DATAMONGO-2378 - Polishing.

Consistently use MongoTestUtils for client creations. Reuse MongoClient instead of opening always new client instances.

Original pull request: #793.

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

@@ -38,7 +38,7 @@ public class MongoAdmin implements MongoAdminOperations {
 
 	/**
 	 * @param mongoClient
-	 * @deprecated since 2.2 in favor of {@link MongoAdmin(com.mongodb.client.MongoClient)}.
+	 * @deprecated since 2.2 in favor of {@link MongoAdmin#MongoAdmin(com.mongodb.client.MongoClient)}.
 	 */
 	@Deprecated
 	public MongoAdmin(MongoClient mongoClient) {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/ReactiveTransactionIntegrationTests.java

@@ -85,13 +85,12 @@ public class ReactiveTransactionIntegrationTests {
 		personService = context.getBean(PersonService.class);
 		operations = context.getBean(ReactiveMongoOperations.class);
 
-		try (MongoClient client = MongoClients.create()) {
+		MongoClient client = MongoTestUtils.reactiveClient();
 
-			Flux.merge( //
-					MongoTestUtils.createOrReplaceCollection(DATABASE, operations.getCollectionName(Person.class), client),
-					MongoTestUtils.createOrReplaceCollection(DATABASE, operations.getCollectionName(EventLog.class), client) //
-			).then().as(StepVerifier::create).verifyComplete();
-		}
+		Flux.merge( //
+				MongoTestUtils.createOrReplaceCollection(DATABASE, operations.getCollectionName(Person.class), client),
+				MongoTestUtils.createOrReplaceCollection(DATABASE, operations.getCollectionName(EventLog.class), client) //
+		).then().as(StepVerifier::create).verifyComplete();
 	}
 
 	@Test // DATAMONGO-2265
@@ -224,7 +223,7 @@ public class ReactiveTransactionIntegrationTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create("mongodb://localhost");
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/config/AbstractIntegrationTests.java

@@ -27,6 +27,7 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.dao.DataAccessException;
 import org.springframework.data.mongodb.core.CollectionCallback;
 import org.springframework.data.mongodb.core.MongoOperations;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -52,7 +53,7 @@ public abstract class AbstractIntegrationTests {
 
 		@Override
 		public MongoClient mongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.client();
 		}
 	}
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/config/AbstractReactiveMongoConfigurationIntegrationTests.java

@@ -25,6 +25,7 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.core.ReactiveMongoOperations;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 
@@ -56,7 +57,7 @@ public class AbstractReactiveMongoConfigurationIntegrationTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/config/AbstractReactiveMongoConfigurationUnitTests.java

@@ -38,6 +38,7 @@ import org.springframework.data.mongodb.core.convert.MongoTypeMapper;
 import org.springframework.data.mongodb.core.mapping.BasicMongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.spel.EvaluationContextProvider;
 import org.springframework.data.spel.ExtensionAwareEvaluationContextProvider;
 import org.springframework.test.util.ReflectionTestUtils;
@@ -155,7 +156,7 @@ public class AbstractReactiveMongoConfigurationUnitTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Bean
@@ -183,7 +184,7 @@ public class AbstractReactiveMongoConfigurationUnitTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/config/ReactiveAuditingTests.java

@@ -38,6 +38,7 @@ import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
 import org.springframework.data.mongodb.repository.config.EnableReactiveMongoRepositories;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 
@@ -70,7 +71,7 @@ public class ReactiveAuditingTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Bean

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

@@ -69,11 +69,6 @@ public class ClientSessionTests {
 		template.getDb().getCollection(COLLECTION_NAME).insertOne(new Document("_id", "id-1").append("value", "spring"));
 	}
 
-	@After
-	public void tearDown() {
-		client.close();
-	}
-
 	@Test // DATAMONGO-1880
 	public void shouldApplyClientSession() {
 

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

@@ -39,6 +39,7 @@ import org.springframework.data.mongodb.core.index.IndexInfo;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Collation.CaseFirst;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.util.Version;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@@ -60,7 +61,7 @@ public class DefaultReactiveIndexOperationsTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

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

@@ -33,6 +33,7 @@ import org.junit.Test;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.mongodb.test.util.MongoVersionRule;
 import org.springframework.data.util.Version;
 
@@ -50,13 +51,13 @@ public class JsonSchemaQueryTests {
 
 	public static @ClassRule MongoVersionRule REQUIRES_AT_LEAST_3_6_0 = MongoVersionRule.atLeast(Version.parse("3.6.0"));
 
-	static MongoClient client = MongoClients.create();
+	static MongoClient client = MongoTestUtils.client();
 	MongoTemplate template;
 	Person jellyBelly, roseSpringHeart, kazmardBoombub;
 
 	@BeforeClass
 	public static void beforeClass() {
-		 client = MongoClients.create();
+		client = MongoTestUtils.client();
 	}
 
 	@Before
@@ -93,13 +94,6 @@ public class JsonSchemaQueryTests {
 		template.save(kazmardBoombub);
 	}
 
-	@AfterClass
-	public static void afterClass() {
-		if (client != null) {
-			client.close();
-		}
-	}
-
 	@Test // DATAMONGO-1835
 	public void findsDocumentsWithRequiredFieldsCorrectly() {
 
@@ -114,12 +108,10 @@ public class JsonSchemaQueryTests {
 
 		MongoJsonSchema schema = MongoJsonSchema.builder().required("address").build();
 
-		com.mongodb.reactivestreams.client.MongoClient mongoClient = com.mongodb.reactivestreams.client.MongoClients.create();
+		com.mongodb.reactivestreams.client.MongoClient mongoClient = MongoTestUtils.reactiveClient();
 
 		new ReactiveMongoTemplate(mongoClient, DATABASE_NAME).find(query(matchingDocumentStructure(schema)), Person.class)
 				.as(StepVerifier::create).expectNextCount(2).verifyComplete();
-
-		mongoClient.close();
 	}
 
 	@Test // DATAMONGO-1835

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

@@ -76,7 +76,7 @@ public class ReactiveFindOperationSupportTests {
 
 		insertObjects();
 
-		template = new ReactiveMongoTemplate(MongoClients.create(), "ExecutableFindOperationSupportTests");
+		template = new ReactiveMongoTemplate(MongoTestUtils.reactiveClient(), "ExecutableFindOperationSupportTests");
 	}
 
 	void insertObjects() {

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

@@ -28,17 +28,18 @@ import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.config.AbstractReactiveMongoConfiguration;
 import org.springframework.data.mongodb.core.query.Collation;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.mongodb.test.util.MongoVersionRule;
 import org.springframework.data.util.Version;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 import com.mongodb.reactivestreams.client.MongoClient;
-import com.mongodb.reactivestreams.client.MongoClients;
 
 /**
  * @author Mark Paluch
@@ -56,7 +57,7 @@ public class ReactiveMongoTemplateCollationTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override
@@ -98,10 +99,9 @@ public class ReactiveMongoTemplateCollationTests {
 
 		return template.execute(db -> {
 
-			return Flux
-					.from(db.runCommand(new Document() //
-							.append("listCollections", 1) //
-							.append("filter", new Document("name", collectionName)))) //
+			return Flux.from(db.runCommand(new Document() //
+					.append("listCollections", 1) //
+					.append("filter", new Document("name", collectionName)))) //
 					.map(it -> it.get("cursor", Document.class))
 					.flatMapIterable(it -> (List<Document>) it.get("firstBatch", List.class));
 		}).next();

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

@@ -62,7 +62,7 @@ public class ReactiveRemoveOperationSupportTests {
 		blocking.save(han);
 		blocking.save(luke);
 
-		template = new ReactiveMongoTemplate(MongoClients.create(), "ExecutableRemoveOperationSupportTests");
+		template = new ReactiveMongoTemplate(MongoTestUtils.reactiveClient(), "ExecutableRemoveOperationSupportTests");
 	}
 
 	@Test // DATAMONGO-1719

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

@@ -65,7 +65,7 @@ public class ReactiveUpdateOperationSupportTests {
 		blocking.save(han);
 		blocking.save(luke);
 
-		template = new ReactiveMongoTemplate(MongoClients.create(), "ExecutableUpdateOperationSupportTests");
+		template = new ReactiveMongoTemplate(MongoTestUtils.reactiveClient(), "ExecutableUpdateOperationSupportTests");
 	}
 
 	@Test // DATAMONGO-1719

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

@@ -149,7 +149,6 @@ public class SessionBoundMongoTemplateTests {
 	public void tearDown() {
 
 		session.close();
-		client.close();
 	}
 
 	@Test // DATAMONGO-1880

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

@@ -60,7 +60,7 @@ public class ReactiveMongoTemplateAuditingTests {
 		@Bean
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

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

@@ -35,6 +35,7 @@ import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.SimpleMongoClientDbFactory;
 import org.springframework.data.mongodb.core.mapping.DBRef;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 
 import com.mongodb.client.MongoClient;
 import com.mongodb.client.MongoClients;
@@ -55,7 +56,7 @@ public class MappingMongoConverterTests {
 	@Before
 	public void setUp() {
 
-		client = MongoClients.create();
+		client = MongoTestUtils.client();
 		client.getDatabase("mapping-converter-tests").drop();
 
 		MongoDbFactory factory = new SimpleMongoClientDbFactory(client, "mapping-converter-tests");

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/event/ApplicationContextEventTests.java

@@ -46,6 +46,7 @@ import org.springframework.data.mongodb.repository.QPerson;
 import org.springframework.data.mongodb.repository.query.MongoEntityInformation;
 import org.springframework.data.mongodb.repository.support.MongoRepositoryFactory;
 import org.springframework.data.mongodb.repository.support.QuerydslMongoPredicateExecutor;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 
 import com.mongodb.WriteConcern;
 import com.mongodb.client.MongoClient;
@@ -75,12 +76,7 @@ public class ApplicationContextEventTests {
 
 	@BeforeClass
 	public static void beforeClass() {
-		mongo = MongoClients.create();
-	}
-
-	@AfterClass
-	public static void afterClass() {
-		mongo.close();
+		mongo = MongoTestUtils.client();
 	}
 
 	@Before

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

@@ -32,6 +32,7 @@ import org.junit.Test;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.util.Base64Utils;
 
 import com.mongodb.client.MongoClient;
@@ -59,7 +60,7 @@ public class CriteriaTests {
 	@Before
 	public void setUp() {
 
-		client = MongoClients.create();
+		client = MongoTestUtils.client();
 		ops = new MongoTemplate(client, "criteria-tests");
 
 		ops.dropCollection(DocumentWithBitmask.class);

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

@@ -36,6 +36,7 @@ import org.springframework.data.mongodb.core.CollectionOptions;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.convert.MongoJsonSchemaMapper;
 import org.springframework.data.mongodb.core.mapping.Field;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.mongodb.test.util.MongoVersionRule;
 import org.springframework.data.util.Version;
 import org.springframework.test.context.ContextConfiguration;
@@ -60,7 +61,7 @@ public class ReactiveMongoJsonSchemaTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

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

@@ -67,7 +67,6 @@ import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 import com.mongodb.reactivestreams.client.MongoClient;
-import com.mongodb.reactivestreams.client.MongoClients;
 
 /**
  * Test for {@link ReactiveMongoRepository} query methods.
@@ -94,7 +93,7 @@ public class ReactiveMongoRepositoryTests {
 		@Bean
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override
@@ -133,11 +132,10 @@ public class ReactiveMongoRepositoryTests {
 	@BeforeClass
 	public static void cleanDb() {
 
-		try (MongoClient client = MongoClients.create()) {
+		MongoClient client = MongoTestUtils.reactiveClient();
 
-			MongoTestUtils.createOrReplaceCollectionNow("reactive", "person", client);
-			MongoTestUtils.createOrReplaceCollectionNow("reactive", "capped", client);
-		}
+		MongoTestUtils.createOrReplaceCollectionNow("reactive", "person", client);
+		MongoTestUtils.createOrReplaceCollectionNow("reactive", "capped", client);
 	}
 
 	@Before

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

@@ -25,6 +25,7 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.repository.ReactivePersonRepository;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -45,7 +46,8 @@ public class ReactiveMongoRepositoriesRegistrarIntegrationTests {
 
 		@Bean
 		public ReactiveMongoTemplate reactiveMongoTemplate() throws Exception {
-			return new ReactiveMongoTemplate(new SimpleReactiveMongoDatabaseFactory(MongoClients.create(), "database"));
+			return new ReactiveMongoTemplate(
+					new SimpleReactiveMongoDatabaseFactory(MongoTestUtils.reactiveClient(), "database"));
 		}
 	}
 

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

@@ -78,7 +78,7 @@ public class ReactiveQuerydslMongoPredicateExecutorTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override
@@ -90,11 +90,10 @@ public class ReactiveQuerydslMongoPredicateExecutorTests {
 	@BeforeClass
 	public static void cleanDb() {
 
-		try (MongoClient client = MongoClients.create()) {
+		MongoClient client = MongoTestUtils.reactiveClient();
 
-			MongoTestUtils.createOrReplaceCollectionNow("reactive", "person", client);
-			MongoTestUtils.createOrReplaceCollectionNow("reactive", "user", client);
-		}
+		MongoTestUtils.createOrReplaceCollectionNow("reactive", "person", client);
+		MongoTestUtils.createOrReplaceCollectionNow("reactive", "user", client);
 	}
 
 	@Before

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

@@ -33,6 +33,7 @@ import org.springframework.data.mongodb.core.mapping.BasicMongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.repository.VersionedPerson;
 import org.springframework.data.mongodb.repository.query.MongoEntityInformation;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.data.mongodb.test.util.MongoVersion;
 import org.springframework.data.mongodb.test.util.ReplicaSet;
 import org.springframework.data.util.ClassTypeInformation;
@@ -56,7 +57,7 @@ public class SimpleMongoRepositoryVersionedEntityTests {
 
 		@Override
 		public MongoClient mongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.client();
 		}
 
 		@Override

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

@@ -31,6 +31,7 @@ import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.repository.VersionedPerson;
 import org.springframework.data.mongodb.repository.query.MongoEntityInformation;
+import org.springframework.data.mongodb.test.util.MongoTestUtils;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -49,7 +50,7 @@ public class SimpleReactiveMongoRepositoryVersionedEntityTests {
 
 		@Override
 		public MongoClient reactiveMongoClient() {
-			return MongoClients.create();
+			return MongoTestUtils.reactiveClient();
 		}
 
 		@Override

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/test/util/CleanMongoDB.java

@@ -361,14 +361,13 @@ public class CleanMongoDB implements TestRule {
 
 			boolean isInternal = false;
 			if (client == null) {
-				client = MongoClients.create();
+				client = MongoTestUtils.client();
 				isInternal = true;
 			}
 
 			doClean();
 
 			if (isInternal) {
-				client.close();
 				client = null;
 			}
 		}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/test/util/MongoTestUtils.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.mongodb.test.util;
 
-import com.mongodb.client.MongoClient;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
@@ -25,20 +24,29 @@ import org.bson.Document;
 
 import com.mongodb.ReadPreference;
 import com.mongodb.WriteConcern;
+import com.mongodb.client.MongoClient;
 import com.mongodb.client.MongoCollection;
 import com.mongodb.client.MongoDatabase;
 import com.mongodb.reactivestreams.client.MongoClients;
 import com.mongodb.reactivestreams.client.Success;
 
 /**
+ * Utility to create (and reuse) imperative and reactive {@code MongoClient} instances.
+ *
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 public class MongoTestUtils {
 
+	public static final String CONNECTION_STRING = "mongodb://localhost:27017/?replicaSet=rs0"; // &readPreference=primary&w=majority
 
 	private static final String CONNECTION_STRING_PATTERN = "mongodb://%s:%s/";
-	public static final String CONNECTION_STRING = "mongodb://localhost:27017/?replicaSet=rs0"; // &readPreference=primary&w=majority
 
+	/**
+	 * Create a new {@link com.mongodb.client.MongoClient} with defaults.
+	 *
+	 * @return new instance of {@link com.mongodb.client.MongoClient}.
+	 */
 	public static MongoClient client() {
 		return client("localhost", 27017);
 	}
@@ -46,6 +54,20 @@ public class MongoTestUtils {
 	public static MongoClient client(String host, int port) {
 		return com.mongodb.client.MongoClients.create(String.format(CONNECTION_STRING_PATTERN, host, port));
 	}
+
+	/**
+	 * Create a new {@link com.mongodb.reactivestreams.client.MongoClient} with defaults.
+	 *
+	 * @return new instance of {@link com.mongodb.reactivestreams.client.MongoClient}.
+	 */
+	public static com.mongodb.reactivestreams.client.MongoClient reactiveClient() {
+		return reactiveClient("localhost", 27017);
+	}
+
+	public static com.mongodb.reactivestreams.client.MongoClient reactiveClient(String host, int port) {
+		return MongoClients.create(String.format(CONNECTION_STRING_PATTERN, host, port));
+	}
+
 	/**
 	 * Create a {@link com.mongodb.client.MongoCollection} if it does not exist, or drop and recreate it if it does.
 	 *

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/test/util/MongoVersionRule.java

@@ -178,7 +178,6 @@ public class MongoVersionRule implements TestRule {
 			MongoClient client = MongoTestUtils.client(host, port);
 			MongoDatabase database = client.getDatabase("test");
 			Document result = database.runCommand(new Document("buildInfo", 1));
-			client.close();
 
 			return Version.parse(result.get("version", String.class));
 		} catch (Exception e) {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/test/util/ReplicaSet.java

@@ -94,12 +94,11 @@ public class ReplicaSet implements TestRule {
 
 		if (runsAsReplicaSet.get() == null) {
 
-			try (MongoClient client = MongoTestUtils.client()) {
+			MongoClient client = MongoTestUtils.client();
 
-				boolean tmp = client.getDatabase("admin").runCommand(new Document("getCmdLineOpts", "1"))
-						.get("argv", List.class).contains("--replSet");
-				runsAsReplicaSet.compareAndSet(null, tmp);
-			}
+			boolean tmp = client.getDatabase("admin").runCommand(new Document("getCmdLineOpts", "1")).get("argv", List.class)
+					.contains("--replSet");
+			runsAsReplicaSet.compareAndSet(null, tmp);
 		}
 		return runsAsReplicaSet.get();
 	}