DATAJPA-45 - ClassUtils.getReturnedDomainClass works for parameterized component types of Collections and Page.

spring-data-commons-core/src/main/java/org/springframework/data/repository/util/ClassUtils.java

@@ -22,8 +22,11 @@ import java.lang.reflect.Type;
 import java.util.Arrays;
 import java.util.Collection;
 
+import org.springframework.core.GenericTypeResolver;
 import org.springframework.data.domain.Page;
 import org.springframework.data.repository.Repository;
+import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.TypeInformation;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 
@@ -53,18 +56,19 @@ public abstract class ClassUtils {
      */
     public static Class<?> getReturnedDomainClass(Method method) {
 
-        Class<?> returnType = method.getReturnType();
+        Class<?> type = method.getReturnType();
 
-        if (Collection.class.isAssignableFrom(returnType)
-                || Page.class.isAssignableFrom(returnType)) {
+        if (Collection.class.isAssignableFrom(type)
+                || Page.class.isAssignableFrom(type)) {
 
-            Type type = method.getGenericReturnType();
-
-            return (Class<?>) ((ParameterizedType) type)
-                    .getActualTypeArguments()[0];
+            ParameterizedType returnType = (ParameterizedType) method.getGenericReturnType();
+            Type componentType = returnType.getActualTypeArguments()[0];
+            
+            return componentType instanceof ParameterizedType ? (Class<?>) ((ParameterizedType) componentType).getRawType()
+                : (Class<?>) componentType;
         }
 
-        return returnType;
+        return type;
     }
 
 

spring-data-commons-core/src/test/java/org/springframework/data/repository/util/ClassUtilsUnitTests.java

@@ -15,10 +15,13 @@
  */
 package org.springframework.data.repository.util;
 
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 import static org.springframework.data.repository.util.ClassUtils.*;
 
 import java.io.Serializable;
+import java.util.List;
+import java.util.Map;
 
 import org.junit.Test;
 import org.springframework.data.domain.Page;
@@ -59,6 +62,11 @@ public class ClassUtilsUnitTests {
         assertTrue(hasProperty(User.class, "Firstname"));
         assertFalse(hasProperty(User.class, "address"));
     }
+    
+    @Test
+    public void handlesGenericTypeInReturnedCollectionCorrectly() throws SecurityException, NoSuchMethodException {
+        assertEquals(Map.class, getReturnedDomainClass(SomeDao.class.getMethod("anotherMethod")));
+    }
 
     @SuppressWarnings("unused")
     private class User {
@@ -93,6 +101,9 @@ public class ClassUtilsUnitTests {
 
 
         GenericType<User> someMethod();
+        
+        
+        List<Map<String, Object>> anotherMethod();
     }
 
     private class GenericType<T> {