DATACMNS-715 - Repository factory now adds TransactionProxy interface if available.

We now leniently add the TransactionProxy marker interface to the repository proxy to opt-out of any further transaction handling potentially applied through @EnableTransactionManagement or its XML equivalent.

The interface will be introduced in Spring 4.1.7 / 4.2 RC2 so we're reflectively adding it if present. Might be something we can think of making less indirect for Fowler once 4.1.7 has been released.

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

@@ -59,6 +59,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware {
 
 	private static final boolean IS_JAVA_8 = org.springframework.util.ClassUtils.isPresent("java.util.Optional",
 			RepositoryFactorySupport.class.getClassLoader());
+	private static final Class<?> TRANSACTION_PROXY_TYPE = getTransactionProxyType();
 
 	private final Map<RepositoryInformationCacheKey, RepositoryInformation> repositoryInformationCache = new HashMap<RepositoryInformationCacheKey, RepositoryInformation>();
 	private final List<RepositoryProxyPostProcessor> postProcessors = new ArrayList<RepositoryProxyPostProcessor>();
@@ -174,6 +175,10 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware {
 		result.setTarget(target);
 		result.setInterfaces(new Class[] { repositoryInterface, Repository.class });
 
+		if (TRANSACTION_PROXY_TYPE != null) {
+			result.addInterface(TRANSACTION_PROXY_TYPE);
+		}
+
 		for (RepositoryProxyPostProcessor processor : postProcessors) {
 			processor.postProcess(result, information);
 		}
@@ -296,6 +301,21 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware {
 
 	}
 
+	/**
+	 * Returns the TransactionProxy type or {@literal null} if not on the classpath.
+	 * 
+	 * @return
+	 */
+	private static Class<?> getTransactionProxyType() {
+
+		try {
+			return org.springframework.util.ClassUtils
+					.forName("org.springframework.transaction.interceptor.TransactionalProxy", null);
+		} catch (ClassNotFoundException o_O) {
+			return null;
+		}
+	}
+
 	/**
 	 * This {@code MethodInterceptor} intercepts calls to methods of the custom implementation and delegates the to it if
 	 * configured. Furthermore it resolves method calls to finders and triggers execution of them. You can rely on having

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

@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.Set;
 import java.util.concurrent.Future;
 
+import org.junit.Assume;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -80,9 +81,8 @@ public class RepositoryFactorySupportUnitTests {
 
 		Mockito.reset(factory.strategy);
 
-		when(
-				factory.strategy.resolveQuery(Mockito.any(Method.class), Mockito.any(RepositoryMetadata.class),
-						Mockito.any(NamedQueries.class))).thenReturn(factory.queryOne, factory.queryTwo);
+		when(factory.strategy.resolveQuery(Mockito.any(Method.class), Mockito.any(RepositoryMetadata.class),
+				Mockito.any(NamedQueries.class))).thenReturn(factory.queryOne, factory.queryTwo);
 
 		factory.addQueryCreationListener(listener);
 		factory.addQueryCreationListener(otherListener);
@@ -223,6 +223,26 @@ public class RepositoryFactorySupportUnitTests {
 		factory.addRepositoryProxyPostProcessor(null);
 	}
 
+	/**
+	 * @see DATACMNS-715, SPR-13109
+	 */
+	@Test
+	public void addsTransactionProxyInterfaceIfAvailable() throws Exception {
+
+		try {
+
+			Class<?> type = ClassUtils.forName("org.springframework.transaction.interceptor.TransactionalProxy", null);
+
+			SimpleRepository repository = factory.getRepository(SimpleRepository.class);
+			assertThat(repository, is(instanceOf(type)));
+
+		} catch (ClassNotFoundException o_O) {
+			Assume.assumeFalse(true);
+		}
+	}
+
+	interface SimpleRepository extends Repository<Object, Serializable> {}
+
 	interface ObjectRepository extends Repository<Object, Serializable>, ObjectRepositoryCustom {
 
 		Object findByClass(Class<?> clazz);