Harmonize mongo auto-configuration

Provides a way to easily exclude `MongoAutoConfiguration` or
`MongoReactiveAutoConfiguration` so that multiple mongo clients
are not present.

Fixes gh-12407

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfiguration.java

@@ -16,30 +16,25 @@
 
 package org.springframework.boot.autoconfigure.data.mongo;
 
-import java.util.Collections;
-
 import com.mongodb.ClientSessionOptions;
 import com.mongodb.DB;
 import com.mongodb.MongoClient;
 import com.mongodb.client.ClientSession;
 import com.mongodb.client.MongoDatabase;
 
-import org.springframework.beans.BeanUtils;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.boot.autoconfigure.domain.EntityScanner;
 import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.MongoProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
-import org.springframework.data.annotation.Persistent;
-import org.springframework.data.mapping.model.FieldNamingStrategy;
 import org.springframework.data.mongodb.MongoDbFactory;
 import org.springframework.data.mongodb.core.MongoTemplate;
 import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
@@ -48,7 +43,6 @@ import org.springframework.data.mongodb.core.convert.DefaultDbRefResolver;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
-import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.gridfs.GridFsTemplate;
 import org.springframework.util.Assert;
@@ -73,17 +67,15 @@ import org.springframework.util.StringUtils;
  */
 @Configuration
 @ConditionalOnClass({ MongoClient.class, MongoTemplate.class })
+@ConditionalOnBean(MongoClient.class)
 @EnableConfigurationProperties(MongoProperties.class)
+@Import(MongoDataConfiguration.class)
 @AutoConfigureAfter(MongoAutoConfiguration.class)
 public class MongoDataAutoConfiguration {
 
-	private final ApplicationContext applicationContext;
-
 	private final MongoProperties properties;
 
-	public MongoDataAutoConfiguration(ApplicationContext applicationContext,
-			MongoProperties properties) {
-		this.applicationContext = applicationContext;
+	public MongoDataAutoConfiguration(MongoProperties properties) {
 		this.properties = properties;
 	}
 
@@ -112,22 +104,6 @@ public class MongoDataAutoConfiguration {
 		return mappingConverter;
 	}
 
-	@Bean
-	@ConditionalOnMissingBean
-	public MongoMappingContext mongoMappingContext(MongoCustomConversions conversions)
-			throws ClassNotFoundException {
-		MongoMappingContext context = new MongoMappingContext();
-		context.setInitialEntitySet(new EntityScanner(this.applicationContext)
-				.scan(Document.class, Persistent.class));
-		Class<?> strategyClass = this.properties.getFieldNamingStrategy();
-		if (strategyClass != null) {
-			context.setFieldNamingStrategy(
-					(FieldNamingStrategy) BeanUtils.instantiateClass(strategyClass));
-		}
-		context.setSimpleTypeHolder(conversions.getSimpleTypeHolder());
-		return context;
-	}
-
 	@Bean
 	@ConditionalOnMissingBean
 	public GridFsTemplate gridFsTemplate(MongoDbFactory mongoDbFactory,
@@ -137,12 +113,6 @@ public class MongoDataAutoConfiguration {
 				mongoTemplate.getConverter());
 	}
 
-	@Bean
-	@ConditionalOnMissingBean
-	public MongoCustomConversions mongoCustomConversions() {
-		return new MongoCustomConversions(Collections.emptyList());
-	}
-
 	/**
 	 * {@link MongoDbFactory} decorator to respect
 	 * {@link MongoProperties#getGridFsDatabase()} if set.

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataConfiguration.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012-2018 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
+ *
+ *      http://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.boot.autoconfigure.data.mongo;
+
+import java.util.Collections;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.domain.EntityScanner;
+import org.springframework.boot.autoconfigure.mongo.MongoProperties;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.annotation.Persistent;
+import org.springframework.data.mapping.model.FieldNamingStrategy;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
+import org.springframework.data.mongodb.core.mapping.Document;
+import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+
+/**
+ * Base configuration class for Spring Data's mongo support.
+ *
+ * @author Madhura Bhave
+ */
+@Configuration
+class MongoDataConfiguration {
+
+	private final ApplicationContext applicationContext;
+
+	private final MongoProperties properties;
+
+	MongoDataConfiguration(ApplicationContext applicationContext,
+			MongoProperties properties) {
+		this.applicationContext = applicationContext;
+		this.properties = properties;
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public MongoMappingContext mongoMappingContext(MongoCustomConversions conversions)
+			throws ClassNotFoundException {
+		MongoMappingContext context = new MongoMappingContext();
+		context.setInitialEntitySet(new EntityScanner(this.applicationContext)
+				.scan(Document.class, Persistent.class));
+		Class<?> strategyClass = this.properties.getFieldNamingStrategy();
+		if (strategyClass != null) {
+			context.setFieldNamingStrategy(
+					(FieldNamingStrategy) BeanUtils.instantiateClass(strategyClass));
+		}
+		context.setSimpleTypeHolder(conversions.getSimpleTypeHolder());
+		return context;
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public MongoCustomConversions mongoCustomConversions() {
+		return new MongoCustomConversions(Collections.emptyList());
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfiguration.java

@@ -20,6 +20,7 @@ import com.mongodb.reactivestreams.client.MongoClient;
 
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.mongo.MongoProperties;
@@ -27,10 +28,15 @@ import org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfigurati
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 import org.springframework.data.mongodb.ReactiveMongoDatabaseFactory;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.data.mongodb.core.SimpleReactiveMongoDatabaseFactory;
+import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
+import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
+import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for Spring Data's reactive mongo
@@ -47,9 +53,10 @@ import org.springframework.data.mongodb.core.convert.MongoConverter;
  */
 @Configuration
 @ConditionalOnClass({ MongoClient.class, ReactiveMongoTemplate.class })
+@ConditionalOnBean(MongoClient.class)
 @EnableConfigurationProperties(MongoProperties.class)
-@AutoConfigureAfter({ MongoReactiveAutoConfiguration.class,
-		MongoDataAutoConfiguration.class })
+@Import(MongoDataConfiguration.class)
+@AutoConfigureAfter(MongoReactiveAutoConfiguration.class)
 public class MongoReactiveDataAutoConfiguration {
 
 	private final MongoProperties properties;
@@ -74,4 +81,14 @@ public class MongoReactiveDataAutoConfiguration {
 		return new ReactiveMongoTemplate(reactiveMongoDatabaseFactory, converter);
 	}
 
+	@Bean
+	@ConditionalOnMissingBean(MongoConverter.class)
+	public MappingMongoConverter mappingMongoConverter(MongoMappingContext context,
+			MongoCustomConversions conversions) {
+		MappingMongoConverter mappingConverter = new MappingMongoConverter(
+				NoOpDbRefResolver.INSTANCE, context);
+		mappingConverter.setCustomConversions(conversions);
+		return mappingConverter;
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoReactiveAutoConfiguration.java

@@ -24,6 +24,7 @@ import com.mongodb.async.client.MongoClientSettings;
 import com.mongodb.connection.netty.NettyStreamFactoryFactory;
 import com.mongodb.reactivestreams.client.MongoClient;
 import io.netty.channel.socket.SocketChannel;
+import reactor.core.publisher.Flux;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -44,7 +45,7 @@ import org.springframework.core.env.Environment;
  * @since 2.0.0
  */
 @Configuration
-@ConditionalOnClass(MongoClient.class)
+@ConditionalOnClass({ MongoClient.class, Flux.class })
 @EnableConfigurationProperties(MongoProperties.class)
 public class MongoReactiveAutoConfiguration {
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoDataAutoConfigurationTests.java

@@ -22,9 +22,12 @@ import java.util.Set;
 
 import com.mongodb.MongoClient;
 import org.junit.After;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 
 import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.autoconfigure.AutoConfigurationPackages;
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.autoconfigure.data.mongo.city.City;
@@ -60,6 +63,9 @@ public class MongoDataAutoConfigurationTests {
 
 	private AnnotationConfigApplicationContext context;
 
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
 	@After
 	public void close() {
 		if (this.context != null) {
@@ -162,6 +168,15 @@ public class MongoDataAutoConfigurationTests {
 		assertThat(dateProperty.isEntity()).isFalse();
 	}
 
+	@Test
+	public void backsOffIfMongoClientBeanIsNotPresent() {
+		this.context = new AnnotationConfigApplicationContext();
+		this.context.register(MongoDataAutoConfiguration.class);
+		this.context.refresh();
+		this.thrown.expect(NoSuchBeanDefinitionException.class);
+		assertThat(this.context.getBean(MongoDataAutoConfiguration.class)).isNull();
+	}
+
 	public void testFieldNamingStrategy(String strategy,
 			Class<? extends FieldNamingStrategy> expectedType) {
 		this.context = new AnnotationConfigApplicationContext();

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/mongo/MongoReactiveDataAutoConfigurationTests.java

@@ -17,10 +17,12 @@
 package org.springframework.boot.autoconfigure.data.mongo;
 
 import org.junit.After;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
-import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
@@ -36,6 +38,9 @@ public class MongoReactiveDataAutoConfigurationTests {
 
 	private AnnotationConfigApplicationContext context;
 
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
 	@After
 	public void close() {
 		if (this.context != null) {
@@ -46,11 +51,20 @@ public class MongoReactiveDataAutoConfigurationTests {
 	@Test
 	public void templateExists() {
 		this.context = new AnnotationConfigApplicationContext(
-				PropertyPlaceholderAutoConfiguration.class, MongoAutoConfiguration.class,
-				MongoDataAutoConfiguration.class, MongoReactiveAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class,
+				MongoReactiveAutoConfiguration.class,
 				MongoReactiveDataAutoConfiguration.class);
 		assertThat(this.context.getBeanNamesForType(ReactiveMongoTemplate.class))
 				.hasSize(1);
 	}
 
+	@Test
+	public void backsOffIfMongoClientBeanIsNotPresent() {
+		this.context = new AnnotationConfigApplicationContext(
+				PropertyPlaceholderAutoConfiguration.class,
+				MongoReactiveDataAutoConfiguration.class);
+		this.thrown.expect(NoSuchBeanDefinitionException.class);
+		this.context.getBean(MongoReactiveDataAutoConfiguration.class);
+	}
+
 }