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.

Author: odrotbohm

src/main/java/org/springframework/data/repository/core/RepositoryMetadata.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2015 the original author or authors.
+ * Copyright 2011-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -83,4 +83,12 @@ public interface RepositoryMetadata {
 	 * @since 1.11
 	 */
 	Set<Class<?>> getAlternativeDomainTypes();
+
+	/**
+	 * Returns whether the repository is a reactive one, i.e. if it uses reactive types in one of its methods.
+	 * 
+	 * @return
+	 * @since 2.0
+	 */
+	boolean isReactiveRepository();
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2015 the original author or authors.
+ * Copyright 2011-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@
 import org.springframework.data.repository.core.CrudMethods;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.util.QueryExecutionConverters;
+import org.springframework.data.repository.util.ReactiveWrappers;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.data.util.TypeInformation;
@@ -126,6 +127,15 @@ public Set<Class<?>> getAlternativeDomainTypes() {
 		return Collections.emptySet();
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.core.RepositoryMetadata#isReactiveRepository()
+	 */
+	@Override
+	public boolean isReactiveRepository() {
+		return ReactiveWrappers.usesReactiveType(repositoryInterface);
+	}
+
 	/**
 	 * Recursively unwraps well known wrapper types from the given {@link TypeInformation}.
 	 * 

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

@@ -47,11 +47,12 @@
  * 
  * @author Oliver Gierke
  * @author Thomas Darimont
+ * @author Mark Paluch
  */
 class DefaultRepositoryInformation implements RepositoryInformation {
 
-	@SuppressWarnings("rawtypes") private static final TypeVariable<Class<Repository>>[] PARAMETERS = Repository.class
-			.getTypeParameters();
+	@SuppressWarnings("rawtypes") //
+	private static final TypeVariable<Class<Repository>>[] PARAMETERS = Repository.class.getTypeParameters();
 	private static final String DOMAIN_TYPE_NAME = PARAMETERS[0].getName();
 	private static final String ID_TYPE_NAME = PARAMETERS[1].getName();
 
@@ -334,42 +335,13 @@ public Set<Class<?>> getAlternativeDomainTypes() {
 		return metadata.getAlternativeDomainTypes();
 	}
 
-	/**
-	 * Checks the given method's parameters to match the ones of the given base class method. Matches generic arguments
-	 * against the ones bound in the given repository interface.
-	 * 
-	 * @param method
-	 * @param baseClassMethod
-	 * @return
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.core.RepositoryMetadata#isReactiveRepository()
 	 */
-	private boolean parametersMatch(Method method, Method baseClassMethod) {
-
-		Class<?>[] methodParameterTypes = method.getParameterTypes();
-		Type[] genericTypes = baseClassMethod.getGenericParameterTypes();
-		Class<?>[] types = baseClassMethod.getParameterTypes();
-
-		for (int i = 0; i < genericTypes.length; i++) {
-
-			Type genericType = genericTypes[i];
-			Class<?> type = types[i];
-			MethodParameter parameter = new MethodParameter(method, i);
-			Class<?> parameterType = resolveParameterType(parameter, metadata.getRepositoryInterface());
-
-			if (genericType instanceof TypeVariable<?>) {
-
-				if (!matchesGenericType((TypeVariable<?>) genericType, ResolvableType.forMethodParameter(parameter))) {
-					return false;
-				}
-
-				continue;
-			}
-
-			if (!type.isAssignableFrom(parameterType) || !type.equals(methodParameterTypes[i])) {
-				return false;
-			}
-		}
-
-		return true;
+	@Override
+	public boolean isReactiveRepository() {
+		return metadata.isReactiveRepository();
 	}
 
 	/**
@@ -408,4 +380,42 @@ protected boolean matchesGenericType(TypeVariable<?> variable, ResolvableType pa
 
 		return false;
 	}
+
+	/**
+	 * Checks the given method's parameters to match the ones of the given base class method. Matches generic arguments
+	 * against the ones bound in the given repository interface.
+	 * 
+	 * @param method
+	 * @param baseClassMethod
+	 * @return
+	 */
+	private boolean parametersMatch(Method method, Method baseClassMethod) {
+
+		Class<?>[] methodParameterTypes = method.getParameterTypes();
+		Type[] genericTypes = baseClassMethod.getGenericParameterTypes();
+		Class<?>[] types = baseClassMethod.getParameterTypes();
+
+		for (int i = 0; i < genericTypes.length; i++) {
+
+			Type genericType = genericTypes[i];
+			Class<?> type = types[i];
+			MethodParameter parameter = new MethodParameter(method, i);
+			Class<?> parameterType = resolveParameterType(parameter, metadata.getRepositoryInterface());
+
+			if (genericType instanceof TypeVariable<?>) {
+
+				if (!matchesGenericType((TypeVariable<?>) genericType, ResolvableType.forMethodParameter(parameter))) {
+					return false;
+				}
+
+				continue;
+			}
+
+			if (!type.isAssignableFrom(parameterType) || !type.equals(methodParameterTypes[i])) {
+				return false;
+			}
+		}
+
+		return true;
+	}
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -72,14 +72,15 @@ public Object postProcessInvocationResult(Object result, TypeDescriptor returnTy
 
 			TypeDescriptor targetType = TypeDescriptor.valueOf(expectedReturnType);
 
-			if(conversionService.canConvert(WRAPPER_TYPE, returnTypeDescriptor)
-				&& !conversionService.canBypassConvert(WRAPPER_TYPE, targetType)) {
+			if (conversionService.canConvert(WRAPPER_TYPE, returnTypeDescriptor)
+					&& !conversionService.canBypassConvert(WRAPPER_TYPE, targetType)) {
 
 				return conversionService.convert(new NullableWrapper(result), expectedReturnType);
 			}
 
-			if(result != null && conversionService.canConvert(TypeDescriptor.valueOf(result.getClass()), returnTypeDescriptor)
-				&& !conversionService.canBypassConvert(TypeDescriptor.valueOf(result.getClass()), targetType)) {
+			if (result != null
+					&& conversionService.canConvert(TypeDescriptor.valueOf(result.getClass()), returnTypeDescriptor)
+					&& !conversionService.canBypassConvert(TypeDescriptor.valueOf(result.getClass()), targetType)) {
 
 				return conversionService.convert(result, expectedReturnType);
 			}