diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
index 88cf6d1d1..df3afd769 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
@@ -15,7 +15,6 @@
  */
 package org.springframework.data.mongodb.core;
 
-import javax.validation.constraints.Null;
 import java.util.Collection;
 import java.util.List;
 import java.util.Set;
@@ -77,6 +76,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * converted into Spring's DAO exception hierarchy.
 	 *
 	 * @param jsonCommand a MongoDB command expressed as a JSON string.
+	 * @return a result object returned by the action.
 	 */
 	Document executeCommand(String jsonCommand);
 
@@ -84,7 +84,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Execute a MongoDB command. Any errors that result from executing this command will be converted into Spring's DAO
 	 * exception hierarchy.
 	 *
-	 * @param command a MongoDB command
+	 * @param command a MongoDB command.
+	 * @return a result object returned by the action.
 	 */
 	Document executeCommand(Document command);
 
@@ -94,7 +95,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param command a MongoDB command, must not be {@literal null}.
 	 * @param readPreference read preferences to use, can be {@literal null}.
-	 * @return
+	 * @return a result object returned by the action.
 	 * @since 1.7
 	 */
 	Document executeCommand(Document command, @Nullable ReadPreference readPreference);
@@ -103,9 +104,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Execute a MongoDB query and iterate over the query results on a per-document basis with a DocumentCallbackHandler.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @param dch the handler that will extract results, one document at a time
+	 *          specification. Must not be {@literal null}.
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @param dch the handler that will extract results, one document at a time.
 	 */
 	void executeQuery(Query query, String collectionName, DocumentCallbackHandler dch);
 
@@ -116,7 +117,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param action callback object that specifies the MongoDB actions to perform on the passed in DB instance. Must not
 	 *          be {@literal null}.
-	 * @param <T> return type
+	 * @param <T> return type.
 	 * @return a result object returned by the action or {@literal null}.
 	 */
 	@Nullable
@@ -127,9 +128,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <p/>
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
-	 * @param <T> return type
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
 	 * @param action callback object that specifies the MongoDB action. Must not be {@literal null}.
+	 * @param <T> return type.
 	 * @return a result object returned by the action or {@literal null}.
 	 */
 	@Nullable
@@ -140,10 +141,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <p/>
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
-	 * @param <T> return type
-	 * @param collectionName the name of the collection that specifies which DBCollection instance will be passed into.
-	 *          Must not be {@literal null} or empty.
+	 * @param collectionName the name of the collection that specifies which {@link MongoCollection} instance will be
+	 *          passed into. Must not be {@literal null} or empty.
 	 * @param action callback object that specifies the MongoDB action the callback action. Must not be {@literal null}.
+	 * @param <T> return type.
 	 * @return a result object returned by the action or {@literal null}.
 	 */
 	@Nullable
@@ -155,9 +156,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <p>
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link Cursor} that needs to be closed.
 	 *
-	 * @param <T> element return type
-	 * @param query must not be {@literal null}.
+	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
+	 *          specification. Must not be {@literal null}.
 	 * @param entityType must not be {@literal null}.
+	 * @param <T> element return type
 	 * @return will never be {@literal null}.
 	 * @since 1.7
 	 */
@@ -169,10 +171,11 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <p>
 	 * Returns a {@link CloseableIterator} that wraps the a Mongo DB {@link Cursor} that needs to be closed.
 	 *
-	 * @param <T> element return type
-	 * @param query must not be {@literal null}.
+	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
+	 *          specification. Must not be {@literal null}.
 	 * @param entityType must not be {@literal null}.
 	 * @param collectionName must not be {@literal null} or empty.
+	 * @param <T> element return type
 	 * @return will never be {@literal null}.
 	 * @since 1.10
 	 */
@@ -181,8 +184,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Create an uncapped collection with a name based on the provided entity class.
 	 *
-	 * @param entityClass class that determines the collection to create
-	 * @return the created collection
+	 * @param entityClass class that determines the collection to create.
+	 * @return the created collection.
 	 */
 	<T> MongoCollection<Document> createCollection(Class<T> entityClass);
 
@@ -191,15 +194,15 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param entityClass class that determines the collection to create. Must not be {@literal null}.
 	 * @param collectionOptions options to use when creating the collection.
-	 * @return the created collection
+	 * @return the created collection.
 	 */
 	<T> MongoCollection<Document> createCollection(Class<T> entityClass, @Nullable CollectionOptions collectionOptions);
 
 	/**
 	 * Create an uncapped collection with the provided name.
 	 *
-	 * @param collectionName name of the collection
-	 * @return the created collection
+	 * @param collectionName name of the collection.
+	 * @return the created collection.
 	 */
 	MongoCollection<Document> createCollection(String collectionName);
 
@@ -208,14 +211,14 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param collectionName name of the collection. Must not be {@literal null} nor empty.
 	 * @param collectionOptions options to use when creating the collection.
-	 * @return the created collection
+	 * @return the created collection.
 	 */
 	MongoCollection<Document> createCollection(String collectionName, @Nullable CollectionOptions collectionOptions);
 
 	/**
 	 * A set of collection names.
 	 *
-	 * @return list of collection names
+	 * @return list of collection names.
 	 */
 	Set<String> getCollectionNames();
 
@@ -324,13 +327,13 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Query for a list of objects of type T from the collection used by the entity class.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
-	 * @param entityClass the parametrized type of the returned list
-	 * @return the converted collection
+	 * @param entityClass the parametrized type of the returned list.
+	 * @return the converted collection.
 	 */
 	<T> List<T> findAll(Class<T> entityClass);
 
@@ -338,14 +341,14 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Query for a list of objects of type T from the specified collection.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * If your collection does not contain a homogeneous collection of types, this operation will not be an efficient way
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
 	 * @param entityClass the parametrized type of the returned list.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the converted collection
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the converted collection.
 	 */
 	<T> List<T> findAll(Class<T> entityClass, String collectionName);
 
@@ -376,7 +379,8 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param entityClass The parametrized type of the returned list
 	 * @return The results of the group operation
 	 */
-	<T> GroupByResults<T> group(@Nullable Criteria criteria, String inputCollectionName, GroupBy groupBy, Class<T> entityClass);
+	<T> GroupByResults<T> group(@Nullable Criteria criteria, String inputCollectionName, GroupBy groupBy,
+			Class<T> entityClass);
 
 	/**
 	 * Execute an aggregation operation. The raw results will be mapped to the given entity class. The name of the
@@ -587,15 +591,15 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * specified type.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned list.
-	 * @return the converted object
+	 * @return the converted object.
 	 */
 	@Nullable
 	<T> T findOne(Query query, Class<T> entityClass);
@@ -605,16 +609,16 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * type.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned list.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the converted object
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the converted object.
 	 */
 	@Nullable
 	<T> T findOne(Query query, Class<T> entityClass, String collectionName);
@@ -626,7 +630,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param collectionName name of the collection to check for objects.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	boolean exists(Query query, String collectionName);
 
@@ -635,7 +639,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param entityClass the parametrized type.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	boolean exists(Query query, Class<?> entityClass);
 
@@ -645,7 +649,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param entityClass the parametrized type. Can be {@literal null}.
 	 * @param collectionName name of the collection to check for objects.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	boolean exists(Query query, @Nullable Class<?> entityClass, String collectionName);
 
@@ -653,7 +657,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Map the results of an ad-hoc query on the collection for the entity class to a List of the specified type.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
@@ -661,7 +665,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
 	 *          specification. Must not be {@literal null}.
 	 * @param entityClass the parametrized type of the returned list. Must not be {@literal null}.
-	 * @return the List of converted objects
+	 * @return the List of converted objects.
 	 */
 	<T> List<T> find(Query query, Class<T> entityClass);
 
@@ -669,7 +673,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Map the results of an ad-hoc query on the specified collection to a List of the specified type.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
@@ -678,7 +682,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *          specification. Must not be {@literal null}.
 	 * @param entityClass the parametrized type of the returned list. Must not be {@literal null}.
 	 * @param collectionName name of the collection to retrieve the objects from. Must not be {@literal null}.
-	 * @return the List of converted objects
+	 * @return the List of converted objects.
 	 */
 	<T> List<T> find(Query query, Class<T> entityClass, String collectionName);
 
@@ -686,7 +690,6 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Returns a document with the given id mapped onto the given class. The collection the query is ran against will be
 	 * derived from the given target class as well.
 	 *
-	 * @param <T>
 	 * @param id the id of the document to return. Must not be {@literal null}.
 	 * @param entityClass the type the document shall be converted into. Must not be {@literal null}.
 	 * @return the document with the given id mapped onto the given target class.
@@ -697,30 +700,29 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Returns the document with the given id from the given collection mapped onto the given target class.
 	 *
-	 * @param id the id of the document to return
-	 * @param entityClass the type to convert the document to
-	 * @param collectionName the collection to query for the document
-	 * @param <T>
-	 * @return {@literal null} if document does not exist.
+	 * @param id the id of the document to return.
+	 * @param entityClass the type to convert the document to.
+	 * @param collectionName the collection to query for the document.
+	 * @return he converted object or {@literal null} if document does not exist.
 	 */
 	@Nullable
 	<T> T findById(Object id, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="http://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
 	 *          fields specification. Must not be {@literal null}.
 	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
-	 * @return {@literal null} if not found.
+	 * @return the converted object that was updated before it was updated or {@literal null}, if not found.
 	 */
 	@Nullable
 	<T> T findAndModify(Query query, Update update, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="http://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
@@ -728,13 +730,13 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
-	 * @return {@literal null} if not found.
+	 * @return the converted object that was updated before it was updated or {@literal null}, if not found.
 	 */
 	@Nullable
 	<T> T findAndModify(Query query, Update update, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="http://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
@@ -743,13 +745,15 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param update the {@link Update} to apply on matching documents.
 	 * @param options the {@link FindAndModifyOptions} holding additional information.
 	 * @param entityClass the parametrized type.
-	 * @return {@literal null} if not found.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndModifyOptions#isReturnNew()} this will either be the object as it was before the update or as
+	 *         it is after the update.
 	 */
 	@Nullable
 	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="http://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
@@ -759,7 +763,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
 	 * @param entityClass the parametrized type. Must not be {@literal null}.
 	 * @param collectionName the collection to query. Must not be {@literal null}.
-	 * @return {@literal null} if not found.
+	 * @return the converted object that was updated or {@literal null}, if not found. Depending on the value of
+	 *         {@link FindAndModifyOptions#isReturnNew()} this will either be the object as it was before the update or as
+	 *         it is after the update.
 	 */
 	@Nullable
 	<T> T findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
@@ -776,7 +782,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned list.
 	 * @return the converted object
 	 */
@@ -788,16 +794,16 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * type. The first document that matches the query is returned and also removed from the collection in the database.
 	 * <p/>
 	 * The object is converted from the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * The query is specified as a {@link Query} which can be created either using the {@link BasicQuery} or the more
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned list.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the converted object
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the converted object.
 	 */
 	@Nullable
 	<T> T findAndRemove(Query query, Class<T> entityClass, String collectionName);
@@ -805,9 +811,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the collection of the given entity class.
 	 *
-	 * @param query must not be {@literal null}.
-	 * @param entityClass must not be {@literal null}.
-	 * @return
+	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
+	 *          {@literal null}.
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the count of matching documents.
 	 */
 	long count(Query query, Class<?> entityClass);
 
@@ -816,9 +823,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * must solely consist of document field references as we lack type information to map potential property references
 	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query must not be {@literal null}.
+	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
-	 * @return
+	 * @return the count of matching documents.
 	 * @see #count(Query, Class, String)
 	 */
 	long count(Query query, String collectionName);
@@ -827,10 +834,11 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Returns the number of documents for the given {@link Query} by querying the given collection using the given entity
 	 * class to map the given {@link Query}.
 	 *
-	 * @param query must not be {@literal null}.
-	 * @param entityClass can be be {@literal null}.
+	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
+	 *          {@literal null}.
+	 * @param entityClass the parametrized type. Can be {@literal null}.
 	 * @param collectionName must not be {@literal null} or empty.
-	 * @return
+	 * @return the count of matching documents.
 	 */
 	long count(Query query, @Nullable Class<?> entityClass, String collectionName);
 
@@ -856,7 +864,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Insert the object into the specified collection.
 	 * <p/>
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
 	 *
@@ -868,13 +876,13 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Insert a Collection of objects into a collection in a single batch write to the database.
 	 *
-	 * @param batchToSave the list of objects to save. Must not be {@literal null}.
+	 * @param batchToSave the batch of objects to save. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
 	 */
 	void insert(Collection<? extends Object> batchToSave, Class<?> entityClass);
 
 	/**
-	 * Insert a list of objects into the specified collection in a single batch write to the database.
+	 * Insert a batch of objects into the specified collection in a single batch write to the database.
 	 *
 	 * @param batchToSave the list of objects to save. Must not be {@literal null}.
 	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
@@ -894,7 +902,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * object is not already present, that is an 'upsert'.
 	 * <p/>
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * If you object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
@@ -911,11 +919,11 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * is an 'upsert'.
 	 * <p/>
 	 * The object is converted to the MongoDB native representation using an instance of {@see MongoConverter}. Unless
-	 * configured otherwise, an instance of MappingMongoConverter will be used.
+	 * configured otherwise, an instance of {@link MappingMongoConverter} will be used.
 	 * <p/>
 	 * If you object has an "Id' property, it will be set with the generated Id from MongoDB. If your Id property is a
 	 * String then MongoDB ObjectId will be used to populate that string. Otherwise, the conversion from ObjectId to your
-	 * property type will be handled by Spring's BeanWrapper class that leverages Type Cobnversion API. See <a
+	 * property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See <a
 	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert">Spring's
 	 * Type Conversion"</a> for more details.
 	 *
@@ -933,7 +941,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
 	 *          object. Must not be {@literal null}.
 	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult upsert(Query query, Update update, Class<?> entityClass);
 
@@ -943,11 +951,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
 	 * domain type information. Use {@link #upsert(Query, Update, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
+	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
+	 *          {@literal null}.
 	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 *          object. Must not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult upsert(Query query, Update update, String collectionName);
 
@@ -961,7 +970,7 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *          object. Must not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult upsert(Query query, Update update, Class<?> entityClass, String collectionName);
 
@@ -969,11 +978,12 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Updates the first object that is found in the collection of the entity class that matches the query document with
 	 * the provided update document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param entityClass class that determines the collection to use
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class that determines the collection to use.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult updateFirst(Query query, Update update, Class<?> entityClass);
 
@@ -985,24 +995,24 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult updateFirst(Query query, Update update, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
-	 * the provided updated document.
+	 * the provided updated document. <br />
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult updateFirst(Query query, Update update, Class<?> entityClass, String collectionName);
 
@@ -1012,10 +1022,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
-	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult updateMulti(Query query, Update update, Class<?> entityClass);
 
@@ -1027,10 +1037,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	UpdateResult updateMulti(Query query, Update update, String collectionName);
 
@@ -1040,38 +1050,38 @@ public interface MongoOperations extends FluentMongoOperations {
 	 *
 	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
 	 *          {@literal null}.
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object. Must not be {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
 	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
 	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
-	UpdateResult updateMulti(final Query query, final Update update, Class<?> entityClass, String collectionName);
+	UpdateResult updateMulti(Query query, Update update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Remove the given object from the collection by id.
 	 *
 	 * @param object must not be {@literal null}.
-	 * @return never {@literal null}.
-	 * @throws IllegalArgumentException when {@code object} to remove is {@literal null}.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	DeleteResult remove(Object object);
 
 	/**
 	 * Removes the given object from the given collection.
 	 *
-	 * @param object
-	 * @param collection must not be {@literal null} or empty.
-	 * @thorws IllegalArgumentException when {@code object} or {@code collection} is {@literal null}.
+	 * @param object must not be {@literal null}.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
-	DeleteResult remove(Object object, String collection);
+	DeleteResult remove(Object object, String collectionName);
 
 	/**
 	 * Remove all documents that match the provided query document criteria from the the collection used to store the
 	 * entityClass. The Class parameter is also used to help convert the Id of the object if it is present in the query.
 	 *
-	 * @param query
-	 * @param entityClass
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param entityClass class that determines the collection to use.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	DeleteResult remove(Query query, Class<?> entityClass);
 
@@ -1079,9 +1089,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * Remove all documents that match the provided query document criteria from the the collection used to store the
 	 * entityClass. The Class parameter is also used to help convert the Id of the object if it is present in the query.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @param collectionName
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param entityClass class of the pojo to be operated on. Can be {@literal null}.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	DeleteResult remove(Query query, Class<?> entityClass, String collectionName);
 
@@ -1091,8 +1102,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping is not available due to the lack of domain type
 	 * information. Use {@link #remove(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to remove a record
-	 * @param collectionName name of the collection where the objects will removed
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	DeleteResult remove(Query query, String collectionName);
 
@@ -1101,9 +1113,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping is not available due to the lack of domain type
 	 * information. Use {@link #findAllAndRemove(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query must not be {@literal null}.
-	 * @param collectionName must not be {@literal null}.
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link List} converted objects deleted by this operation.
 	 * @since 1.5
 	 */
 	<T> List<T> findAllAndRemove(Query query, String collectionName);
@@ -1111,9 +1123,9 @@ public interface MongoOperations extends FluentMongoOperations {
 	/**
 	 * Returns and removes all documents matching the given query form the collection used to store the entityClass.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param entityClass class of the pojo to be operated on.
+	 * @return the {@link List} converted objects deleted by this operation.
 	 * @since 1.5
 	 */
 	<T> List<T> findAllAndRemove(Query query, Class<T> entityClass);
@@ -1123,10 +1135,10 @@ public interface MongoOperations extends FluentMongoOperations {
 	 * store the entityClass. The Class parameter is also used to help convert the Id of the object if it is present in
 	 * the query.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @param collectionName
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param entityClass class of the pojo to be operated on.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link List} converted objects deleted by this operation.
 	 * @since 1.5
 	 */
 	<T> List<T> findAllAndRemove(Query query, Class<T> entityClass, String collectionName);
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java
index deb5f7edb..225f623e6 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java
@@ -1475,12 +1475,12 @@ public class MongoTemplate implements MongoOperations, ApplicationContextAware,
 	}
 
 	@Override
-	public DeleteResult remove(Object object, String collection) {
+	public DeleteResult remove(Object object, String collectionName) {
 
 		Assert.notNull(object, "Object must not be null!");
-		Assert.hasText(collection, "Collection name must not be null or empty!");
+		Assert.hasText(collectionName, "Collection name must not be null or empty!");
 
-		return doRemove(collection, getIdQueryFor(object), object.getClass());
+		return doRemove(collectionName, getIdQueryFor(object), object.getClass());
 	}
 
 	/**
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
index 679ff5a1d..2d825a944 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
@@ -15,7 +15,6 @@
  */
 package org.springframework.data.mongodb.core;
 
-import org.springframework.lang.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -36,6 +35,7 @@ import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.NearQuery;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.lang.Nullable;
 
 import com.mongodb.ReadPreference;
 import com.mongodb.client.result.DeleteResult;
@@ -61,6 +61,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Returns the reactive operations that can be performed on indexes
 	 *
+	 * @param collectionName must not be {@literal null}.
 	 * @return index operations on the named collection
 	 */
 	ReactiveIndexOperations indexOps(String collectionName);
@@ -68,13 +69,14 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Returns the reactive operations that can be performed on indexes
 	 *
+	 * @param entityClass must not be {@literal null}.
 	 * @return index operations on the named collection associated with the given entity class
 	 */
 	ReactiveIndexOperations indexOps(Class<?> entityClass);
 
 	/**
 	 * Execute the a MongoDB command expressed as a JSON string. This will call the method JSON.parse that is part of the
-	 * MongoDB driver to convert the JSON string to a DBObject. Any errors that result from executing this command will be
+	 * MongoDB driver to convert the JSON string to a Document. Any errors that result from executing this command will be
 	 * converted into Spring's DAO exception hierarchy.
 	 *
 	 * @param jsonCommand a MongoDB command expressed as a JSON string.
@@ -86,7 +88,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Execute a MongoDB command. Any errors that result from executing this command will be converted into Spring's DAO
 	 * exception hierarchy.
 	 *
-	 * @param command a MongoDB command
+	 * @param command a MongoDB command.
 	 * @return a result object returned by the action
 	 */
 	Mono<Document> executeCommand(Document command);
@@ -97,7 +99,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param command a MongoDB command, must not be {@literal null}.
 	 * @param readPreference read preferences to use, can be {@literal null}.
-	 * @return a result object returned by the action
+	 * @return a result object returned by the action.
 	 */
 	Mono<Document> executeCommand(Document command, @Nullable ReadPreference readPreference);
 
@@ -106,8 +108,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
-	 * @param <T> return type
-	 * @param action callback object that specifies the MongoDB actions to perform on the passed in DB instance.
+	 * @param action callback object that specifies the MongoDB actions to perform on the passed in DB instance. Must not
+	 *          be {@literal null}.
+	 * @param <T> return type.
 	 * @return a result object returned by the action
 	 */
 	<T> Flux<T> execute(ReactiveDatabaseCallback<T> action);
@@ -117,10 +120,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
-	 * @param entityClass class that determines the collection to use
-	 * @param <T> return type
-	 * @param action callback object that specifies the MongoDB action
-	 * @return a result object returned by the action or <tt>null</tt>
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @param action callback object that specifies the MongoDB action. Must not be {@literal null}.
+	 * @param <T> return type.
+	 * @return a result object returned by the action or {@literal null}.
 	 */
 	<T> Flux<T> execute(Class<?> entityClass, ReactiveCollectionCallback<T> action);
 
@@ -129,51 +132,53 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Allows for returning a result object, that is a domain object or a collection of domain objects.
 	 *
-	 * @param <T> return type
-	 * @param collectionName the name of the collection that specifies which DBCollection instance will be passed into
-	 * @param action callback object that specifies the MongoDB action the callback action.
-	 * @return a result object returned by the action or <tt>null</tt>
+	 * @param collectionName the name of the collection that specifies which {@link MongoCollection} instance will be
+	 *          passed into. Must not be {@literal null} or empty.
+	 * @param action callback object that specifies the MongoDB action the callback action. Must not be {@literal null}.
+	 * @param <T> return type.
+	 * @return a result object returned by the action or {@literal null}.
 	 */
 	<T> Flux<T> execute(String collectionName, ReactiveCollectionCallback<T> action);
 
 	/**
 	 * Create an uncapped collection with a name based on the provided entity class.
 	 *
-	 * @param entityClass class that determines the collection to create
-	 * @return the created collection
+	 * @param entityClass class that determines the collection to create.
+	 * @return the created collection.
 	 */
 	<T> Mono<MongoCollection<Document>> createCollection(Class<T> entityClass);
 
 	/**
 	 * Create a collection with a name based on the provided entity class using the options.
 	 *
-	 * @param entityClass class that determines the collection to create
+	 * @param entityClass class that determines the collection to create. Must not be {@literal null}.
 	 * @param collectionOptions options to use when creating the collection.
-	 * @return the created collection
+	 * @return the created collection.
 	 */
-	<T> Mono<MongoCollection<Document>> createCollection(Class<T> entityClass, CollectionOptions collectionOptions);
+	<T> Mono<MongoCollection<Document>> createCollection(Class<T> entityClass,
+			@Nullable CollectionOptions collectionOptions);
 
 	/**
 	 * Create an uncapped collection with the provided name.
 	 *
-	 * @param collectionName name of the collection
-	 * @return the created collection
+	 * @param collectionName name of the collection.
+	 * @return the created collection.
 	 */
 	Mono<MongoCollection<Document>> createCollection(String collectionName);
 
 	/**
 	 * Create a collection with the provided name and options.
 	 *
-	 * @param collectionName name of the collection
+	 * @param collectionName name of the collection. Must not be {@literal null} nor empty.
 	 * @param collectionOptions options to use when creating the collection.
-	 * @return the created collection
+	 * @return the created collection.
 	 */
 	Mono<MongoCollection<Document>> createCollection(String collectionName, CollectionOptions collectionOptions);
 
 	/**
 	 * A set of collection names.
 	 *
-	 * @return Flux of collection names
+	 * @return Flux of collection names.
 	 */
 	Flux<String> getCollectionNames();
 
@@ -182,7 +187,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
-	 * @param collectionName name of the collection
+	 * @param collectionName name of the collection.
 	 * @return an existing collection or a newly created one.
 	 */
 	MongoCollection<Document> getCollection(String collectionName);
@@ -192,7 +197,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
-	 * @param entityClass class that determines the name of the collection
+	 * @param entityClass class that determines the name of the collection. Must not be {@literal null}.
 	 * @return true if a collection with the given name is found, false otherwise.
 	 */
 	<T> Mono<Boolean> collectionExists(Class<T> entityClass);
@@ -202,7 +207,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
-	 * @param collectionName name of the collection
+	 * @param collectionName name of the collection. Must not be {@literal null}.
 	 * @return true if a collection with the given name is found, false otherwise.
 	 */
 	Mono<Boolean> collectionExists(String collectionName);
@@ -212,7 +217,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Translate any exceptions as necessary.
 	 *
-	 * @param entityClass class that determines the collection to drop/delete.
+	 * @param entityClass class that determines the collection to drop/delete. Must not be {@literal null}.
 	 */
 	<T> Mono<Void> dropCollection(Class<T> entityClass);
 
@@ -235,7 +240,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
 	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @return the converted collection
+	 * @return the converted collection.
 	 */
 	<T> Flux<T> findAll(Class<T> entityClass);
 
@@ -249,8 +254,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * to map objects since the test for class type is done in the client and not on the server.
 	 *
 	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the converted collection
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the converted collection.
 	 */
 	<T> Flux<T> findAll(Class<T> entityClass, String collectionName);
 
@@ -265,9 +270,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Mono}.
-	 * @return the converted object
+	 * @return the converted object.
 	 */
 	<T> Mono<T> findOne(Query query, Class<T> entityClass);
 
@@ -282,10 +287,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Mono}.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the converted object
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the converted object.
 	 */
 	<T> Mono<T> findOne(Query query, Class<T> entityClass, String collectionName);
 
@@ -296,7 +301,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param collectionName name of the collection to check for objects.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	Mono<Boolean> exists(Query query, String collectionName);
 
@@ -305,7 +310,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param entityClass the parametrized type.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	Mono<Boolean> exists(Query query, Class<?> entityClass);
 
@@ -315,7 +320,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * @param query the {@link Query} class that specifies the criteria used to find a record.
 	 * @param entityClass the parametrized type. Can be {@literal null}.
 	 * @param collectionName name of the collection to check for objects.
-	 * @return
+	 * @return {@literal true} if the query yields a result.
 	 */
 	Mono<Boolean> exists(Query query, @Nullable Class<?> entityClass, String collectionName);
 
@@ -329,9 +334,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
-	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @return the {@link Flux} of converted objects
+	 *          specification. Must not be {@literal null}.
+	 * @param entityClass the parametrized type of the returned {@link Flux}. Must not be {@literal null}.
+	 * @return the {@link Flux} of converted objects.
 	 */
 	<T> Flux<T> find(Query query, Class<T> entityClass);
 
@@ -345,10 +350,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification. Must not be {@literal null}.
 	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the {@link Flux} of converted objects
+	 * @param collectionName name of the collection to retrieve the objects from. Must not be {@literal null}.
+	 * @return the {@link Flux} of converted objects.
 	 */
 	<T> Flux<T> find(Query query, Class<T> entityClass, String collectionName);
 
@@ -356,9 +361,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Returns a document with the given id mapped onto the given class. The collection the query is ran against will be
 	 * derived from the given target class as well.
 	 *
-	 * @param <T>
-	 * @param id the id of the document to return.
-	 * @param entityClass the type the document shall be converted into.
+	 * @param id the id of the document to return. Must not be {@literal null}.
+	 * @param entityClass the type the document shall be converted into. Must not be {@literal null}.
 	 * @return the document with the given id mapped onto the given target class.
 	 */
 	<T> Mono<T> findById(Object id, Class<T> entityClass);
@@ -366,11 +370,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	/**
 	 * Returns the document with the given id from the given collection mapped onto the given target class.
 	 *
-	 * @param id the id of the document to return
-	 * @param entityClass the type to convert the document to
-	 * @param collectionName the collection to query for the document
-	 * @param <T>
-	 * @return
+	 * @param id the id of the document to return.
+	 * @param entityClass the type to convert the document to.
+	 * @param collectionName the collection to query for the document.
+	 * @return the converted object.
 	 */
 	<T> Mono<T> findById(Object id, Class<T> entityClass, String collectionName);
 
@@ -459,7 +462,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 *
 	 * @param near must not be {@literal null}.
 	 * @param entityClass must not be {@literal null}.
-	 * @return
+	 * @return the converted {@link GeoResult}s.
 	 */
 	<T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<T> entityClass);
 
@@ -472,37 +475,37 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * @param entityClass must not be {@literal null}.
 	 * @param collectionName the collection to trigger the query against. If no collection name is given the entity class
 	 *          will be inspected.
-	 * @return
+	 * @return the converted {@link GeoResult}s.
 	 */
 	<T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
-	 *          fields specification.
-	 * @param update the {@link Update} to apply on matching documents.
-	 * @param entityClass the parametrized type.
-	 * @return
+	 *          fields specification. Must not be {@literal null}.
+	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param entityClass the parametrized type. Must not be {@literal null}.
+	 * @return the converted object that was updated before it was updated.
 	 */
 	<T> Mono<T> findAndModify(Query query, Update update, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query}.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
-	 *          fields specification.
-	 * @param update the {@link Update} to apply on matching documents.
-	 * @param entityClass the parametrized type.
-	 * @param collectionName the collection to query.
-	 * @return
+	 *          fields specification. Must not be {@literal null}.
+	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param entityClass the parametrized type. Must not be {@literal null}.
+	 * @param collectionName the collection to query. Must not be {@literal null}.
+	 * @return the converted object that was updated before it was updated.
 	 */
 	<T> Mono<T> findAndModify(Query query, Update update, Class<T> entityClass, String collectionName);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
@@ -511,22 +514,24 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * @param update the {@link Update} to apply on matching documents.
 	 * @param options the {@link FindAndModifyOptions} holding additional information.
 	 * @param entityClass the parametrized type.
-	 * @return
+	 * @return the converted object that was updated. Depending on the value of {@link FindAndModifyOptions#isReturnNew()}
+	 *         this will either be the object as it was before the update or as it is after the update.
 	 */
 	<T> Mono<T> findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass);
 
 	/**
-	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify <a/>
+	 * Triggers <a href="https://docs.mongodb.org/manual/reference/method/db.collection.findAndModify/">findAndModify<a/>
 	 * to apply provided {@link Update} on documents matching {@link Criteria} of given {@link Query} taking
 	 * {@link FindAndModifyOptions} into account.
 	 *
 	 * @param query the {@link Query} class that specifies the {@link Criteria} used to find a record and also an optional
-	 *          fields specification.
-	 * @param update the {@link Update} to apply on matching documents.
-	 * @param options the {@link FindAndModifyOptions} holding additional information.
-	 * @param entityClass the parametrized type.
-	 * @param collectionName the collection to query.
-	 * @return
+	 *          fields specification. Must not be {@literal null}.
+	 * @param update the {@link Update} to apply on matching documents. Must not be {@literal null}.
+	 * @param options the {@link FindAndModifyOptions} holding additional information. Must not be {@literal null}.
+	 * @param entityClass the parametrized type. Must not be {@literal null}.
+	 * @param collectionName the collection to query. Must not be {@literal null}.
+	 * @return the converted object that was updated. Depending on the value of {@link FindAndModifyOptions#isReturnNew()}
+	 *         this will either be the object as it was before the update or as it is after the update.
 	 */
 	<T> Mono<T> findAndModify(Query query, Update update, FindAndModifyOptions options, Class<T> entityClass,
 			String collectionName);
@@ -542,7 +547,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Mono}.
 	 * @return the converted object
 	 */
@@ -559,19 +564,20 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Mono}.
 	 * @param collectionName name of the collection to retrieve the objects from.
-	 * @return the converted object
+	 * @return the converted object.
 	 */
 	<T> Mono<T> findAndRemove(Query query, Class<T> entityClass, String collectionName);
 
 	/**
 	 * Returns the number of documents for the given {@link Query} by querying the collection of the given entity class.
 	 *
-	 * @param query
-	 * @param entityClass must not be {@literal null}.
-	 * @return
+	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
+	 *          {@literal null}.
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the count of matching documents.
 	 */
 	Mono<Long> count(Query query, Class<?> entityClass);
 
@@ -580,9 +586,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * must solely consist of document field references as we lack type information to map potential property references
 	 * onto document fields. Use {@link #count(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query
+	 * @param query the {@link Query} class that specifies the criteria used to find documents.
 	 * @param collectionName must not be {@literal null} or empty.
-	 * @return
+	 * @return the count of matching documents.
 	 * @see #count(Query, Class, String)
 	 */
 	Mono<Long> count(Query query, String collectionName);
@@ -591,12 +597,13 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Returns the number of documents for the given {@link Query} by querying the given collection using the given entity
 	 * class to map the given {@link Query}.
 	 *
-	 * @param query
-	 * @param entityClass must not be {@literal null}.
+	 * @param query the {@link Query} class that specifies the criteria used to find documents. Must not be
+	 *          {@literal null}.
+	 * @param entityClass the parametrized type. Can be {@literal null}.
 	 * @param collectionName must not be {@literal null} or empty.
-	 * @return
+	 * @return the count of matching documents.
 	 */
-	Mono<Long> count(Query query, Class<?> entityClass, String collectionName);
+	Mono<Long> count(Query query, @Nullable Class<?> entityClass, String collectionName);
 
 	/**
 	 * Insert the object into the collection for the entity type of the object to save.
@@ -612,8 +619,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
 	 *
-	 * @param objectToSave the object to store in the collection.
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> insert(T objectToSave);
 
@@ -625,27 +632,27 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
 	 *
-	 * @param objectToSave the object to store in the collection
-	 * @param collectionName name of the collection to store the object in
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> insert(T objectToSave, String collectionName);
 
 	/**
 	 * Insert a Collection of objects into a collection in a single batch write to the database.
 	 *
-	 * @param batchToSave the batch of objects to save.
-	 * @param entityClass class that determines the collection to use
-	 * @return
+	 * @param batchToSave the batch of objects to save. Must not be {@literal null}.
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insert(Collection<? extends T> batchToSave, Class<?> entityClass);
 
 	/**
 	 * Insert a batch of objects into the specified collection in a single batch write to the database.
 	 *
-	 * @param batchToSave the list of objects to save.
-	 * @param collectionName name of the collection to store the object in
-	 * @return
+	 * @param batchToSave the list of objects to save. Must not be {@literal null}.
+	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insert(Collection<? extends T> batchToSave, String collectionName);
 
@@ -653,8 +660,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Insert a mixed Collection of objects into a database collection determining the collection name to use based on the
 	 * class.
 	 *
-	 * @param objectsToSave the list of objects to save.
-	 * @return
+	 * @param objectsToSave the list of objects to save. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insertAll(Collection<? extends T> objectsToSave);
 
@@ -672,26 +679,26 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <p/>
 	 * Insert is used to initially store the object into the database. To update an existing object use the save method.
 	 *
-	 * @param objectToSave the object to store in the collection.
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> insert(Mono<? extends T> objectToSave);
 
 	/**
 	 * Insert a Collection of objects into a collection in a single batch write to the database.
 	 *
-	 * @param batchToSave the publisher which provides objects to save.
-	 * @param entityClass class that determines the collection to use
-	 * @return
+	 * @param batchToSave the publisher which provides objects to save. Must not be {@literal null}.
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, Class<?> entityClass);
 
 	/**
 	 * Insert objects into the specified collection in a single batch write to the database.
 	 *
-	 * @param batchToSave the publisher which provides objects to save.
-	 * @param collectionName name of the collection to store the object in
-	 * @return
+	 * @param batchToSave the publisher which provides objects to save. Must not be {@literal null}.
+	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, String collectionName);
 
@@ -699,8 +706,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Insert a mixed Collection of objects into a database collection determining the collection name to use based on the
 	 * class.
 	 *
-	 * @param objectsToSave the publisher which provides objects to save.
-	 * @return
+	 * @param objectsToSave the publisher which provides objects to save. Must not be {@literal null}.
+	 * @return the saved objects.
 	 */
 	<T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> objectsToSave);
 
@@ -717,8 +724,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert" >
 	 * Spring's Type Conversion"</a> for more details.
 	 *
-	 * @param objectToSave the object to store in the collection
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> save(T objectToSave);
 
@@ -735,9 +742,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert">Spring's
 	 * Type Conversion"</a> for more details.
 	 *
-	 * @param objectToSave the object to store in the collection
-	 * @param collectionName name of the collection to store the object in
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> save(T objectToSave, String collectionName);
 
@@ -754,8 +761,8 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <a href="http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert" >
 	 * Spring's Type Conversion"</a> for more details.
 	 *
-	 * @param objectToSave the object to store in the collection
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> save(Mono<? extends T> objectToSave);
 
@@ -772,9 +779,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * http://docs.spring.io/spring/docs/current/spring-framework-reference/html/validation.html#core-convert">Spring's
 	 * Type Conversion"</a> for more details.
 	 *
-	 * @param objectToSave the object to store in the collection
-	 * @param collectionName name of the collection to store the object in
-	 * @return
+	 * @param objectToSave the object to store in the collection. Must not be {@literal null}.
+	 * @param collectionName name of the collection to store the object in. Must not be {@literal null}.
+	 * @return the saved object.
 	 */
 	<T> Mono<T> save(Mono<? extends T> objectToSave, String collectionName);
 
@@ -782,10 +789,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be upserted
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing object
-	 * @param entityClass class that determines the collection to use
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
+	 *          object. Must not be {@literal null}.
+	 * @param entityClass class that determines the collection to use. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> upsert(Query query, Update update, Class<?> entityClass);
 
@@ -795,11 +804,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
 	 * domain type information. Use {@link #upsert(Query, Update, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
+	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
+	 *          {@literal null}.
 	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 *          object. Must not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> upsert(Query query, Update update, String collectionName);
 
@@ -807,11 +817,13 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Performs an upsert. If no document is found that matches the query, a new document is created and inserted by
 	 * combining the query document and the update document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be upserted
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing object
-	 * @param entityClass class of the pojo to be operated on
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be upserted. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
+	 *          object. Must not be {@literal null}.
+	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> upsert(Query query, Update update, Class<?> entityClass, String collectionName);
 
@@ -819,11 +831,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Updates the first object that is found in the collection of the entity class that matches the query document with
 	 * the provided update document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param entityClass class that determines the collection to use
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class that determines the collection to use.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> updateFirst(Query query, Update update, Class<?> entityClass);
 
@@ -833,26 +846,26 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
 	 * domain type information. Use {@link #updateFirst(Query, Update, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> updateFirst(Query query, Update update, String collectionName);
 
 	/**
 	 * Updates the first object that is found in the specified collection that matches the query document criteria with
 	 * the provided updated document. <br />
-	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
-	 * domain type information. Use {@link #updateFirst(Query, Update, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param entityClass class of the pojo to be operated on
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> updateFirst(Query query, Update update, Class<?> entityClass, String collectionName);
 
@@ -860,11 +873,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
 	 * with the provided updated document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param entityClass class that determines the collection to use
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> updateMulti(Query query, Update update, Class<?> entityClass);
 
@@ -874,11 +888,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping, versions, etc. is not available due to the lack of
 	 * domain type information. Use {@link #updateMulti(Query, Update, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
 	Mono<UpdateResult> updateMulti(Query query, Update update, String collectionName);
 
@@ -886,20 +901,21 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Updates all objects that are found in the collection for the entity class that matches the query document criteria
 	 * with the provided updated document.
 	 *
-	 * @param query the query document that specifies the criteria used to select a record to be updated
-	 * @param update the update document that contains the updated object or $ operators to manipulate the existing
-	 *          object.
-	 * @param entityClass class of the pojo to be operated on
-	 * @param collectionName name of the collection to update the object in
-	 * @return the WriteResult which lets you access the results of the previous write.
+	 * @param query the query document that specifies the criteria used to select a record to be updated. Must not be
+	 *          {@literal null}.
+	 * @param update the update document that contains the updated object or $ operators to manipulate the existing. Must
+	 *          not be {@literal null}.
+	 * @param entityClass class of the pojo to be operated on. Must not be {@literal null}.
+	 * @param collectionName name of the collection to update the object in. Must not be {@literal null}.
+	 * @return the {@link UpdateResult} which lets you access the results of the previous write.
 	 */
-	Mono<UpdateResult> updateMulti(final Query query, final Update update, Class<?> entityClass, String collectionName);
+	Mono<UpdateResult> updateMulti(Query query, Update update, Class<?> entityClass, String collectionName);
 
 	/**
 	 * Remove the given object from the collection by id.
 	 *
 	 * @param object must not be {@literal null}.
-	 * @return
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	Mono<DeleteResult> remove(Object object);
 
@@ -907,34 +923,35 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Removes the given object from the given collection.
 	 *
 	 * @param object must not be {@literal null}.
-	 * @param collection must not be {@literal null} or empty.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
-	Mono<DeleteResult> remove(Object object, String collection);
+	Mono<DeleteResult> remove(Object object, String collectionName);
 
 	/**
 	 * Remove the given object from the collection by id.
 	 *
-	 * @param objectToRemove
-	 * @return
+	 * @param objectToRemove must not be {@literal null}.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	Mono<DeleteResult> remove(Mono<? extends Object> objectToRemove);
 
 	/**
 	 * Removes the given object from the given collection.
 	 *
-	 * @param objectToRemove
-	 * @param collection must not be {@literal null} or empty.
-	 * @return
+	 * @param objectToRemove must not be {@literal null}.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
-	Mono<DeleteResult> remove(Mono<? extends Object> objectToRemove, String collection);
+	Mono<DeleteResult> remove(Mono<? extends Object> objectToRemove, String collectionName);
 
 	/**
 	 * Remove all documents that match the provided query document criteria from the the collection used to store the
 	 * entityClass. The Class parameter is also used to help convert the Id of the object if it is present in the query.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @return
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param entityClass class that determines the collection to use.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	Mono<DeleteResult> remove(Query query, Class<?> entityClass);
 
@@ -942,12 +959,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * Remove all documents that match the provided query document criteria from the the collection used to store the
 	 * entityClass. The Class parameter is also used to help convert the Id of the object if it is present in the query.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @param collectionName
-	 * @return
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param entityClass class of the pojo to be operated on. Can be {@literal null}.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
-	Mono<DeleteResult> remove(Query query, Class<?> entityClass, String collectionName);
+	Mono<DeleteResult> remove(Query query, @Nullable Class<?> entityClass, String collectionName);
 
 	/**
 	 * Remove all documents from the specified collection that match the provided query document criteria. There is no
@@ -955,8 +972,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping is not available due to the lack of domain type
 	 * information. Use {@link #remove(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query the query document that specifies the criteria used to remove a record
-	 * @param collectionName name of the collection where the objects will removed
+	 * @param query the query document that specifies the criteria used to remove a record.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link DeleteResult} which lets you access the results of the previous delete.
 	 */
 	Mono<DeleteResult> remove(Query query, String collectionName);
 
@@ -965,18 +983,18 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * <strong>NOTE:</strong> Any additional support for field mapping is not available due to the lack of domain type
 	 * information. Use {@link #findAllAndRemove(Query, Class, String)} to get full type specific support.
 	 *
-	 * @param query
-	 * @param collectionName
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link Flux} converted objects deleted by this operation.
 	 */
 	<T> Flux<T> findAllAndRemove(Query query, String collectionName);
 
 	/**
 	 * Returns and removes all documents matching the given query form the collection used to store the entityClass.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param entityClass class of the pojo to be operated on.
+	 * @return the {@link Flux} converted objects deleted by this operation.
 	 */
 	<T> Flux<T> findAllAndRemove(Query query, Class<T> entityClass);
 
@@ -985,10 +1003,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * store the entityClass. The Class parameter is also used to help convert the Id of the object if it is present in
 	 * the query.
 	 *
-	 * @param query
-	 * @param entityClass
-	 * @param collectionName
-	 * @return
+	 * @param query the query document that specifies the criteria used to find and remove documents.
+	 * @param entityClass class of the pojo to be operated on.
+	 * @param collectionName name of the collection where the objects will removed, must not be {@literal null} or empty.
+	 * @return the {@link Flux} converted objects deleted by this operation.
 	 */
 	<T> Flux<T> findAllAndRemove(Query query, Class<T> entityClass, String collectionName);
 
@@ -1005,9 +1023,9 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @return the {@link Flux} of converted objects
+	 * @return the {@link Flux} of converted objects.
 	 */
 	<T> Flux<T> tail(Query query, Class<T> entityClass);
 
@@ -1024,10 +1042,10 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
 	 * feature rich {@link Query}.
 	 *
 	 * @param query the query class that specifies the criteria used to find a record and also an optional fields
-	 *          specification
+	 *          specification.
 	 * @param entityClass the parametrized type of the returned {@link Flux}.
-	 * @param collectionName name of the collection to retrieve the objects from
-	 * @return the {@link Flux} of converted objects
+	 * @param collectionName name of the collection to retrieve the objects from.
+	 * @return the {@link Flux} of converted objects.
 	 */
 	<T> Flux<T> tail(Query query, Class<T> entityClass, String collectionName);
 
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java
index d3627777e..6b9e97bb6 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java
@@ -489,7 +489,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#createCollection(java.lang.Class, org.springframework.data.mongodb.core.CollectionOptions)
 	 */
 	public <T> Mono<MongoCollection<Document>> createCollection(Class<T> entityClass,
-			CollectionOptions collectionOptions) {
+			@Nullable CollectionOptions collectionOptions) {
 		return createCollection(determineCollectionName(entityClass), collectionOptions);
 	}
 
@@ -928,12 +928,15 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	@Override
 	public <T> Mono<T> insert(Mono<? extends T> objectToSave) {
+
+		Assert.notNull(objectToSave, "Mono to insert must not be null!");
+
 		return objectToSave.flatMap(this::insert);
 	}
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insert(org.reactivestreams.Publisher, java.lang.Class)
+	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insert(reactor.core.publisher.Mono, java.lang.Class)
 	 */
 	@Override
 	public <T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, Class<?> entityClass) {
@@ -942,10 +945,13 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insert(org.reactivestreams.Publisher, java.lang.String)
+	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insert(reactor.core.publisher.Mono, java.lang.String)
 	 */
 	@Override
 	public <T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> batchToSave, String collectionName) {
+
+		Assert.notNull(batchToSave, "Batch to insert must not be null!");
+
 		return Flux.from(batchToSave).flatMap(collection -> insert(collection, collectionName));
 	}
 
@@ -955,6 +961,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	public <T> Mono<T> insert(T objectToSave) {
 
+		Assert.notNull(objectToSave, "Object to insert must not be null!");
+
 		ensureNotIterable(objectToSave);
 		return insert(objectToSave, determineEntityCollectionName(objectToSave));
 	}
@@ -965,6 +973,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	public <T> Mono<T> insert(T objectToSave, String collectionName) {
 
+		Assert.notNull(objectToSave, "Object to insert must not be null!");
+
 		ensureNotIterable(objectToSave);
 		return doInsert(collectionName, objectToSave, this.mongoConverter);
 	}
@@ -1018,7 +1028,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insertAll(org.reactivestreams.Publisher)
+	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#insertAll(reactor.core.publisher.Mono)
 	 */
 	@Override
 	public <T> Flux<T> insertAll(Mono<? extends Collection<? extends T>> objectsToSave) {
@@ -1088,6 +1098,9 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	@Override
 	public <T> Mono<T> save(Mono<? extends T> objectToSave) {
+
+		Assert.notNull(objectToSave, "Mono to save must not be null!");
+
 		return objectToSave.flatMap(this::save);
 	}
 
@@ -1097,6 +1110,9 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	@Override
 	public <T> Mono<T> save(Mono<? extends T> objectToSave, String collectionName) {
+
+		Assert.notNull(objectToSave, "Mono to save must not be null!");
+
 		return objectToSave.flatMap(o -> save(o, collectionName));
 	}
 
@@ -1445,8 +1461,8 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#remove(reactor.core.publisher.Mono, java.lang.String)
 	 */
 	@Override
-	public Mono<DeleteResult> remove(Mono<? extends Object> objectToRemove, String collection) {
-		return objectToRemove.flatMap(it -> remove(it, collection));
+	public Mono<DeleteResult> remove(Mono<? extends Object> objectToRemove, String collectionName) {
+		return objectToRemove.flatMap(it -> remove(it, collectionName));
 	}
 
 	/*
@@ -1464,12 +1480,12 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#remove(java.lang.Object, java.lang.String)
 	 */
-	public Mono<DeleteResult> remove(Object object, String collection) {
+	public Mono<DeleteResult> remove(Object object, String collectionName) {
 
 		Assert.notNull(object, "Object must not be null!");
-		Assert.hasText(collection, "Collection name must not be null or empty!");
+		Assert.hasText(collectionName, "Collection name must not be null or empty!");
 
-		return doRemove(collection, getIdQueryFor(object), object.getClass());
+		return doRemove(collectionName, getIdQueryFor(object), object.getClass());
 	}
 
 	/**
@@ -1582,8 +1598,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		return doRemove(collectionName, query, entityClass);
 	}
 
-	protected <T> Mono<DeleteResult> doRemove(final String collectionName, final Query query,
-			final Class<T> entityClass) {
+	protected <T> Mono<DeleteResult> doRemove(String collectionName, Query query, @Nullable Class<T> entityClass) {
 
 		if (query == null) {
 			throw new InvalidDataAccessApiUsageException("Query passed in to remove can't be null!");
@@ -1645,8 +1660,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 */
 	@Override
 	public <T> Flux<T> findAllAndRemove(Query query, String collectionName) {
-
-		return findAllAndRemove(query, null, collectionName);
+		return (Flux<T>) findAllAndRemove(query, Object.class, collectionName);
 	}
 
 	/*
@@ -1663,7 +1677,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#findAllAndRemove(org.springframework.data.mongodb.core.query.Query, java.lang.Class, java.lang.String)
 	 */
 	@Override
-	public <T> Flux<T> findAllAndRemove(Query query, @Nullable Class<T> entityClass, String collectionName) {
+	public <T> Flux<T> findAllAndRemove(Query query, Class<T> entityClass, String collectionName) {
 		return doFindAndDelete(collectionName, query, entityClass);
 	}
 
@@ -1681,7 +1695,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @see org.springframework.data.mongodb.core.ReactiveMongoOperations#tail(org.springframework.data.mongodb.core.query.Query, java.lang.Class, java.lang.String)
 	 */
 	@Override
-	public <T> Flux<T> tail(Query query, Class<T> entityClass, String collectionName) {
+	public <T> Flux<T> tail(@Nullable Query query, Class<T> entityClass, String collectionName) {
 
 		if (query == null) {
 
@@ -1938,7 +1952,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @return the List of converted objects.
 	 */
 	protected <T> Mono<T> doFindAndRemove(String collectionName, Document query, Document fields, Document sort,
-			Collation collation, Class<T> entityClass) {
+			@Nullable Collation collation, Class<T> entityClass) {
 
 		if (LOGGER.isDebugEnabled()) {
 			LOGGER.debug(String.format("findAndRemove using query: %s fields: %s sort: %s for class: %s in collection: %s",
@@ -1955,8 +1969,6 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	protected <T> Mono<T> doFindAndModify(String collectionName, Document query, Document fields, Document sort,
 			Class<T> entityClass, Update update, FindAndModifyOptions options) {
 
-		FindAndModifyOptions optionsToUse = options != null ? options : new FindAndModifyOptions();
-
 		MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityClass);
 
 		return Mono.defer(() -> {
@@ -1973,7 +1985,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 						collectionName));
 			}
 
-			return executeFindOneInternal(new FindAndModifyCallback(mappedQuery, fields, sort, mappedUpdate, optionsToUse),
+			return executeFindOneInternal(new FindAndModifyCallback(mappedQuery, fields, sort, mappedUpdate, options),
 					new ReadDocumentCallback<T>(this.mongoConverter, entityClass, collectionName), collectionName);
 		});
 	}
@@ -1990,7 +2002,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	 * @param savedObject
 	 * @param id
 	 */
-	private void populateIdIfNecessary(Object savedObject, Object id) {
+	private void populateIdIfNecessary(Object savedObject, @Nullable Object id) {
 
 		if (id == null) {
 			return;
@@ -2030,22 +2042,20 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 	}
 
 	protected void ensureNotIterable(Object o) {
-		if (null != o) {
 
-			boolean isIterable = o.getClass().isArray();
+		boolean isIterable = o.getClass().isArray();
 
-			if (!isIterable) {
-				for (Class iterableClass : ITERABLE_CLASSES) {
-					if (iterableClass.isAssignableFrom(o.getClass()) || o.getClass().getName().equals(iterableClass.getName())) {
-						isIterable = true;
-						break;
-					}
+		if (!isIterable) {
+			for (Class iterableClass : ITERABLE_CLASSES) {
+				if (iterableClass.isAssignableFrom(o.getClass()) || o.getClass().getName().equals(iterableClass.getName())) {
+					isIterable = true;
+					break;
 				}
 			}
+		}
 
-			if (isIterable) {
-				throw new IllegalArgumentException("Cannot use a collection here.");
-			}
+		if (isIterable) {
+			throw new IllegalArgumentException("Cannot use a collection here.");
 		}
 	}
 
@@ -2213,7 +2223,7 @@ public class ReactiveMongoTemplate implements ReactiveMongoOperations, Applicati
 		return null;
 	}
 
-	String determineCollectionName(Class<?> entityClass) {
+	String determineCollectionName(@Nullable Class<?> entityClass) {
 
 		if (entityClass == null) {
 			throw new InvalidDataAccessApiUsageException(
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateTests.java
index 710d482d9..43c0cbc4f 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateTests.java
@@ -461,6 +461,24 @@ public class ReactiveMongoTemplateTests {
 		StepVerifier.create(template.findOne(new Query(), Sample.class)).expectNext(data).verifyComplete();
 	}
 
+	@Test // DATAMONGO-1774
+	public void testFindAllAndRemoveByCollectionReturnsAndRemovesDocuments() {
+
+		Sample spring = new Sample("100", "spring");
+		Sample data = new Sample("200", "data");
+		Sample mongodb = new Sample("300", "mongodb");
+
+		StepVerifier.create(template.insert(Arrays.asList(spring, data, mongodb), Sample.class)) //
+				.expectNextCount(3) //
+				.verifyComplete();
+
+		Query qry = query(where("field").in("spring", "mongodb"));
+
+		StepVerifier.create(template.findAllAndRemove(qry, "sample")).expectNextCount(2).verifyComplete();
+
+		StepVerifier.create(template.findOne(new Query(), Sample.class)).expectNext(data).verifyComplete();
+	}
+
 	@Test(expected = IllegalArgumentException.class) // DATAMONGO-1774
 	public void removeWithNullShouldThrowError() {
 		template.remove((Object)null).subscribe();