Merge pull request #7600 from michael-simons:DataMongoTest

* pr/7600:
  Polish contribution
  Add slide test annotation for MongoDB

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -100,7 +100,7 @@ public class SessionAutoConfigurationTests extends AbstractSessionAutoConfigurat
 	public void mongoSessionStore() {
 		load(Arrays.asList(EmbeddedMongoAutoConfiguration.class,
 				MongoAutoConfiguration.class, MongoDataAutoConfiguration.class),
-				"spring.session.store-type=mongo", "spring.data.mongodb.port=0");
+				"spring.session.store-type=mongo");
 		validateSessionRepository(MongoOperationsSessionRepository.class);
 	}
 
@@ -108,7 +108,7 @@ public class SessionAutoConfigurationTests extends AbstractSessionAutoConfigurat
 	public void mongoSessionStoreWithCustomizations() {
 		load(Arrays.asList(EmbeddedMongoAutoConfiguration.class,
 				MongoAutoConfiguration.class, MongoDataAutoConfiguration.class),
-				"spring.session.store-type=mongo", "spring.data.mongodb.port=0",
+				"spring.session.store-type=mongo",
 				"spring.session.mongo.collection-name=foobar");
 		MongoOperationsSessionRepository repository = validateSessionRepository(
 				MongoOperationsSessionRepository.class);

spring-boot-docs/src/main/asciidoc/index.adoc

@@ -1,5 +1,5 @@
 = Spring Boot Reference Guide
-Phillip Webb; Dave Syer; Josh Long; Stéphane Nicoll; Rob Winch; Andy Wilkinson; Marcel Overdijk; Christian Dupuis; Sébastien Deleuze
+Phillip Webb; Dave Syer; Josh Long; Stéphane Nicoll; Rob Winch; Andy Wilkinson; Marcel Overdijk; Christian Dupuis; Sébastien Deleuze; Michael Simons
 :doctype: book
 :toc:
 :toclevels: 4

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -5685,6 +5685,55 @@ A list of the auto-configuration that is enabled by `@JdbcTest` can be
 
 
 
+[[boot-features-testing-spring-boot-applications-testing-autoconfigured-mongo-test]]
+==== Auto-configured Data MongoDB tests
+`@DataMongoTest` can be used if you want to test MongoDB applications. By default, it will
+configure an in-memory embedded MongoDB (if available), configure a `MongoTemplate`, scan
+for `@Document` classes and configure Spring Data MongoDB repositories. Regular
+`@Component` beans will not be loaded into the `ApplicationContext`:
+
+[source,java,indent=0]
+----
+	import org.junit.runner.RunWith;
+	import org.springframework.beans.factory.annotation.Autowired;
+	import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
+	import org.springframework.data.mongodb.core.MongoTemplate;
+	import org.springframework.test.context.junit4.SpringRunner;
+
+	@RunWith(SpringRunner.class)
+	@DataMongoTest
+	public class ExampleDataMongoTests {
+
+		@Autowired
+		private MongoTemplate mongoTemplate;
+
+		//
+	}
+----
+
+In-memory embedded MongoDB generally works well for tests since it is fast and doesn't
+require any developer installation. If, however, you prefer to run tests against a real
+MongoDB server you should exclude the embedded mongodb auto-configuration:
+
+[source,java,indent=0]
+----
+	import org.junit.runner.RunWith;
+    import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration;
+	import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
+	import org.springframework.test.context.junit4.SpringRunner;
+
+	@RunWith(SpringRunner.class)
+	@DataMongoTest(excludeAutoConfiguration = EmbeddedMongoAutoConfiguration.class)
+	public class ExampleDataMongoNonEmbeddedTests {
+
+	}
+----
+
+A list of the auto-configuration that is enabled by `@DataMongoTest` can be
+<<appendix-test-auto-configuration#test-auto-configuration,found in the appendix>>.
+
+
+
 [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-client]]
 ==== Auto-configured REST clients
 The `@RestClientTest` annotation can be used if you want to test REST clients. By default

spring-boot-samples/spring-boot-sample-data-mongodb/src/main/java/sample/data/mongo/CustomerRepository.java

@@ -22,8 +22,8 @@ import org.springframework.data.mongodb.repository.MongoRepository;
 
 public interface CustomerRepository extends MongoRepository<Customer, String> {
 
-	public Customer findByFirstName(String firstName);
+	Customer findByFirstName(String firstName);
 
-	public List<Customer> findByLastName(String lastName);
+	List<Customer> findByLastName(String lastName);
 
 }

spring-boot-samples/spring-boot-sample-data-mongodb/src/main/resources/application.properties

@@ -1 +0,0 @@
-spring.data.mongodb.port=0

spring-boot-test-autoconfigure/pom.xml

@@ -106,6 +106,11 @@
 			</exclusions>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-mongodb</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.restdocs</groupId>
 			<artifactId>spring-restdocs-mockmvc</artifactId>
@@ -177,5 +182,10 @@
 			<artifactId>tomcat-embed-el</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>de.flapdoodle.embed</groupId>
+			<artifactId>de.flapdoodle.embed.mongo</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 </project>

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/data/mongo/AutoConfigureDataMongo.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2012-2017 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.test.autoconfigure.data.mongo;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+
+/**
+ * {@link ImportAutoConfiguration Auto-configuration imports} for typical Data MongoDB
+ * tests. Most tests should consider using {@link DataMongoTest @DataMongoTest} rather
+ * than using this annotation directly.
+ *
+ * @author Michael J. Simons
+ * @since 1.5.0
+ * @see DataMongoTest
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Inherited
+@ImportAutoConfiguration
+public @interface AutoConfigureDataMongo {
+}

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/data/mongo/DataMongoTest.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2012-2017 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.test.autoconfigure.data.mongo;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.test.autoconfigure.OverrideAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.core.AutoConfigureCache;
+import org.springframework.boot.test.autoconfigure.filter.TypeExcludeFilters;
+import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
+import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.test.context.BootstrapWith;
+
+/**
+ * Annotation that can be used in combination with {@code @RunWith(SpringRunner.class)}
+ * for a typical MongoDB test. Can be used when a test focuses
+ * <strong>only</strong> on MongoDB components.
+ * <p>
+ * Using this annotation will disable full auto-configuration and instead apply only
+ * configuration relevant to MongoDB tests.
+ * <p>
+ * By default, tests annotated with {@code @DataMongoTest} will use an embedded in-memory
+ * MongoDB process (if available).
+ *
+ * @author Michael J. Simons
+ * @author Stephane Nicoll
+ * @since 1.5.0
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Inherited
+@BootstrapWith(SpringBootTestContextBootstrapper.class)
+@OverrideAutoConfiguration(enabled = false)
+@TypeExcludeFilters(DataMongoTypeExcludeFilter.class)
+@AutoConfigureCache
+@AutoConfigureDataMongo
+@ImportAutoConfiguration
+public @interface DataMongoTest {
+
+	/**
+	 * Determines if default filtering should be used with
+	 * {@link SpringBootApplication @SpringBootApplication}. By default no beans
+	 * are included.
+	 *
+	 * @see #includeFilters()
+	 * @see #excludeFilters()
+	 * @return if default filters should be used
+	 */
+	boolean useDefaultFilters() default true;
+
+	/**
+	 * A set of include filters which can be used to add otherwise filtered
+	 * beans to the application context.
+	 *
+	 * @return include filters to apply
+	 */
+	Filter[] includeFilters() default {};
+
+	/**
+	 * A set of exclude filters which can be used to filter beans that would
+	 * otherwise be added to the application context.
+	 *
+	 * @return exclude filters to apply
+	 */
+	Filter[] excludeFilters() default {};
+
+	/**
+	 * Auto-configuration exclusions that should be applied for this test.
+	 * @return auto-configuration exclusions to apply
+	 */
+	@AliasFor(annotation = ImportAutoConfiguration.class, attribute = "exclude")
+	Class<?>[] excludeAutoConfiguration() default {};
+}

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/data/mongo/DataMongoTypeExcludeFilter.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Set;
+
+import org.springframework.boot.context.TypeExcludeFilter;
+import org.springframework.boot.test.autoconfigure.filter.AnnotationCustomizableTypeExcludeFilter;
+import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.core.annotation.AnnotatedElementUtils;
+import org.springframework.core.type.classreading.MetadataReader;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+
+/**
+ * {@link TypeExcludeFilter} for {@link DataMongoTest @DataMongoTest}.
+ *
+ * @author Michael J. Simons
+ */
+class DataMongoTypeExcludeFilter extends AnnotationCustomizableTypeExcludeFilter {
+
+	private final DataMongoTest annotation;
+
+	DataMongoTypeExcludeFilter(final Class<?> testClass) {
+		this.annotation = AnnotatedElementUtils.getMergedAnnotation(testClass,
+				DataMongoTest.class);
+	}
+
+	@Override
+	protected boolean hasAnnotation() {
+		return this.annotation != null;
+	}
+
+	@Override
+	protected Filter[] getFilters(final FilterType type) {
+		switch (type) {
+			case INCLUDE:
+				return this.annotation.includeFilters();
+			case EXCLUDE:
+				return this.annotation.excludeFilters();
+			default:
+				throw new IllegalStateException("Unsupported type " + type);
+		}
+	}
+
+	@Override
+	protected boolean isUseDefaultFilters() {
+		return this.annotation.useDefaultFilters();
+	}
+
+	@Override
+	protected boolean defaultInclude(final MetadataReader metadataReader,
+			final MetadataReaderFactory metadataReaderFactory) throws IOException {
+		return false;
+	}
+
+	@Override
+	protected Set<Class<?>> getDefaultIncludes() {
+		return Collections.emptySet();
+	}
+
+}

spring-boot-test-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -13,6 +13,13 @@ org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\
 org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\
 org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration
 
+# AutoConfigureDataMongo auto-configuration imports
+org.springframework.boot.test.autoconfigure.data.mongo.AutoConfigureDataMongo=\
+org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
+org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
+org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\
+org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration
+
 # AutoConfigureJdbc auto-configuration imports
 org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureJdbc=\
 org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\

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

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Sample test for {@link DataMongoTest @DataMongoTest}
+ *
+ * @author Michael J. Simons
+ */
+@RunWith(SpringRunner.class)
+@DataMongoTest
+public class DataMongoTestIntegrationTests {
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	@Autowired
+	private MongoTemplate mongoTemplate;
+
+	@Autowired
+	private ExampleRepository exampleRepository;
+
+	@Autowired
+	private ApplicationContext applicationContext;
+
+	@Test
+	public void testRepository() {
+		ExampleDocument exampleDocument = new ExampleDocument();
+		exampleDocument.setText("Look, new @DataMongoTest!");
+
+		exampleDocument = this.exampleRepository.save(exampleDocument);
+		assertThat(exampleDocument.getId()).isNotNull();
+
+		assertThat(this.mongoTemplate.collectionExists("exampleDocuments")).isTrue();
+	}
+
+	@Test
+	public void didNotInjectExampleController() {
+		this.thrown.expect(NoSuchBeanDefinitionException.class);
+		this.applicationContext.getBean(ExampleService.class);
+	}
+
+}

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

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.stereotype.Service;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration test with custom include filter for {@link DataMongoTest}.
+ *
+ * @author Michael J. Simons
+ */
+@RunWith(SpringRunner.class)
+@DataMongoTest(includeFilters = @Filter(Service.class))
+public class DataMongoTestWithIncludeFilterIntegrationTests {
+
+	@Autowired
+	private ExampleService service;
+
+	@Test
+	public void testRepository() {
+		assertThat(this.service.hasCollection("foobar")).isFalse();
+	}
+
+}

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

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import org.springframework.data.mongodb.core.mapping.Document;
+
+/**
+ * Example document used with {@link DataMongoTest} tests.
+ *
+ * @author Michael J. Simons
+ */
+@Document(collection = "exampleDocuments")
+public class ExampleDocument {
+
+	private String id;
+
+	private String text;
+
+	public String getId() {
+		return this.id;
+	}
+
+	public void setId(String id) {
+		this.id = id;
+	}
+
+	public String getText() {
+		return this.text;
+	}
+
+	public void setText(String text) {
+		this.text = text;
+	}
+
+}

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Example {@link SpringBootApplication} used with {@link DataMongoTest} tests.
+ *
+ * @author Michael J. Simons
+ */
+@SpringBootApplication
+public class ExampleMongoApplication {
+
+}

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

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2012-2016 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.test.autoconfigure.data.mongo;
+
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+/**
+ * Example repository used with {@link DataMongoTest} tests.
+ *
+ * @author Michael J. Simons
+ */
+public interface ExampleRepository extends MongoRepository<ExampleDocument, String> {
+}

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

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2012-2017 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.test.autoconfigure.data.mongo;
+
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.stereotype.Service;
+
+/**
+ * Example service used with {@link DataMongoTest} tests.
+ *
+ * @author Michael J. Simons
+ */
+@Service
+public class ExampleService {
+	private final MongoTemplate mongoTemplate;
+
+	public ExampleService(MongoTemplate mongoTemplate) {
+		this.mongoTemplate = mongoTemplate;
+	}
+
+	public boolean hasCollection(final String collectionName) {
+		return this.mongoTemplate.collectionExists(collectionName);
+	}
+
+}