName());
+				}
+			} else {
+				encryptOptions = encryptOptions.keyId(this.dataKeyId);
+			}
+
+			System.out.println(
+					"encrypting with: " + (StringUtils.hasText(encryptOptions.getKeyAltName()) ? encryptOptions.getKeyAltName()
+							: encryptOptions.getKeyId()));
+
+			if (!persistentProperty.isEntity()) {
+
+				if (persistentProperty.isCollectionLike()) {
+					return clientEncryption.encrypt(collectionLikeToBsonValue(value), encryptOptions);
+				}
+				return clientEncryption.encrypt(BsonUtils.simpleToBsonValue(value), encryptOptions);
+			}
+			if (persistentProperty.isCollectionLike()) {
+				return clientEncryption.encrypt(collectionLikeToBsonValue(value), encryptOptions);
+			}
+
+			Object write = context.write(value);
+			if (write instanceof Document doc) {
+				return clientEncryption.encrypt(doc.toBsonDocument(), encryptOptions);
+			}
+			return clientEncryption.encrypt(BsonUtils.simpleToBsonValue(write), encryptOptions);
+		}
+
+		public BsonValue collectionLikeToBsonValue(Object value) {
+
+			if (persistentProperty.isCollectionLike()) {
+
+				BsonArray bsonArray = new BsonArray();
+				if (!persistentProperty.isEntity()) {
+					if (value instanceof Collection values) {
+						values.forEach(it -> bsonArray.add(BsonUtils.simpleToBsonValue(it)));
+					} else if (ObjectUtils.isArray(value)) {
+						for (Object o : ObjectUtils.toObjectArray(value)) {
+							bsonArray.add(BsonUtils.simpleToBsonValue(o));
+						}
+					}
+					return bsonArray;
+				} else {
+					if (value instanceof Collection values) {
+						values.forEach(it -> {
+							Document write = (Document) context.write(it, persistentProperty.getTypeInformation());
+							bsonArray.add(write.toBsonDocument());
+						});
+					} else if (ObjectUtils.isArray(value)) {
+						for (Object o : ObjectUtils.toObjectArray(value)) {
+							Document write = (Document) context.write(o, persistentProperty.getTypeInformation());
+							bsonArray.add(write.toBsonDocument());
+						}
+					}
+					return bsonArray;
+				}
+			}
+
+			if (!persistentProperty.isEntity()) {
+				if (persistentProperty.isCollectionLike()) {
+
+					if (persistentProperty.isEntity()) {
+
+					}
+				}
+			}
+
+			return null;
+		}
+
+		public Object decrypt(Object value, ClientEncryption clientEncryption) throws ExecutionException, InterruptedException {
+
+			// this was a hack to avoid the 60 sec timeout of the key cache
+			// ClientEncryptionSettings settings = (ClientEncryptionSettings) new DirectFieldAccessor(clientEncryption)
+			// .getPropertyValue("options");
+			// clientEncryption = ClientEncryptions.create(settings);
+
+			Object r = value;
+			if (value instanceof Binary binary) {
+				r = clientEncryption.decrypt(new BsonBinary(binary.getType(), binary.getData()));
+			}
+			if (value instanceof BsonBinary binary) {
+				r = clientEncryption.decrypt(binary);
+			}
+
+			// in case the driver has auto decryption (aka .bypassAutoEncryption(true)) active
+			// https://github.com/mongodb/mongo-java-driver/blob/master/driver-sync/src/examples/tour/ClientSideEncryptionExplicitEncryptionOnlyTour.java
+			if (value == r) {
+				return r;
+			}
+
+			if(r instanceof Mono mono) {
+				return mono.map(result -> {
+					if (persistentProperty.isCollectionLike() && result instanceof Iterable<?> iterable) {
+						if (!persistentProperty.isEntity()) {
+							Collection<Object> collection = CollectionFactory.createCollection(persistentProperty.getType(), 10);
+							iterable.forEach(it -> collection.add(BsonUtils.toJavaType((BsonValue) it)));
+							return collection;
+						} else {
+							Collection<Object> collection = CollectionFactory.createCollection(persistentProperty.getType(), 10);
+							iterable.forEach(it -> {
+								collection.add(context.read(BsonUtils.toJavaType((BsonValue) it), persistentProperty.getActualType()));
+							});
+							return collection;
+						}
+					}
+
+					if (!persistentProperty.isEntity() && result instanceof BsonValue bsonValue) {
+						return BsonUtils.toJavaType(bsonValue);
+					}
+
+					if (persistentProperty.isEntity() && result instanceof BsonDocument bsonDocument) {
+						return context.read(BsonUtils.toJavaType(bsonDocument), persistentProperty.getTypeInformation());
+					}
+					return result;
+				}).toFuture().get();
+			}
+
+			return r;
+		}
+	}
+
+}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/SimpleReactiveMongoRepositoryUnitTests.java

@@ -28,6 +28,7 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+
 import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.mongodb.core.ReactiveMongoOperations;
@@ -119,11 +120,7 @@ class SimpleReactiveMongoRepositoryUnitTests {
 	@Test // DATAMONGO-1854
 	void shouldAddDefaultCollationToFindOneForExampleIfPresent() {
 
-		when(entityInformation.getCollectionName()).thenReturn("testdummy");
-		doReturn(flux).when(mongoOperations).find(any(Query.class), eq(TestDummy.class), eq("testdummy"));
-		when(flux.buffer(anyInt())).thenReturn(flux);
-		when(flux.map(any())).thenReturn(flux);
-		when(flux.next()).thenReturn(mono);
+		when(mongoOperations.find(any(), any(), any())).thenReturn(flux);
 
 		Collation collation = Collation.of("en_US");
 

src/main/resources/notice.txt

@@ -1,4 +1,4 @@
-Spring Data MongoDB 4.1 M1 (2023.0.0)
+Spring Data MongoDB 4.0 GA (2022.0.0)
 Copyright (c) [2010-2019] Pivotal Software, Inc.
 
 This product is licensed to you under the Apache License, Version 2.0 (the "License").
@@ -40,6 +40,5 @@ conditions of the subcomponent's license, as noted in the LICENSE file.
 
 
 
-