DATACMNS-1008 - Reintroduced lost support for non-generic redeclarations of generic CRUD methods.

The changes for DATACMNS-854 and DATACMNS-912 dropped the support for the simpler redeclaration of generic methods like CrudRepository.save(…) which as of the changes requires to be redeclared like <T extends Foo> T save(T entity). Previously a simple redeclaration like Foo save(Foo entity) was sufficient.

This commit reintroduces the check for a direct match of the parameter types and shortcuts the more detailed check that's necessary in case of type variables being involved.

Related tickets: DATACMNS-854, DATACMNS-912.

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

@@ -372,6 +372,10 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 				continue;
 			}
 
+			if (types[i].equals(parameterType)) {
+				continue;
+			}
+
 			if (!type.isAssignableFrom(parameterType) || !type.equals(methodParameterTypes[i])) {
 				return false;
 			}

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

@@ -223,12 +223,12 @@ public class DefaultRepositoryInformationUnitTests {
 	@Test // DATACMNS-912
 	public void discoversCustomlyImplementedCrudMethodWithGenericParameters() throws Exception {
 
-		SampleRepositoryImpl customImplementation = new SampleRepositoryImpl();
-		RepositoryMetadata metadata = new DefaultRepositoryMetadata(SampleRepository.class);
+		GenericsSaveRepositoryImpl customImplementation = new GenericsSaveRepositoryImpl();
+		RepositoryMetadata metadata = new DefaultRepositoryMetadata(GenericsSaveRepository.class);
 		RepositoryInformation information = new DefaultRepositoryInformation(metadata, RepositoryFactorySupport.class,
 				customImplementation.getClass());
 
-		Method customBaseRepositoryMethod = SampleRepository.class.getMethod("save", Object.class);
+		Method customBaseRepositoryMethod = GenericsSaveRepository.class.getMethod("save", Object.class);
 		assertThat(information.isCustomMethod(customBaseRepositoryMethod), is(true));
 	}
 
@@ -244,6 +244,18 @@ public class DefaultRepositoryInformationUnitTests {
 				is(DummyRepositoryImpl.class.getMethod("save", Iterable.class)));
 	}
 
+	@Test // DATACMNS-1008, DATACMNS-912, DATACMNS-854
+	public void discoversCustomlyImplementedCrudMethodWithoutGenericParameters() throws Exception {
+
+		SimpleSaveRepositoryImpl customImplementation = new SimpleSaveRepositoryImpl();
+		RepositoryMetadata metadata = new DefaultRepositoryMetadata(SimpleSaveRepository.class);
+		RepositoryInformation information = new DefaultRepositoryInformation(metadata, RepositoryFactorySupport.class,
+				customImplementation.getClass());
+
+		Method customBaseRepositoryMethod = SimpleSaveRepository.class.getMethod("save", Object.class);
+		assertThat(information.isCustomMethod(customBaseRepositoryMethod), is(true));
+	}
+
 	private static Method getMethodFrom(Class<?> type, String name) {
 
 		for (Method method : type.getMethods()) {
@@ -346,11 +358,13 @@ public class DefaultRepositoryInformationUnitTests {
 		List<User> findAll();
 	}
 
-	interface SampleRepository extends CrudRepository<Sample, Long> {}
+	// DATACMNS-854, DATACMNS-912
+
+	interface GenericsSaveRepository extends CrudRepository<Sample, Long> {}
 
-	static class SampleRepositoryImpl {
+	static class GenericsSaveRepositoryImpl {
 
-		public <S extends Sample> S save(S entity) {
+		public <T extends Sample> T save(T entity) {
 			return entity;
 		}
 	}
@@ -367,4 +381,15 @@ public class DefaultRepositoryInformationUnitTests {
 
 		private @Delegate CrudRepository<T, ID> delegate;
 	}
+
+	// DATACMNS-1008, DATACMNS-854, DATACMNS-912
+
+	interface SimpleSaveRepository extends CrudRepository<Sample, Long> {}
+
+	static class SimpleSaveRepositoryImpl {
+
+		public Sample save(Sample entity) {
+			return entity;
+		}
+	}
 }