DATAMONGO-2490 - Polishing.

Remove unnecessary code. Reuse session-associated collection when logging to avoid unqualified calls to MongoDbFactory.getMongoDatabase(). Create collection before transaction in test for compatibility with older MongoDB servers.

Original pull request: #875.

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

@@ -34,6 +34,7 @@ import org.aopalliance.intercept.MethodInvocation;
 import org.bson.Document;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.cglib.proxy.Callback;
 import org.springframework.cglib.proxy.Enhancer;
@@ -44,8 +45,8 @@ import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.mongodb.ClientSessionException;
 import org.springframework.data.mongodb.LazyLoadingException;
-import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.MongoDatabaseUtils;
+import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
 import org.springframework.lang.Nullable;
 import org.springframework.objenesis.ObjenesisStd;
@@ -115,14 +116,16 @@ public class DefaultDbRefResolver implements DbRefResolver {
 	@Override
 	public Document fetch(DBRef dbRef) {
 
+		MongoCollection<Document> mongoCollection = getCollection(dbRef);
+
 		if (LOGGER.isTraceEnabled()) {
 			LOGGER.trace("Fetching DBRef '{}' from {}.{}.", dbRef.getId(),
-					StringUtils.hasText(dbRef.getDatabaseName()) ? dbRef.getDatabaseName() : mongoDbFactory.getDb().getName(),
+					StringUtils.hasText(dbRef.getDatabaseName()) ? dbRef.getDatabaseName()
+							: mongoCollection.getNamespace().getDatabaseName(),
 					dbRef.getCollectionName());
 		}
 
-		StringUtils.hasText(dbRef.getDatabaseName());
-		return getCollection(dbRef).find(Filters.eq("_id", dbRef.getId())).first();
+		return mongoCollection.find(Filters.eq("_id", dbRef.getId())).first();
 	}
 
 	/*
@@ -153,15 +156,16 @@ public class DefaultDbRefResolver implements DbRefResolver {
 		}
 
 		DBRef databaseSource = refs.iterator().next();
+		MongoCollection<Document> mongoCollection = getCollection(databaseSource);
 
 		if (LOGGER.isTraceEnabled()) {
 			LOGGER.trace("Bulk fetching DBRefs {} from {}.{}.", ids,
 					StringUtils.hasText(databaseSource.getDatabaseName()) ? databaseSource.getDatabaseName()
-							: mongoDbFactory.getDb().getName(),
+							: mongoCollection.getNamespace().getDatabaseName(),
 					databaseSource.getCollectionName());
 		}
 
-		List<Document> result = getCollection(databaseSource) //
+		List<Document> result = mongoCollection //
 				.find(new Document("_id", new Document("$in", ids))) //
 				.into(new ArrayList<>());
 

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

@@ -45,6 +45,8 @@ import com.mongodb.client.MongoClient;
 import com.mongodb.client.ClientSession;
 
 /**
+ * Integration tests for {@link ClientSession} through {@link MongoTemplate#withSession(ClientSession)}.
+ *
  * @author Christoph Strobl
  * @author Mark Paluch
  */
@@ -61,7 +63,7 @@ public class ClientSessionTests {
 	MongoClient client;
 
 	@Before
-	public void setUp() {
+	void setUp() {
 
 		client = MongoTestUtils.replSetClient();
 
@@ -72,7 +74,7 @@ public class ClientSessionTests {
 	}
 
 	@Test // DATAMONGO-1880
-	public void shouldApplyClientSession() {
+	void shouldApplyClientSession() {
 
 		ClientSession session = client.startSession(ClientSessionOptions.builder().causallyConsistent(true).build());
 
@@ -89,7 +91,7 @@ public class ClientSessionTests {
 	}
 
 	@Test // DATAMONGO-2241
-	public void shouldReuseConfiguredInfrastructure() {
+	void shouldReuseConfiguredInfrastructure() {
 
 		ClientSession session = client.startSession(ClientSessionOptions.builder().causallyConsistent(true).build());
 
@@ -162,7 +164,7 @@ public class ClientSessionTests {
 		SomeDoc ref = new SomeDoc("ref-1", "da value");
 		WithDbRef source = new WithDbRef("source-1", "da source", ref);
 
-		ClientSession session = mongoClient.startSession(ClientSessionOptions.builder().causallyConsistent(true).build());
+		ClientSession session = client.startSession(ClientSessionOptions.builder().causallyConsistent(true).build());
 
 		assertThat(session.getOperationTime()).isNull();
 

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

@@ -111,6 +111,7 @@ public class PersonRepositoryTransactionalTests {
 	public void beforeTransaction() {
 
 		createOrReplaceCollection(DB_NAME, template.getCollectionName(Person.class), client);
+		createOrReplaceCollection(DB_NAME, template.getCollectionName(User.class), client);
 
 		durzo = new Person("Durzo", "Blint", 700);
 		kylar = new Person("Kylar", "Stern", 21);