DATACMNS-836 - Polishing.

RepositoryMetadata now exposes an ….isReactiveRepository() that's implemented by inspecting the backing repository interface for any reactive wrapper type appearing in method signatures. That allows us to move down the use of a ConversionService down to ReactiveRepositoryInformation.WrapperConversionMatch.

Made a couple of methods static that could be. Simplified some logic using streams. A bit better wording in assertions. Some formatting when using streams.

src/main/java/org/springframework/data/util/ReflectionUtils.java

@@ -20,6 +20,7 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.util.Arrays;
 import java.util.stream.Stream;
 
 import org.springframework.beans.BeanUtils;
@@ -264,6 +265,23 @@ public abstract class ReflectionUtils {
 		return null;
 	}
 
+	/**
+	 * Returns a {@link Stream} of the return and parameters types of the given {@link Method}.
+	 * 
+	 * @param method must not be {@literal null}.
+	 * @return
+	 * @since 2.0
+	 */
+	public static Stream<Class<?>> returnTypeAndParameters(Method method) {
+
+		Assert.notNull(method, "Method must not be null!");
+
+		Stream<Class<?>> returnType = Stream.of(method.getReturnType());
+		Stream<Class<?>> parameterTypes = Arrays.stream(method.getParameterTypes());
+
+		return Stream.concat(returnType, parameterTypes);
+	}
+
 	private static final boolean argumentsMatch(Class<?>[] parameterTypes, Object[] arguments) {
 
 		if (parameterTypes.length != arguments.length) {

src/main/java/org/springframework/data/util/StreamUtils.java

@@ -51,8 +51,8 @@ public class StreamUtils {
 		Spliterator<T> spliterator = Spliterators.spliteratorUnknownSize(iterator, Spliterator.NONNULL);
 		Stream<T> stream = StreamSupport.stream(spliterator, false);
 
-		return iterator instanceof CloseableIterator ? stream.onClose(new CloseableIteratorDisposingRunnable(
-				(CloseableIterator<T>) iterator)) : stream;
+		return iterator instanceof CloseableIterator
+				? stream.onClose(new CloseableIteratorDisposingRunnable((CloseableIterator<T>) iterator)) : stream;
 	}
 
 	/**