Polishing.

src/main/java/org/springframework/session/data/mongo/AbstractMongoSessionConverter.java

@@ -80,11 +80,13 @@ public abstract class AbstractMongoSessionConverter implements GenericConverter
 		}
 
 		LOG.info("Creating TTL index on field " + EXPIRE_AT_FIELD_NAME);
+
 		sessionCollectionIndexes
 				.ensureIndex(new Index(EXPIRE_AT_FIELD_NAME, Sort.Direction.ASC).named(EXPIRE_AT_FIELD_NAME).expire(0));
 	}
 
 	protected String extractPrincipal(MongoSession expiringSession) {
+
 		return this.indexResolver.resolveIndexesFor(expiringSession)
 				.get(FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME);
 	}

src/main/java/org/springframework/session/data/mongo/JacksonMongoSessionConverter.java

@@ -20,8 +20,6 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 
-import com.fasterxml.jackson.annotation.JsonCreator;
-import com.fasterxml.jackson.annotation.JsonProperty;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.bson.Document;
@@ -35,6 +33,8 @@ import org.springframework.session.FindByIndexNameSessionRepository;
 import org.springframework.util.Assert;
 
 import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.PropertyAccessor;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.DeserializationFeature;
@@ -145,10 +145,10 @@ public class JacksonMongoSessionConverter extends AbstractMongoSessionConverter
 	 * Used to whitelist {@link MongoSession} for {@link SecurityJackson2Modules}.
 	 */
 	private static class MongoSessionMixin {
+
 		@JsonCreator
 		public MongoSessionMixin(@JsonProperty("_id") String id,
-								 @JsonProperty("intervalSeconds") long maxInactiveIntervalInSeconds) {
-		}
+				@JsonProperty("intervalSeconds") long maxInactiveIntervalInSeconds) {}
 	}
 
 	/**

src/main/java/org/springframework/session/data/mongo/JdkMongoSessionConverter.java

@@ -69,6 +69,7 @@ public class JdkMongoSessionConverter extends AbstractMongoSessionConverter {
 		Assert.notNull(serializer, "serializer cannot be null");
 		Assert.notNull(deserializer, "deserializer cannot be null");
 		Assert.notNull(maxInactiveInterval, "maxInactiveInterval cannot be null");
+
 		this.serializer = serializer;
 		this.deserializer = deserializer;
 		this.maxInactiveInterval = maxInactiveInterval;

src/main/java/org/springframework/session/data/mongo/MongoIndexedSessionRepository.java

@@ -132,6 +132,7 @@ public class MongoIndexedSessionRepository
 	public void deleteById(String id) {
 
 		Optional.ofNullable(findSession(id)).ifPresent(document -> {
+
 			MongoSession session = convertToSession(this.mongoSessionConverter, document);
 			if (session != null) {
 				publishEvent(new SessionDeletedEvent(this, session));

src/main/java/org/springframework/session/data/mongo/ReactiveMongoSessionRepository.java

@@ -19,12 +19,13 @@ import static org.springframework.data.mongodb.core.query.Criteria.*;
 import static org.springframework.data.mongodb.core.query.Query.*;
 import static org.springframework.session.data.mongo.MongoSessionUtils.*;
 
+import reactor.core.publisher.Mono;
+
 import java.time.Duration;
 
 import org.bson.Document;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import reactor.core.publisher.Mono;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ApplicationEvent;
 import org.springframework.context.ApplicationEventPublisher;
@@ -136,6 +137,7 @@ public class ReactiveMongoSessionRepository
 	public void afterPropertiesSet() {
 
 		if (this.blockingMongoOperations != null) {
+
 			IndexOperations indexOperations = this.blockingMongoOperations.indexOps(this.collectionName);
 			this.mongoSessionConverter.ensureIndexes(indexOperations);
 		}

src/main/java/org/springframework/session/data/mongo/config/annotation/web/reactive/ReactiveMongoWebSessionConfiguration.java

@@ -62,7 +62,6 @@ public class ReactiveMongoWebSessionConfiguration extends SpringWebSessionConfig
 	private ClassLoader classLoader;
 	private IndexResolver<MongoSession> indexResolver;
 
-
 	@Bean
 	public ReactiveMongoSessionRepository reactiveMongoSessionRepository(ReactiveMongoOperations operations) {
 
@@ -83,7 +82,7 @@ public class ReactiveMongoWebSessionConfiguration extends SpringWebSessionConfig
 			if (this.indexResolver != null) {
 				mongoSessionConverter.setIndexResolver(this.indexResolver);
 			}
-			
+
 			repository.setMongoSessionConverter(mongoSessionConverter);
 		}