DATAMONGO-1752 - Fixed execution of repository query methods with closed projections.

We now skip the explicit definition of which type to read in case a closed projection is defined as return type.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/AbstractMongoQuery.java

@@ -86,8 +86,11 @@ public abstract class AbstractMongoQuery implements RepositoryQuery {
 		applyQueryMetaAttributesWhenPresent(query);
 
 		ResultProcessor processor = method.getResultProcessor().withDynamicProjection(accessor);
-		ReturnedType returnedType = processor.getReturnedType();
-		FindWithQuery<?> find = findOperationWithProjection.as(returnedType.getTypeToRead());
+		Class<?> typeToRead = processor.getReturnedType().getTypeToRead();
+
+		FindWithQuery<?> find = typeToRead == null //
+				? findOperationWithProjection //
+				: findOperationWithProjection.as(typeToRead);
 
 		MongoQueryExecution execution = getExecution(accessor, find);
 

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

@@ -16,8 +16,10 @@
 package org.springframework.data.mongodb.repository;
 
 import static java.util.Arrays.*;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertThat;
 import static org.springframework.data.geo.Metrics.*;
 
 import java.util.ArrayList;
@@ -928,7 +930,7 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 	@Test // DATAMONGO-1030
 	public void executesSingleEntityQueryWithProjectionCorrectly() {
 
-		PersonSummary result = repository.findSummaryByLastname("Beauford");
+		PersonSummaryDto result = repository.findSummaryByLastname("Beauford");
 
 		assertThat(result, is(notNullValue()));
 		assertThat(result.firstname, is("Carter"));
@@ -1165,4 +1167,14 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 
 		assertThat(repository.countByThePersonsFirstname("Dave"), is(0L));
 	}
+
+	@Test // DATAMONGO-1752
+	public void readsOpenProjection() {
+		assertThat(repository.findOpenProjectionBy()).isNotEmpty();
+	}
+
+	@Test // DATAMONGO-1752
+	public void readsClosedProjection() {
+		assertThat(repository.findClosedProjectionBy()).isNotEmpty();
+	}
 }

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

@@ -0,0 +1,27 @@
+/*
+ * Copyright 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.data.mongodb.repository;
+
+import org.springframework.beans.factory.annotation.Value;
+
+/**
+ * @author Oliver Gierke
+ */
+public interface PersonExcerpt {
+
+	@Value("#{target.firstname + ' ' + target.lastname}")
+	String getFullName();
+}

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

@@ -286,7 +286,7 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	Page<Person> findTop3ByLastnameStartingWith(String lastname, Pageable pageRequest);
 
 	// DATAMONGO-1030
-	PersonSummary findSummaryByLastname(String lastname);
+	PersonSummaryDto findSummaryByLastname(String lastname);
 
 	@Query("{ ?0 : ?1 }")
 	List<Person> findByKeyValue(String key, String value);
@@ -325,4 +325,10 @@ public interface PersonRepository extends MongoRepository<Person, String>, Query
 	 */
 	@DeleteQuery("{ 'firstname' : ?0 }") // DATAMONGO-1539
 	void deleteByThePersonsFirstname(String firstname);
+
+	// DATAMONGO-1752
+	Iterable<PersonExcerpt> findOpenProjectionBy();
+
+	// DATAMONGO-1752
+	Iterable<PersonSummary> findClosedProjectionBy();
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 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.
@@ -18,8 +18,9 @@ package org.springframework.data.mongodb.repository;
 /**
  * @author Oliver Gierke
  */
-public class PersonSummary {
+public interface PersonSummary {
 
-	String firstname;
-	String lastname;
+	String getFirstname();
+
+	String getLastname();
 }

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

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2014 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.data.mongodb.repository;
+
+/**
+ * @author Oliver Gierke
+ */
+public class PersonSummaryDto {
+
+	String firstname;
+	String lastname;
+}