From 7673567a8c9affbbdd9a21b4b857347551055bbd Mon Sep 17 00:00:00 2001
From: Oliver Gierke <info@olivergierke.de>
Date: Wed, 16 May 2012 14:27:53 +0200
Subject: [PATCH] DATACMNS-171 - Added isQueryForEntity() method to
 QueryMethod.

isQueryForEntity() returns true if the QueryMethod returns either a single entity, a collection or Page of those.
---
 .../data/repository/query/QueryMethod.java    | 26 ++++++++----
 .../query/QueryMethodUnitTests.java           | 40 +++++++++++++++++++
 2 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/QueryMethod.java b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/QueryMethod.java
index 57f179894..a1afaf5fc 100644
--- a/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/QueryMethod.java
+++ b/spring-data-commons-core/src/main/java/org/springframework/data/repository/query/QueryMethod.java
@@ -123,7 +123,7 @@ public class QueryMethod {
 	/**
 	 * Returns the domain class the query method is targeted at.
 	 * 
-	 * @return
+	 * @return will never be {@literal null}.
 	 */
 	protected Class<?> getDomainClass() {
 
@@ -165,29 +165,39 @@ public class QueryMethod {
 		return org.springframework.util.ClassUtils.isAssignable(Page.class, returnType);
 	}
 
+	/**
+	 * Returns whether the query method is a modifying one.
+	 * 
+	 * @return
+	 */
 	public boolean isModifyingQuery() {
-
 		return false;
 	}
 
+	/**
+	 * Returns whether the query for theis method actually returns entities.
+	 * 
+	 * @return
+	 */
+	public boolean isQueryForEntity() {
+		return getDomainClass().isAssignableFrom(getReturnedObjectType());
+	}
+
 	/**
 	 * Returns the {@link Parameters} wrapper to gain additional information about {@link Method} parameters.
 	 * 
 	 * @return
 	 */
 	public Parameters getParameters() {
-
 		return parameters;
 	}
 
 	/*
-			 * (non-Javadoc)
-			 *
-			 * @see java.lang.Object#toString()
-			 */
+	 * (non-Javadoc)
+	 * @see java.lang.Object#toString()
+	 */
 	@Override
 	public String toString() {
-
 		return method.toString();
 	}
 }
diff --git a/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/QueryMethodUnitTests.java b/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/QueryMethodUnitTests.java
index f77f462ff..5375477c9 100644
--- a/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/QueryMethodUnitTests.java
+++ b/spring-data-commons-core/src/test/java/org/springframework/data/repository/query/QueryMethodUnitTests.java
@@ -16,6 +16,7 @@
 package org.springframework.data.repository.query;
 
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
 import static org.hamcrest.CoreMatchers.*;
 
 import java.lang.reflect.Method;
@@ -23,6 +24,7 @@ import java.lang.reflect.Method;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -73,6 +75,32 @@ public class QueryMethodUnitTests {
 		assertThat(queryMethod.isCollectionQuery(), is(false));
 	}
 
+	@Test
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	public void detectsAnEntityBeingReturned() throws Exception {
+
+		when(metadata.getDomainType()).thenReturn((Class) User.class);
+		when(metadata.getReturnedDomainClass(Mockito.any(Method.class))).thenReturn((Class) SpecialUser.class);
+
+		Method method = SampleRepository.class.getMethod("returnsEntitySubclass");
+		QueryMethod queryMethod = new QueryMethod(method, metadata);
+
+		assertThat(queryMethod.isQueryForEntity(), is(true));
+	}
+
+	@Test
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	public void detectsNonEntityBeingReturned() throws Exception {
+
+		when(metadata.getDomainType()).thenReturn((Class) User.class);
+		when(metadata.getReturnedDomainClass(Mockito.any(Method.class))).thenReturn((Class) Integer.class);
+
+		Method method = SampleRepository.class.getMethod("returnsProjection");
+		QueryMethod queryMethod = new QueryMethod(method, metadata);
+
+		assertThat(queryMethod.isQueryForEntity(), is(false));
+	}
+
 	interface SampleRepository {
 		String pagingMethodWithInvalidReturnType(Pageable pageable);
 
@@ -83,5 +111,17 @@ public class QueryMethodUnitTests {
 		Iterable<String> sampleMethod();
 
 		Page<String> anotherSampleMethod(Pageable pageable);
+
+		SpecialUser returnsEntitySubclass();
+
+		Integer returnsProjection();
+	}
+
+	class User {
+
+	}
+
+	class SpecialUser extends User {
+
 	}
 }