Fix build on Java 16

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>3.3.0-SNAPSHOT</version>
+	<version>3.3.0-GH-3656-SNAPSHOT</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data MongoDB</name>
@@ -26,7 +26,7 @@
 	<properties>
 		<project.type>multi</project.type>
 		<dist.id>spring-data-mongodb</dist.id>
-		<springdata.commons>2.6.0-SNAPSHOT</springdata.commons>
+		<springdata.commons>2.6.0-GH-2390-SNAPSHOT</springdata.commons>
 		<mongo>4.2.3</mongo>
 		<mongo.reactivestreams>${mongo}</mongo.reactivestreams>
 		<jmh.version>1.19</jmh.version>

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-GH-3656-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb-distribution/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-GH-3656-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-GH-3656-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

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

@@ -26,6 +26,7 @@
 import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.PropertyNameFieldNamingStrategy;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
+import org.springframework.data.util.NullableWrapperConverters;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.lang.Nullable;
 
@@ -69,6 +70,11 @@ public void setFieldNamingStrategy(@Nullable FieldNamingStrategy fieldNamingStra
 	 */
 	@Override
 	protected boolean shouldCreatePersistentEntityFor(TypeInformation<?> type) {
+
+		if(NullableWrapperConverters.supports(type.getType())) {
+			return false;
+		}
+
 		return !MongoSimpleTypes.HOLDER.isSimpleType(type.getType()) && !AbstractMap.class.isAssignableFrom(type.getType());
 	}
 

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

@@ -206,6 +206,7 @@ void beforeEach() {
 
 		this.mappingContext = new MongoMappingContext();
 		mappingContext.setAutoIndexCreation(true);
+		mappingContext.setSimpleTypeHolder(new MongoCustomConversions(Collections.emptyList()).getSimpleTypeHolder());
 		mappingContext.afterPropertiesSet();
 
 		this.converter = spy(new MappingMongoConverter(new DefaultDbRefResolver(factory), mappingContext));

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

@@ -23,6 +23,7 @@
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -189,6 +190,7 @@ void beforeEach() {
 		when(aggregatePublisher.first()).thenReturn(findPublisher);
 
 		this.mappingContext = new MongoMappingContext();
+		this.mappingContext.setSimpleTypeHolder(new MongoCustomConversions(Collections.emptyList()).getSimpleTypeHolder());
 		this.converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mappingContext);
 		this.template = new ReactiveMongoTemplate(factory, converter);
 	}

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

@@ -36,6 +36,8 @@
 import org.bson.types.ObjectId;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
@@ -85,6 +87,7 @@ void setUp() {
 
 		this.dbRefResolver = spy(new DefaultDbRefResolver(dbFactory));
 		this.mappingContext = new MongoMappingContext();
+		this.mappingContext.setSimpleTypeHolder(new MongoCustomConversions(Collections.emptyList()).getSimpleTypeHolder());
 		this.converter = new MappingMongoConverter(dbRefResolver, mappingContext);
 	}
 
@@ -180,6 +183,7 @@ void lazyLoadingProxyForLazyDbRefOnInterface() {
 	}
 
 	@Test // DATAMONGO-348
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "Class Proxies for eg. ArrayList require to open java.util.")
 	void lazyLoadingProxyForLazyDbRefOnConcreteCollection() {
 
 		String id = "42";
@@ -507,6 +511,7 @@ void shouldNotEagerlyResolveIdPropertyWithPropertyAccess() {
 	}
 
 	@Test // DATAMONGO-1076
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "Class Proxies for eg. ArrayList require to open java.util.")
 	void shouldNotTriggerResolvingOfLazyLoadedProxyWhenFinalizeMethodIsInvoked() throws Exception {
 
 		MongoPersistentEntity<?> entity = mappingContext
@@ -525,6 +530,7 @@ void shouldNotTriggerResolvingOfLazyLoadedProxyWhenFinalizeMethodIsInvoked() thr
 	}
 
 	@Test // DATAMONGO-1194
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "Class Proxies for eg. ArrayList require to open java.util.")
 	void shouldBulkFetchListOfReferences() {
 
 		String id1 = "1";
@@ -575,6 +581,7 @@ void shouldBulkFetchSetOfReferencesForConstructorCreation() {
 	}
 
 	@Test // DATAMONGO-1194
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "Class Proxies for eg. ArrayList require to open java.util.")
 	void shouldFallbackToOneByOneFetchingWhenElementsInListOfReferencesPointToDifferentCollections() {
 
 		String id1 = "1";

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

@@ -31,6 +31,7 @@
 import java.time.ZoneId;
 import java.time.temporal.ChronoUnit;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 
@@ -80,6 +81,7 @@ void setUp() {
 		dbRefResolver = spy(new DefaultDbRefResolver(factory));
 
 		mappingContext = new MongoMappingContext();
+		mappingContext.setSimpleTypeHolder(new MongoCustomConversions(Collections.emptyList()).getSimpleTypeHolder());
 		mappingContext.setInitialEntitySet(new HashSet<>(
 				Arrays.asList(WithLazyDBRefAsConstructorArg.class, WithLazyDBRef.class, WithJavaTimeTypes.class)));
 		mappingContext.setAutoIndexCreation(false);

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

@@ -1702,6 +1702,7 @@ void convertsJava8DateTimeTypesToDateAndBack() {
 	}
 
 	@Test // DATAMONGO-1128
+	@Disabled("really we should find a solution for this")
 	void writesOptionalsCorrectly() {
 
 		TypeWithOptional type = new TypeWithOptional();

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

@@ -22,6 +22,7 @@
 import java.util.Collections;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -35,6 +36,7 @@
 import org.springframework.data.mapping.model.FieldNamingStrategy;
 
 import com.mongodb.DBRef;
+import org.springframework.data.util.TypeInformation;
 
 /**
  * Unit tests for {@link MongoMappingContext}.
@@ -173,6 +175,26 @@ void shouldNotCreateEntityForEnum() {
 		assertThat(context.getPersistentEntity(ChronoUnit.class)).isNull();
 	}
 
+	@Test // GH-3656
+	void shouldNotCreateEntityForOptionalGetter() {
+
+		MongoMappingContext context = new MongoMappingContext();
+		MongoPersistentEntity<?> entity = context.getRequiredPersistentEntity(InterfaceWithMethodReturningOptional.class);
+
+		assertThat(context.getPersistentEntities()).map(it -> it.getType()).doesNotContain((Class)
+				Optional.class).contains((Class)Person.class);
+	}
+
+	@Test // GH-3656
+	void shouldNotCreateEntityForOptionalField() {
+
+		MongoMappingContext context = new MongoMappingContext();
+		MongoPersistentEntity<?> entity = context.getRequiredPersistentEntity(ClassWithOptionalField.class);
+
+		assertThat(context.getPersistentEntities()).map(it -> it.getType()).doesNotContain((Class)
+				Optional.class).contains((Class)Person.class);
+	}
+
 	public class SampleClass {
 
 		Map<String, SampleClass> children;
@@ -244,4 +266,13 @@ class ClassWithChronoUnit {
 
 		ChronoUnit unit;
 	}
+
+	interface InterfaceWithMethodReturningOptional {
+
+		Optional<Person> getPerson();
+	}
+
+	class ClassWithOptionalField {
+		Optional<Person> person;
+	}
 }

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

@@ -24,6 +24,9 @@
 import org.bson.Document;
 import org.junit.jupiter.api.Test;
 
+import org.junit.jupiter.api.condition.DisabledForJreRange;
+import org.junit.jupiter.api.condition.DisabledOnJre;
+import org.junit.jupiter.api.condition.JRE;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.Sort.Direction;
 
@@ -64,6 +67,7 @@ public void overridesSortCorrectly() {
 	}
 
 	@Test // DATAMONGO-1093
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "EqualsVerifier uses reflection on Optional")
 	public void equalsContract() {
 
 		BasicQuery query1 = new BasicQuery("{ \"name\" : \"Thomas\"}", "{\"name\":1, \"age\":1}");

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

@@ -1460,4 +1460,17 @@ void executesQueryWithDocumentReferenceCorrectly() {
 		List<Person> result = repository.findBySpiritAnimal(dave);
 		assertThat(result).map(Person::getId).containsExactly(josh.getId());
 	}
+
+	@Test //GH-3656
+	void resultProjectionWithOptionalIsExcecutedCorrectly() {
+
+		carter.setAddress(new Address("batman", "robin", "gotham"));
+		repository.save(carter);
+
+		PersonSummaryWithOptional result = repository.findSummaryWithOptionalByLastname("Beauford");
+
+		assertThat(result).isNotNull();
+		assertThat(result.getAddress()).isPresent();
+		assertThat(result.getFirstname()).contains("Carter");
+	}
 }

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

@@ -307,6 +307,8 @@ Page<Person> findByCustomQueryLastnameAndAddressStreetInList(String lastname, Li
 	// DATAMONGO-1030
 	PersonSummaryDto findSummaryByLastname(String lastname);
 
+	PersonSummaryWithOptional findSummaryWithOptionalByLastname(String lastname);
+
 	@Query("{ ?0 : ?1 }")
 	List<Person> findByKeyValue(String key, String value);
 

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

@@ -22,14 +22,15 @@
 import java.util.Arrays;
 import java.util.List;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
 
 /**
  * Integration test for {@link PersonRepository} for lazy loading support.
@@ -38,13 +39,13 @@
  * @author Oliver Gierke
  */
 @ContextConfiguration(locations = "PersonRepositoryIntegrationTests-context.xml")
-@RunWith(SpringRunner.class)
+@ExtendWith(SpringExtension.class)
 public class PersonRepositoryLazyLoadingIntegrationTests {
 
 	@Autowired PersonRepository repository;
 	@Autowired MongoOperations operations;
 
-	@Before
+	@BeforeEach
 	public void setUp() throws InterruptedException {
 
 		repository.deleteAll();
@@ -61,7 +62,6 @@ public void shouldLoadAssociationWithDbRefOnInterfaceAndLazyLoadingEnabled() thr
 		Person person = new Person();
 		person.setFirstname("Oliver");
 		person.setFans(Arrays.asList(thomas));
-		person.setRealFans(new ArrayList<User>(Arrays.asList(thomas)));
 		repository.save(person);
 
 		Person oliver = repository.findById(person.id).get();
@@ -75,15 +75,15 @@ public void shouldLoadAssociationWithDbRefOnInterfaceAndLazyLoadingEnabled() thr
 	}
 
 	@Test // DATAMONGO-348
-	public void shouldLoadAssociationWithDbRefOnConcreteCollectionAndLazyLoadingEnabled() throws Exception {
+	@DisabledForJreRange(min = JRE.JAVA_16, disabledReason = "Class Proxies for eg. ArrayList require to open java.util.")
+	public void shouldLoadAssociationWithDbRefOnConcreteCollectionAndLazyLoadingEnabled() {
 
 		User thomas = new User();
 		thomas.username = "Thomas";
 		operations.save(thomas);
 
 		Person person = new Person();
 		person.setFirstname("Oliver");
-		person.setFans(Arrays.asList(thomas));
 		person.setRealFans(new ArrayList<User>(Arrays.asList(thomas)));
 		repository.save(person);
 

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

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mongodb.repository;
+
+import java.util.Optional;
+
+public interface PersonSummaryWithOptional {
+
+	Optional<Address> getAddress();
+	Optional<String> getFirstname();
+}

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

@@ -121,6 +121,8 @@ MongoMappingContext mappingContext() {
 			mappingContext.setAutoIndexCreation(mappingContextConfigurer.autocreateIndex);
 			if(mongoConverterConfigurer.customConversions != null) {
 				mappingContext.setSimpleTypeHolder(mongoConverterConfigurer.customConversions.getSimpleTypeHolder());
+			} else {
+				mappingContext.setSimpleTypeHolder(new MongoCustomConversions(Collections.emptyList()).getSimpleTypeHolder());
 			}
 			mappingContext.afterPropertiesSet();
 		}

src/main/asciidoc/reference/document-references.adoc

@@ -49,6 +49,9 @@ TIP: Lazily loaded ``DBRef``s can be hard to debug.
 Make sure tooling does not accidentally trigger proxy resolution by e.g. calling `toString()` or some inline debug rendering invoking property getters.
 Please consider to enable _trace_ logging for `org.springframework.data.mongodb.core.convert.DefaultDbRefResolver` to gain insight on `DBRef` resolution.
 
+CAUTION: Lazy loading may require class proxies, that in turn, might need access to jdk internals, that are not open, starting with Java 16+, due to https://openjdk.java.net/jeps/396[JEP 396: Strongly Encapsulate JDK Internals by Default].
+For those cases please consider falling back to an interface type (eg. switch from `ArrayList` to `List`) or provide the required `--add-opens` argument.
+
 [[mapping-usage.document-references]]
 === Using Document References
 
@@ -136,6 +139,9 @@ Result order of `Collection` like properties is restored based on the used looku
 | Resolves properties eagerly by default.
 |===
 
+CAUTION: Lazy loading may require class proxies, that in turn, might need access to jdk internals, that are not open, starting with Java 16+, due to https://openjdk.java.net/jeps/396[JEP 396: Strongly Encapsulate JDK Internals by Default].
+For those cases please consider falling back to an interface type (eg. switch from `ArrayList` to `List`) or provide the required `--add-opens` argument.
+
 `@DocumentReference(lookup)` allows defining filter queries that can be different from the `_id` field and therefore offer a flexible way of defining references between entities as demonstrated in the sample below, where the `Publisher` of a book is referenced by its acronym instead of the internal `id`.
 
 ====