DATACMNS-854 - Allow custom implementation of repository methods with generics.

Add additional check for detecting customized method where method contains generics. Overriding methods without generics already works, this patch simply makes the behavior consistent.

Original pull request: #162.

src/main/java/org/springframework/data/repository/core/support/DefaultRepositoryInformation.java

@@ -356,7 +356,10 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 					return false;
 				}
 			} else {
-				if (!types[i].equals(parameterType)) {
+				// We must either have an exact match, or,
+				if (!types[i].equals(parameterType) &&
+						// the tpes must be assignable _and_ signature definition types must be identical.
+						!(types[i].isAssignableFrom(parameterType) && types[i].equals(method.getParameterTypes()[i]))) {
 					return false;
 				}
 			}

src/test/java/org/springframework/data/repository/core/support/DefaultRepositoryInformationUnitTests.java

@@ -94,6 +94,22 @@ public class DefaultRepositoryInformationUnitTests {
 		assertThat(information.getTargetClassMethod(source), is(expected));
 	}
 
+	/**
+	 * @see DATACMNS-854
+	 */
+	@Test
+	public void discoversCustomlyImplementedCrudMethodWithGenerics() throws SecurityException, NoSuchMethodException {
+
+		RepositoryMetadata metadata = new DefaultRepositoryMetadata(FooRepository.class);
+		RepositoryInformation information = new DefaultRepositoryInformation(metadata, CrudRepository.class,
+			customImplementation.getClass());
+
+		Method source = FooRepositoryCustom.class.getMethod("exists", Object.class);
+		Method expected = customImplementation.getClass().getMethod("exists", Object.class);
+
+		assertThat(information.getTargetClassMethod(source), is(expected));
+	}
+
 	@Test
 	public void considersIntermediateMethodsAsFinderMethods() {
 
@@ -248,8 +264,11 @@ public class DefaultRepositoryInformationUnitTests {
 		User findOne(Long primaryKey);
 	}
 
-	interface FooRepositoryCustom {
+	interface FooSuperInterfaceWithGenerics<T> {
+		boolean exists(T id);
+	}
 
+	interface FooRepositoryCustom extends FooSuperInterfaceWithGenerics<User> {
 		User save(User user);
 	}