DATAKV-121 - Added support for projections on repository query methods.

Repository methods can now return interfaces that act as projections on the original entity instances stored in the repository.

Related ticket: DATACMNS-89.

src/test/java/org/springframework/data/keyvalue/core/SpelQueryEngineUnitTests.java

@@ -35,6 +35,7 @@ import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
 import org.springframework.data.keyvalue.repository.query.SpelQueryCreator;
+import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.query.ParametersParameterAccessor;
 import org.springframework.data.repository.query.QueryMethod;
@@ -100,11 +101,12 @@ public class SpelQueryEngineUnitTests {
 		}
 
 		Method method = PersonRepository.class.getMethod(methodName, types.toArray(new Class<?>[types.size()]));
-
 		RepositoryMetadata metadata = mock(RepositoryMetadata.class);
+		doReturn(method.getReturnType()).when(metadata).getReturnedDomainClass(method);
+
 		PartTree partTree = new PartTree(method.getName(), method.getReturnType());
-		SpelQueryCreator creator = new SpelQueryCreator(partTree,
-				new ParametersParameterAccessor(new QueryMethod(method, metadata).getParameters(), args));
+		SpelQueryCreator creator = new SpelQueryCreator(partTree, new ParametersParameterAccessor(
+				new QueryMethod(method, metadata, new SpelAwareProxyProjectionFactory()).getParameters(), args));
 
 		KeyValueQuery<SpelExpression> query = creator.createQuery();
 		query.getCritieria().setEvaluationContext(new StandardEvaluationContext(args));

src/test/java/org/springframework/data/keyvalue/repository/query/SpelQueryCreatorUnitTests.java

@@ -17,6 +17,7 @@ package org.springframework.data.keyvalue.repository.query;
 
 import static org.hamcrest.core.Is.*;
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
 
 import java.lang.reflect.Method;
 import java.util.Date;
@@ -30,6 +31,7 @@ import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
+import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.query.ParametersParameterAccessor;
 import org.springframework.data.repository.query.QueryMethod;
@@ -238,7 +240,7 @@ public class SpelQueryCreatorUnitTests {
 	 * @see DATACMNS-525
 	 */
 	@Test
-	public void greaterThanEaualsReturnsTrueForEqualValues() throws Exception {
+	public void greaterThanEqualsReturnsTrueForEqualValues() throws Exception {
 		assertThat(evaluate("findByAgeGreaterThanEqual", BRAN.age).against(BRAN), is(true));
 	}
 
@@ -394,10 +396,11 @@ public class SpelQueryCreatorUnitTests {
 		}
 
 		Method method = PersonRepository.class.getMethod(methodName, argTypes);
+		doReturn(Person.class).when(metadataMock).getReturnedDomainClass(method);
 
 		PartTree partTree = new PartTree(method.getName(), method.getReturnType());
-		SpelQueryCreator creator = new SpelQueryCreator(partTree, new ParametersParameterAccessor(new QueryMethod(method,
-				metadataMock).getParameters(), args));
+		SpelQueryCreator creator = new SpelQueryCreator(partTree, new ParametersParameterAccessor(
+				new QueryMethod(method, metadataMock, new SpelAwareProxyProjectionFactory()).getParameters(), args));
 
 		KeyValueQuery<SpelExpression> q = creator.createQuery();
 		q.getCritieria().setEvaluationContext(new StandardEvaluationContext(args));

src/test/java/org/springframework/data/map/AbstractRepositoryUnitTests.java

@@ -155,6 +155,34 @@ public abstract class AbstractRepositoryUnitTests<T extends AbstractRepositoryUn
 		assertThat(result, contains(TYRION, JAIME, CERSEI));
 	}
 
+	/**
+	 * @see DATAKV-121
+	 */
+	@Test
+	public void projectsResultToInterface() {
+
+		repository.save(LENNISTERS);
+
+		List<PersonSummary> result = repository.findByAgeGreaterThan(0, new Sort("firstname"));
+
+		assertThat(result, hasSize(3));
+		assertThat(result.get(0).getFirstname(), is(CERSEI.getFirstname()));
+	}
+
+	/**
+	 * @see DATAKV-121
+	 */
+	@Test
+	public void projectsResultToDynamicInterface() {
+
+		repository.save(LENNISTERS);
+
+		List<PersonSummary> result = repository.findByAgeGreaterThan(0, new Sort("firstname"), PersonSummary.class);
+
+		assertThat(result, hasSize(3));
+		assertThat(result.get(0).getFirstname(), is(CERSEI.getFirstname()));
+	}
+
 	protected abstract T getRepository(KeyValueRepositoryFactory factory);
 
 	public static interface PersonRepository extends CrudRepository<Person, String>, KeyValueRepository<Person, String> {
@@ -173,6 +201,13 @@ public abstract class AbstractRepositoryUnitTests<T extends AbstractRepositoryUn
 
 		List<Person> findByAgeGreaterThanOrderByAgeAscFirstnameDesc(int age);
 
+		List<PersonSummary> findByAgeGreaterThan(int age, Sort sort);
+
+		<T> List<T> findByAgeGreaterThan(int age, Sort sort, Class<T> projectionType);
 	}
 
+	interface PersonSummary {
+
+		String getFirstname();
+	}
 }