DATACMNS-867 - Second draft.

pom.xml

@@ -18,6 +18,7 @@
 	<properties>
 		<javaslang>2.0.4</javaslang>
 		<scala>2.11.7</scala>
+		<mockito>2.1.0-RC.1</mockito>
 		<xmlbeam>1.4.8</xmlbeam>
 	</properties>
 

src/main/java/org/springframework/data/auditing/AnnotationAuditingMetadata.java

@@ -60,7 +60,7 @@ final class AnnotationAuditingMetadata {
 
 	static {
 
-		List<String> types = new ArrayList<String>(5);
+		List<String> types = new ArrayList<>(5);
 		types.add("org.joda.time.DateTime");
 		types.add("org.joda.time.LocalDateTime");
 		types.add(Date.class.getName());

src/main/java/org/springframework/data/auditing/MappingAuditableBeanWrapperFactory.java

@@ -73,17 +73,16 @@ public class MappingAuditableBeanWrapperFactory extends DefaultAuditableBeanWrap
 			}
 
 			Class<?> type = it.getClass();
-			PersistentEntity<?, ?> entity = entities.getPersistentEntity(type);
 
-			if (entity == null) {
-				return super.getBeanWrapperFor(source);
-			}
+			return entities.getPersistentEntity(type).map(entity -> {
 
 				MappingAuditingMetadata metadata = metadataCache.computeIfAbsent(type,
-					foo -> new MappingAuditingMetadata(entity));
+						key -> new MappingAuditingMetadata(entity));
 
-			return Optional.ofNullable(metadata.isAuditable()
+				return Optional.<AuditableBeanWrapper>ofNullable(metadata.isAuditable()
 						? new MappingMetadataAuditableBeanWrapper(entity.getPropertyAccessor(it), metadata) : null);
+
+			}).orElseGet(() -> super.getBeanWrapperFor(source));
 		});
 	}
 

src/main/java/org/springframework/data/config/TypeFilterParser.java

@@ -85,7 +85,7 @@ public class TypeFilterParser {
 	public Collection<TypeFilter> parseTypeFilters(Element element, Type type) {
 
 		NodeList nodeList = element.getChildNodes();
-		Collection<TypeFilter> filters = new HashSet<TypeFilter>();
+		Collection<TypeFilter> filters = new HashSet<>();
 
 		for (int i = 0; i < nodeList.getLength(); i++) {
 

src/main/java/org/springframework/data/convert/ClassGeneratingEntityInstantiator.java

@@ -284,11 +284,8 @@ public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
 
 		private ObjectInstantiatorClassGenerator() {
 
-			this.classLoader = AccessController.doPrivileged(new PrivilegedAction<ByteArrayClassLoader>() {
-				public ByteArrayClassLoader run() {
-					return new ByteArrayClassLoader(ClassUtils.getDefaultClassLoader());
-				}
-			});
+			this.classLoader = AccessController.doPrivileged(
+					(PrivilegedAction<ByteArrayClassLoader>) () -> new ByteArrayClassLoader(ClassUtils.getDefaultClassLoader()));
 		}
 
 		/**

src/main/java/org/springframework/data/convert/ConfigurableTypeInformationMapper.java

@@ -18,7 +18,9 @@ package org.springframework.data.convert;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.util.ClassTypeInformation;
@@ -34,7 +36,8 @@ import org.springframework.util.Assert;
  */
 public class ConfigurableTypeInformationMapper implements TypeInformationMapper {
 
-	private final Map<ClassTypeInformation<?>, Object> typeMap;
+	private final Map<ClassTypeInformation<?>, Alias> typeToAlias;
+	private final Map<Alias, ClassTypeInformation<?>> aliasToType;
 
 	/**
 	 * Creates a new {@link ConfigurableTypeInformationMapper} for the given type map.
@@ -44,18 +47,22 @@ public class ConfigurableTypeInformationMapper implements TypeInformationMapper
 	public ConfigurableTypeInformationMapper(Map<? extends Class<?>, String> sourceTypeMap) {
 
 		Assert.notNull(sourceTypeMap, "SourceTypeMap must not be null!");
-		this.typeMap = new HashMap<ClassTypeInformation<?>, Object>(sourceTypeMap.size());
+
+		this.typeToAlias = new HashMap<>(sourceTypeMap.size());
+		this.aliasToType = new HashMap<>(sourceTypeMap.size());
 
 		for (Entry<? extends Class<?>, String> entry : sourceTypeMap.entrySet()) {
-			ClassTypeInformation<?> key = ClassTypeInformation.from(entry.getKey());
-			String value = entry.getValue();
 
-			if (typeMap.containsValue(value)) {
-				throw new IllegalArgumentException(String.format(
-						"Detected mapping ambiguity! String %s cannot be mapped to more than one type!", value));
+			ClassTypeInformation<?> type = ClassTypeInformation.from(entry.getKey());
+			Alias alias = Alias.of(entry.getValue());
+
+			if (typeToAlias.containsValue(alias)) {
+				throw new IllegalArgumentException(
+						String.format("Detected mapping ambiguity! String %s cannot be mapped to more than one type!", alias));
 			}
 
-			this.typeMap.put(key, value);
+			this.typeToAlias.put(type, alias);
+			this.aliasToType.put(alias, type);
 		}
 	}
 
@@ -63,26 +70,16 @@ public class ConfigurableTypeInformationMapper implements TypeInformationMapper
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.TypeInformationMapper#createAliasFor(org.springframework.data.util.TypeInformation)
 	 */
-	public Object createAliasFor(TypeInformation<?> type) {
-		return typeMap.get(type);
+	public Alias createAliasFor(TypeInformation<?> type) {
+		return typeToAlias.getOrDefault(type, Alias.NONE);
 	}
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.convert.TypeInformationMapper#resolveTypeFrom(java.lang.Object)
+	 * @see org.springframework.data.convert.TypeInformationMapper#resolveTypeFrom(org.springframework.data.mapping.Alias)
 	 */
-	public ClassTypeInformation<?> resolveTypeFrom(Object alias) {
-
-		if (alias == null) {
-			return null;
-		}
-
-		for (Entry<ClassTypeInformation<?>, Object> entry : typeMap.entrySet()) {
-			if (entry.getValue().equals(alias)) {
-				return entry.getKey();
-			}
-		}
-
-		return null;
+	@Override
+	public Optional<TypeInformation<?>> resolveTypeFrom(Alias alias) {
+		return Optional.ofNullable(aliasToType.get(alias));
 	}
 }

src/main/java/org/springframework/data/convert/DefaultTypeMapper.java

@@ -20,11 +20,14 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Optionals;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 
@@ -41,7 +44,7 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 
 	private final TypeAliasAccessor<S> accessor;
 	private final List<? extends TypeInformationMapper> mappers;
-	private final Map<Object, TypeInformation<?>> typeCache;
+	private final Map<Alias, Optional<TypeInformation<?>>> typeCache;
 
 	/**
 	 * Creates a new {@link DefaultTypeMapper} using the given {@link TypeAliasAccessor}. It will use a
@@ -80,7 +83,7 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 		Assert.notNull(accessor, "Accessor must not be null!");
 		Assert.notNull(additionalMappers, "AdditionalMappers must not be null!");
 
-		List<TypeInformationMapper> mappers = new ArrayList<TypeInformationMapper>(additionalMappers.size() + 1);
+		List<TypeInformationMapper> mappers = new ArrayList<>(additionalMappers.size() + 1);
 		if (mappingContext != null) {
 			mappers.add(new MappingContextTypeInformationMapper(mappingContext));
 		}
@@ -88,19 +91,18 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 
 		this.mappers = Collections.unmodifiableList(mappers);
 		this.accessor = accessor;
-		this.typeCache = new ConcurrentHashMap<Object, TypeInformation<?>>();
+		this.typeCache = new ConcurrentHashMap<>();
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.TypeMapper#readType(java.lang.Object)
 	 */
-	public TypeInformation<?> readType(S source) {
+	public Optional<TypeInformation<?>> readType(S source) {
 
 		Assert.notNull(source, "Source object must not be null!");
 
-		Object alias = accessor.readAliasFrom(source);
-		return alias == null ? null : getFromCacheOrCreate(alias);
+		return getFromCacheOrCreate(accessor.readAliasFrom(source));
 	}
 
 	/**
@@ -110,53 +112,41 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 	 * @param alias
 	 * @return
 	 */
-	private TypeInformation<?> getFromCacheOrCreate(Object alias) {
-
-		TypeInformation<?> typeInformation = typeCache.get(alias);
-
-		if (typeInformation != null) {
-			return typeInformation;
-		}
-
-		for (TypeInformationMapper mapper : mappers) {
-
-			typeInformation = mapper.resolveTypeFrom(alias);
-
-			if (typeInformation != null) {
-				typeCache.put(alias, typeInformation);
-				return typeInformation;
-			}
-		}
-
-		return typeInformation;
+	private Optional<TypeInformation<?>> getFromCacheOrCreate(Alias alias) {
+		return typeCache.computeIfAbsent(alias, key -> Optionals.firstNonEmpty(mappers, it -> it.resolveTypeFrom(alias)));
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.TypeMapper#readType(java.lang.Object, org.springframework.data.util.TypeInformation)
 	 */
-	@SuppressWarnings("unchecked")
 	public <T> TypeInformation<? extends T> readType(S source, TypeInformation<T> basicType) {
 
-		Assert.notNull(source, "Source object must not be null!");
-		Class<?> documentsTargetType = getDefaultedTypeToBeUsed(source);
+		Assert.notNull(source, "Source must not be null!");
+		Assert.notNull(basicType, "Basic type must not be null!");
+
+		Optional<TypeInformation<? extends T>> calculated = getDefaultedTypeToBeUsed(source)//
+				.map(it -> foo(it, basicType));
 
-		if (documentsTargetType == null) {
-			return basicType;
+		return calculated.orElse(basicType);
 	}
 
-		Class<T> rawType = basicType == null ? null : basicType.getType();
+	// @SuppressWarnings("unchecked")
+	private static <T> TypeInformation<? extends T> foo(Class<?> sourceType, TypeInformation<T> type) {
 
-		boolean isMoreConcreteCustomType = rawType == null ? true
-				: rawType.isAssignableFrom(documentsTargetType) && !rawType.equals(documentsTargetType);
+		return specializeOrDefault(sourceType, type);
 
-		if (!isMoreConcreteCustomType) {
-			return basicType;
+		// return type//
+		// .<TypeInformation<? extends T>>map(it -> specializeOrDefault(sourceType, it))
+		// .orElseGet(() -> (TypeInformation<? extends T>) ClassTypeInformation.from(sourceType));
 	}
 
-		ClassTypeInformation<?> targetType = ClassTypeInformation.from(documentsTargetType);
+	private static <T> TypeInformation<? extends T> specializeOrDefault(Class<?> it, TypeInformation<T> type) {
 
-		return (TypeInformation<? extends T>) (basicType != null ? basicType.specialize(targetType) : targetType);
+		ClassTypeInformation<?> targetType = ClassTypeInformation.from(it);
+		Class<T> rawType = type.getType();
+
+		return rawType.isAssignableFrom(it) && !rawType.equals(it) ? type.specialize(targetType) : type;
 	}
 
 	/**
@@ -166,12 +156,9 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 	 * @param source
 	 * @return
 	 */
-	private Class<?> getDefaultedTypeToBeUsed(S source) {
-
-		TypeInformation<?> documentsTargetTypeInformation = readType(source);
-		documentsTargetTypeInformation = documentsTargetTypeInformation == null ? getFallbackTypeFor(source)
-				: documentsTargetTypeInformation;
-		return documentsTargetTypeInformation == null ? null : documentsTargetTypeInformation.getType();
+	private Optional<Class<?>> getDefaultedTypeToBeUsed(S source) {
+		return readType(source).map(it -> readType(source)).orElseGet(() -> getFallbackTypeFor(source))
+				.map(it -> it.getType());
 	}
 
 	/**
@@ -180,8 +167,8 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 	 * @param source will never be {@literal null}.
 	 * @return
 	 */
-	protected TypeInformation<?> getFallbackTypeFor(S source) {
-		return null;
+	protected Optional<TypeInformation<?>> getFallbackTypeFor(S source) {
+		return Optional.empty();
 	}
 
 	/*
@@ -200,10 +187,7 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 
 		Assert.notNull(info, "TypeInformation must not be null!");
 
-		Object alias = getAliasFor(info);
-		if (alias != null) {
-			accessor.writeTypeTo(sink, alias);
-		}
+		getAliasFor(info).getValue().ifPresent(it -> accessor.writeTypeTo(sink, it));
 	}
 
 	/**
@@ -213,17 +197,10 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 	 * @return the alias for the given {@link TypeInformation} or {@literal null} of none was found or all mappers
 	 *         returned {@literal null}.
 	 */
-	protected final Object getAliasFor(TypeInformation<?> info) {
+	protected final Alias getAliasFor(TypeInformation<?> info) {
 
 		Assert.notNull(info, "TypeInformation must not be null!");
 
-		for (TypeInformationMapper mapper : mappers) {
-			Object alias = mapper.createAliasFor(info);
-			if (alias != null) {
-				return alias;
-			}
-		}
-
-		return null;
+		return Optionals.firstNonEmpty(mappers, it -> it.createAliasFor(info), Alias.NONE);
 	}
 }

src/main/java/org/springframework/data/convert/MappingContextTypeInformationMapper.java

@@ -17,11 +17,12 @@ package org.springframework.data.convert;
 
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.MappingContext;
-import org.springframework.data.util.CacheValue;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
@@ -35,7 +36,7 @@ import org.springframework.util.Assert;
  */
 public class MappingContextTypeInformationMapper implements TypeInformationMapper {
 
-	private final Map<ClassTypeInformation<?>, CacheValue<Object>> typeMap;
+	private final Map<ClassTypeInformation<?>, Alias> typeMap;
 	private final MappingContext<? extends PersistentEntity<?, ?>, ?> mappingContext;
 
 	/**
@@ -48,11 +49,11 @@ public class MappingContextTypeInformationMapper implements TypeInformationMappe
 
 		Assert.notNull(mappingContext, "MappingContext must not be null!");
 
-		this.typeMap = new ConcurrentHashMap<ClassTypeInformation<?>, CacheValue<Object>>();
+		this.typeMap = new ConcurrentHashMap<>();
 		this.mappingContext = mappingContext;
 
 		for (PersistentEntity<?, ?> entity : mappingContext.getPersistentEntities()) {
-			safelyAddToCache(entity.getTypeInformation().getRawTypeInformation(), entity.getTypeAlias());
+			verify(entity.getTypeInformation().getRawTypeInformation(), entity.getTypeAlias());
 		}
 	}
 
@@ -60,24 +61,11 @@ public class MappingContextTypeInformationMapper implements TypeInformationMappe
 	 * (non-Javadoc)
 	 * @see org.springframework.data.convert.TypeInformationMapper#createAliasFor(org.springframework.data.util.TypeInformation)
 	 */
-	public Object createAliasFor(TypeInformation<?> type) {
+	public Alias createAliasFor(TypeInformation<?> type) {
 
-		CacheValue<Object> key = typeMap.get(type);
-
-		if (key != null) {
-			return key.getValue();
-		}
-
-		PersistentEntity<?, ?> entity = mappingContext.getPersistentEntity(type);
-
-		if (entity == null) {
-			return null;
-		}
-
-		Object alias = entity.getTypeAlias();
-		safelyAddToCache(type.getRawTypeInformation(), alias);
-
-		return alias;
+		return typeMap.computeIfAbsent(type.getRawTypeInformation(), key -> {
+			return verify(key, mappingContext.getPersistentEntity(key).map(it -> it.getTypeAlias()).orElse(Alias.NONE));
+		});
 	}
 
 	/**
@@ -86,73 +74,59 @@ public class MappingContextTypeInformationMapper implements TypeInformationMappe
 	 * @param key must not be {@literal null}.
 	 * @param alias can be {@literal null}.
 	 */
-	private void safelyAddToCache(ClassTypeInformation<?> key, Object alias) {
-
-		CacheValue<Object> aliasToBeCached = CacheValue.ofNullable(alias);
+	private Alias verify(ClassTypeInformation<?> key, Alias alias) {
 
-		if (alias == null && !typeMap.containsKey(key)) {
-			typeMap.put(key, aliasToBeCached);
-			return;
-		}
+		// Reject second alias for same type
 
-		CacheValue<Object> alreadyCachedAlias = typeMap.get(key);
+		Alias existingAlias = typeMap.getOrDefault(key, Alias.NONE);
 
-		// Reject second alias for same type
+		if (existingAlias.isPresentButDifferent(alias)) {
 
-		if (alreadyCachedAlias != null && alreadyCachedAlias.isPresent() && !alreadyCachedAlias.hasValue(alias)) {
-			throw new IllegalArgumentException(String.format(
-					"Trying to register alias '%s', but found already registered alias '%s' for type %s!", alias,
-					alreadyCachedAlias, key));
+			throw new IllegalArgumentException(
+					String.format("Trying to register alias '%s', but found already registered alias '%s' for type %s!", alias,
+							existingAlias, key));
 		}
 
 		// Reject second type for same alias
 
-		if (typeMap.containsValue(aliasToBeCached)) {
-
-			for (Entry<ClassTypeInformation<?>, CacheValue<Object>> entry : typeMap.entrySet()) {
-
-				CacheValue<Object> value = entry.getValue();
+		if (typeMap.containsValue(alias)) {
 
-				if (!value.isPresent()) {
-					continue;
-				}
+			typeMap.entrySet().stream()//
+					.filter(it -> it.getValue().hasSamePresentValueAs(alias) && !it.getKey().equals(key))//
+					.findFirst().ifPresent(it -> {
 
-				if (value.hasValue(alias) && !entry.getKey().equals(key)) {
 						throw new IllegalArgumentException(String.format(
 								"Detected existing type mapping of %s to alias '%s' but attempted to bind the same alias to %s!", key,
-							alias, entry.getKey()));
-				}
-			}
+								alias, it.getKey()));
+					});
 		}
 
-		typeMap.put(key, aliasToBeCached);
+		return alias;
 	}
 
 	/* 
 	 * (non-Javadoc)
-	 * @see org.springframework.data.convert.TypeInformationMapper#resolveTypeFrom(java.lang.Object)
+	 * @see org.springframework.data.convert.TypeInformationMapper#resolveTypeFrom(java.util.Optional)
 	 */
-	public ClassTypeInformation<?> resolveTypeFrom(Object alias) {
-
-		if (alias == null) {
-			return null;
-		}
-
-		for (Entry<ClassTypeInformation<?>, CacheValue<Object>> entry : typeMap.entrySet()) {
+	@Override
+	public Optional<TypeInformation<?>> resolveTypeFrom(Alias alias) {
 
-			CacheValue<Object> cachedAlias = entry.getValue();
+		return alias.getValue().map(it -> {
 
-			if (cachedAlias.hasValue(alias)) {
+			for (Entry<ClassTypeInformation<?>, Alias> entry : typeMap.entrySet()) {
+				if (entry.getValue().hasValue(it)) {
 					return entry.getKey();
 				}
 			}
 
 			for (PersistentEntity<?, ?> entity : mappingContext.getPersistentEntities()) {
-			if (alias.equals(entity.getTypeAlias())) {
+
+				if (entity.getTypeAlias().hasValue(it)) {
 					return entity.getTypeInformation().getRawTypeInformation();
 				}
 			}
 
 			return null;
+		});
 	}
 }

src/main/java/org/springframework/data/convert/ReflectionEntityInstantiator.java

@@ -49,7 +49,7 @@ public enum ReflectionEntityInstantiator implements EntityInstantiator {
 					.map(it -> constructor.getParameters().stream()//
 							.map(parameter -> it.getParameterValue(parameter).orElse(null))//
 							.collect(Collectors.toList()))//
-					.orElse(Collections.emptyList());
+					.orElseGet(() -> Collections.emptyList());
 
 			try {
 				return (T) BeanUtils.instantiateClass(constructor.getConstructor(), params.toArray());

src/main/java/org/springframework/data/convert/SimpleTypeInformationMapper.java

@@ -16,12 +16,13 @@
 package org.springframework.data.convert;
 
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.StringUtils;
 
 /**
  * Basic {@link TypeInformationMapper} implementation that interprets the alias handles as fully qualified class name
@@ -32,7 +33,7 @@ import org.springframework.util.StringUtils;
  */
 public class SimpleTypeInformationMapper implements TypeInformationMapper {
 
-	private final Map<String, ClassTypeInformation<?>> CACHE = new ConcurrentHashMap<String, ClassTypeInformation<?>>();
+	private final Map<String, Optional<ClassTypeInformation<?>>> CACHE = new ConcurrentHashMap<>();
 
 	/**
 	 * Returns the {@link TypeInformation} that shall be used when the given {@link String} value is found as type hint.
@@ -43,35 +44,11 @@ public class SimpleTypeInformationMapper implements TypeInformationMapper {
 	 * @return the type to be used for the given {@link String} representation or {@literal null} if nothing found or the
 	 *         class cannot be loaded.
 	 */
-	public ClassTypeInformation<?> resolveTypeFrom(Object alias) {
+	@Override
+	public Optional<TypeInformation<?>> resolveTypeFrom(Alias alias) {
 
-		if (!(alias instanceof String)) {
-			return null;
-		}
-
-		String value = (String) alias;
-
-		if (!StringUtils.hasText(value)) {
-			return null;
-		}
-
-		ClassTypeInformation<?> information = CACHE.get(value);
-
-		if (information != null) {
-			return information;
-		}
-
-		try {
-			information = ClassTypeInformation.from(ClassUtils.forName(value, null));
-		} catch (ClassNotFoundException e) {
-			return null;
-		}
-
-		if (information != null) {
-			CACHE.put(value, information);
-		}
-
-		return information;
+		return alias.mapTyped(String.class)//
+				.flatMap(it -> CACHE.computeIfAbsent(it, SimpleTypeInformationMapper::loadClass).map(type -> type));
 	}
 
 	/**
@@ -81,7 +58,16 @@ public class SimpleTypeInformationMapper implements TypeInformationMapper {
 	 * @param typeInformation must not be {@literal null}.
 	 * @return the String representation to be stored or {@literal null} if no type information shall be stored.
 	 */
-	public String createAliasFor(TypeInformation<?> type) {
-		return type.getType().getName();
+	public Alias createAliasFor(TypeInformation<?> type) {
+		return Alias.of(type.getType().getName());
+	}
+
+	private static Optional<ClassTypeInformation<?>> loadClass(String typeName) {
+
+		try {
+			return Optional.of(ClassTypeInformation.from(ClassUtils.forName(typeName, null)));
+		} catch (ClassNotFoundException e) {
+			return Optional.empty();
+		}
 	}
 }

src/main/java/org/springframework/data/convert/TypeAliasAccessor.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.convert;
 
+import org.springframework.data.mapping.Alias;
+
 /**
  * Interface to abstract implementations of how to access a type alias from a given source or sink.
  * 
@@ -28,7 +30,7 @@ public interface TypeAliasAccessor<S> {
 	 * @param source
 	 * @return can be {@literal null} in case no alias was found.
 	 */
-	Object readAliasFrom(S source);
+	Alias readAliasFrom(S source);
 
 	/**
 	 * Writes the given type alias to the given sink.

src/main/java/org/springframework/data/convert/TypeInformationMapper.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.data.convert;
 
+import java.util.Optional;
+
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.util.TypeInformation;
 
 /**
@@ -30,7 +33,7 @@ public interface TypeInformationMapper {
 	 * @param alias can be {@literal null}.
 	 * @return
 	 */
-	TypeInformation<?> resolveTypeFrom(Object alias);
+	Optional<TypeInformation<?>> resolveTypeFrom(Alias alias);
 
 	/**
 	 * Returns the alias to be used for the given {@link TypeInformation}.
@@ -38,5 +41,5 @@ public interface TypeInformationMapper {
 	 * @param type
 	 * @return
 	 */
-	Object createAliasFor(TypeInformation<?> type);
+	Alias createAliasFor(TypeInformation<?> type);
 }

src/main/java/org/springframework/data/convert/TypeMapper.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.convert;
 
+import java.util.Optional;
+
 import org.springframework.data.util.TypeInformation;
 
 /**
@@ -30,7 +32,7 @@ public interface TypeMapper<S> {
 	 * @param source must not be {@literal null}.
 	 * @return
 	 */
-	TypeInformation<?> readType(S source);
+	Optional<TypeInformation<?>> readType(S source);
 
 	/**
 	 * Returns the {@link TypeInformation} from the given source if it is a more concrete type than the given default one.

src/main/java/org/springframework/data/domain/AbstractPageRequest.java

@@ -71,7 +71,7 @@ public abstract class AbstractPageRequest implements Pageable, Serializable {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.domain.Pageable#getOffset()
 	 */
-	public int getOffset() {
+	public long getOffset() {
 		return page * size;
 	}
 

src/main/java/org/springframework/data/domain/Chunk.java

@@ -20,6 +20,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.util.Assert;
@@ -34,14 +35,14 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 
 	private static final long serialVersionUID = 867755909294344406L;
 
-	private final List<T> content = new ArrayList<T>();
+	private final List<T> content = new ArrayList<>();
 	private final Pageable pageable;
 
 	/**
 	 * Creates a new {@link Chunk} with the given content and the given governing {@link Pageable}.
 	 * 
 	 * @param content must not be {@literal null}.
-	 * @param pageable can be {@literal null}.
+	 * @param pageable must not be {@literal null}.
 	 */
 	public Chunk(List<T> content, Pageable pageable) {
 
@@ -56,7 +57,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * @see org.springframework.data.domain.Slice#getNumber()
 	 */
 	public int getNumber() {
-		return pageable == null ? 0 : pageable.getPageNumber();
+		return pageable == Pageable.NONE ? 0 : pageable.getPageNumber();
 	}
 
 	/*
@@ -64,7 +65,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * @see org.springframework.data.domain.Slice#getSize()
 	 */
 	public int getSize() {
-		return pageable == null ? 0 : pageable.getPageSize();
+		return pageable == Pageable.NONE ? 0 : pageable.getPageSize();
 	}
 
 	/*
@@ -104,7 +105,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * @see org.springframework.data.domain.Slice#nextPageable()
 	 */
 	public Pageable nextPageable() {
-		return hasNext() ? pageable.next() : null;
+		return hasNext() ? pageable.next() : Pageable.NONE;
 	}
 
 	/*
@@ -112,12 +113,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * @see org.springframework.data.domain.Slice#previousPageable()
 	 */
 	public Pageable previousPageable() {
-
-		if (hasPrevious()) {
-			return pageable.previousOrFirst();
-		}
-
-		return null;
+		return hasPrevious() ? pageable.previousOrFirst() : Pageable.NONE;
 	}
 
 	/*
@@ -140,8 +136,9 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.domain.Slice#getSort()
 	 */
+	@Override
 	public Sort getSort() {
-		return pageable == null ? null : pageable.getSort();
+		return pageable.getSort();
 	}
 
 	/*
@@ -158,17 +155,11 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 	 * @param converter must not be {@literal null}.
 	 * @return
 	 */
-	protected <S> List<S> getConvertedContent(Converter<? super T, ? extends S> converter) {
+	protected <U> List<U> getConvertedContent(Converter<? super T, ? extends U> converter) {
 
 		Assert.notNull(converter, "Converter must not be null!");
 
-		List<S> result = new ArrayList<S>(content.size());
-
-		for (T element : this) {
-			result.add(converter.convert(element));
-		}
-
-		return result;
+		return this.stream().map(it -> converter.convert(it)).collect(Collectors.toList());
 	}
 
 	/*
@@ -189,7 +180,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 		Chunk<?> that = (Chunk<?>) obj;
 
 		boolean contentEqual = this.content.equals(that.content);
-		boolean pageableEqual = this.pageable == null ? that.pageable == null : this.pageable.equals(that.pageable);
+		boolean pageableEqual = this.pageable.equals(that.pageable);
 
 		return contentEqual && pageableEqual;
 	}
@@ -203,7 +194,7 @@ abstract class Chunk<T> implements Slice<T>, Serializable {
 
 		int result = 17;
 
-		result += 31 * (pageable == null ? 0 : pageable.hashCode());
+		result += 31 * pageable.hashCode();
 		result += 31 * content.hashCode();
 
 		return result;

src/main/java/org/springframework/data/domain/Example.java

@@ -48,7 +48,7 @@ public class Example<T> {
 	 * @return
 	 */
 	public static <T> Example<T> of(T probe) {
-		return new Example<T>(probe, ExampleMatcher.matching());
+		return new Example<>(probe, ExampleMatcher.matching());
 	}
 
 	/**
@@ -59,7 +59,7 @@ public class Example<T> {
 	 * @return
 	 */
 	public static <T> Example<T> of(T probe, ExampleMatcher matcher) {
-		return new Example<T>(probe, matcher);
+		return new Example<>(probe, matcher);
 	}
 
 	/**

src/main/java/org/springframework/data/domain/ExampleMatcher.java

@@ -112,7 +112,7 @@ public class ExampleMatcher {
 		Assert.notEmpty(ignoredPaths, "IgnoredPaths must not be empty!");
 		Assert.noNullElements(ignoredPaths, "IgnoredPaths must not contain null elements!");
 
-		Set<String> newIgnoredPaths = new LinkedHashSet<String>(this.ignoredPaths);
+		Set<String> newIgnoredPaths = new LinkedHashSet<>(this.ignoredPaths);
 		newIgnoredPaths.addAll(Arrays.asList(ignoredPaths));
 
 		return new ExampleMatcher(nullHandler, defaultStringMatcher, propertySpecifiers, newIgnoredPaths, defaultIgnoreCase,

src/main/java/org/springframework/data/domain/Page.java

@@ -47,5 +47,5 @@ public interface Page<T> extends Slice<T> {
 	 * @return a new {@link Page} with the content of the current one mapped by the given {@link Converter}.
 	 * @since 1.10
 	 */
-	<S> Page<S> map(Converter<? super T, ? extends S> converter);
+	<U> Page<U> map(Converter<? super T, ? extends U> converter);
 }

src/main/java/org/springframework/data/domain/PageImpl.java

@@ -16,6 +16,7 @@
 package org.springframework.data.domain;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.core.convert.converter.Converter;
 
@@ -45,8 +46,13 @@ public class PageImpl<T> extends Chunk<T> implements Page<T> {
 		super(content, pageable);
 
 		this.pageable = pageable;
-		this.total = !content.isEmpty() && pageable != null && pageable.getOffset() + pageable.getPageSize() > total
-				? pageable.getOffset() + content.size() : total;
+
+		Optional<Pageable> foo = Pageable.NONE == pageable ? Optional.empty() : Optional.of(pageable);
+
+		this.total = foo.filter(it -> !content.isEmpty())//
+				.filter(it -> it.getOffset() + it.getPageSize() > total)//
+				.map(it -> it.getOffset() + content.size())//
+				.orElse(total);
 	}
 
 	/**
@@ -56,7 +62,7 @@ public class PageImpl<T> extends Chunk<T> implements Page<T> {
 	 * @param content must not be {@literal null}.
 	 */
 	public PageImpl(List<T> content) {
-		this(content, null, null == content ? 0 : content.size());
+		this(content, Pageable.NONE, null == content ? 0 : content.size());
 	}
 
 	/*
@@ -100,8 +106,8 @@ public class PageImpl<T> extends Chunk<T> implements Page<T> {
 	 * @see org.springframework.data.domain.Slice#transform(org.springframework.core.convert.converter.Converter)
 	 */
 	@Override
-	public <S> Page<S> map(Converter<? super T, ? extends S> converter) {
-		return new PageImpl<S>(getConvertedContent(converter), pageable, total);
+	public <U> Page<U> map(Converter<? super T, ? extends U> converter) {
+		return new PageImpl<>(getConvertedContent(converter), pageable, total);
 	}
 
 	/*

src/main/java/org/springframework/data/domain/PageRequest.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.domain;
 
+import java.util.Optional;
+
 import org.springframework.data.domain.Sort.Direction;
 
 /**
@@ -35,9 +37,11 @@ public class PageRequest extends AbstractPageRequest {
 	 * 
 	 * @param page zero-based page index.
 	 * @param size the size of the page to be returned.
+	 * @deprecated use {@link #of(int, int)} instead.
 	 */
+	@Deprecated
 	public PageRequest(int page, int size) {
-		this(page, size, null);
+		this(page, size, Sort.unsorted());
 	}
 
 	/**
@@ -47,7 +51,9 @@ public class PageRequest extends AbstractPageRequest {
 	 * @param size the size of the page to be returned.
 	 * @param direction the direction of the {@link Sort} to be specified, can be {@literal null}.
 	 * @param properties the properties to sort by, must not be {@literal null} or empty.
+	 * @deprecated use {@link #of(int, int, Direction, String...)} instead.
 	 */
+	@Deprecated
 	public PageRequest(int page, int size, Direction direction, String... properties) {
 		this(page, size, new Sort(direction, properties));
 	}
@@ -58,12 +64,28 @@ public class PageRequest extends AbstractPageRequest {
 	 * @param page zero-based page index.
 	 * @param size the size of the page to be returned.
 	 * @param sort can be {@literal null}.
+	 * @deprecated use {@link #of(int, int, Optional)} instead.
 	 */
+	@Deprecated
 	public PageRequest(int page, int size, Sort sort) {
+
 		super(page, size);
+
 		this.sort = sort;
 	}
 
+	public static PageRequest of(int page, int site) {
+		return of(page, site, Sort.unsorted());
+	}
+
+	public static PageRequest of(int page, int site, Sort sort) {
+		return new PageRequest(page, site, sort);
+	}
+
+	public static PageRequest of(int page, int size, Direction direction, String... properties) {
+		return of(page, size, new Sort(direction, properties));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.domain.Pageable#getSort()
@@ -113,9 +135,7 @@ public class PageRequest extends AbstractPageRequest {
 
 		PageRequest that = (PageRequest) obj;
 
-		boolean sortEqual = this.sort == null ? that.sort == null : this.sort.equals(that.sort);
-
-		return super.equals(that) && sortEqual;
+		return super.equals(that) && this.sort.equals(that.sort);
 	}
 
 	/*
@@ -124,7 +144,7 @@ public class PageRequest extends AbstractPageRequest {
 	 */
 	@Override
 	public int hashCode() {
-		return 31 * super.hashCode() + (null == sort ? 0 : sort.hashCode());
+		return 31 * super.hashCode() + sort.hashCode();
 	}
 
 	/* 
@@ -133,7 +153,6 @@ public class PageRequest extends AbstractPageRequest {
 	 */
 	@Override
 	public String toString() {
-		return String.format("Page request [number: %d, size %d, sort: %s]", getPageNumber(), getPageSize(),
-				sort == null ? null : sort.toString());
+		return String.format("Page request [number: %d, size %d, sort: %s]", getPageNumber(), getPageSize(), sort);
 	}
 }

src/main/java/org/springframework/data/domain/Pageable.java

@@ -41,7 +41,7 @@ public interface Pageable {
 	 * 
 	 * @return the offset to be taken
 	 */
-	int getOffset();
+	long getOffset();
 
 	/**
 	 * Returns the sorting parameters.
@@ -50,6 +50,10 @@ public interface Pageable {
 	 */
 	Sort getSort();
 
+	default Sort getSortOr(Sort sort) {
+		return getSort().isSorted() ? getSort() : sort;
+	}
+
 	/**
 	 * Returns the {@link Pageable} requesting the next {@link Page}.
 	 * 
@@ -78,4 +82,47 @@ public interface Pageable {
 	 * @return
 	 */
 	boolean hasPrevious();
+
+	public static Pageable NONE = new Pageable() {
+
+		@Override
+		public Pageable previousOrFirst() {
+			return this;
+		}
+
+		@Override
+		public Pageable next() {
+			return this;
+		}
+
+		@Override
+		public boolean hasPrevious() {
+			return false;
+		}
+
+		@Override
+		public Sort getSort() {
+			return Sort.unsorted();
+		}
+
+		@Override
+		public int getPageSize() {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public int getPageNumber() {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public long getOffset() {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public Pageable first() {
+			return this;
+		}
+	};
 }

src/main/java/org/springframework/data/domain/Slice.java

@@ -18,6 +18,7 @@ package org.springframework.data.domain;
 import java.util.List;
 
 import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.util.Streamable;
 
 /**
  * A slice of data that indicates whether there's a next or previous slice available. Allows to obtain a
@@ -26,7 +27,7 @@ import org.springframework.core.convert.converter.Converter;
  * @author Oliver Gierke
  * @since 1.8
  */
-public interface Slice<T> extends Iterable<T> {
+public interface Slice<T> extends Streamable<T> {
 
 	/**
 	 * Returns the number of the current {@link Slice}. Is always non-negative.
@@ -123,5 +124,5 @@ public interface Slice<T> extends Iterable<T> {
 	 * @return a new {@link Slice} with the content of the current one mapped by the given {@link Converter}.
 	 * @since 1.10
 	 */
-	<S> Slice<S> map(Converter<? super T, ? extends S> converter);
+	<U> Slice<U> map(Converter<? super T, ? extends U> converter);
 }

src/main/java/org/springframework/data/domain/SliceImpl.java

@@ -42,6 +42,7 @@ public class SliceImpl<T> extends Chunk<T> {
 	public SliceImpl(List<T> content, Pageable pageable, boolean hasNext) {
 
 		super(content, pageable);
+
 		this.hasNext = hasNext;
 		this.pageable = pageable;
 	}
@@ -69,8 +70,8 @@ public class SliceImpl<T> extends Chunk<T> {
 	 * @see org.springframework.data.domain.Slice#transform(org.springframework.core.convert.converter.Converter)
 	 */
 	@Override
-	public <S> Slice<S> map(Converter<? super T, ? extends S> converter) {
-		return new SliceImpl<S>(getConvertedContent(converter), pageable, hasNext);
+	public <U> Slice<U> map(Converter<? super T, ? extends U> converter) {
+		return new SliceImpl<>(getConvertedContent(converter), pageable, hasNext);
 	}
 
 	/*

src/main/java/org/springframework/data/domain/Sort.java

@@ -18,10 +18,14 @@ package org.springframework.data.domain;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -34,6 +38,9 @@ import org.springframework.util.StringUtils;
 public class Sort implements Iterable<org.springframework.data.domain.Sort.Order>, Serializable {
 
 	private static final long serialVersionUID = 5737186511678863905L;
+
+	private static final Sort UNSORTED = new Sort(new Order[0]);
+
 	public static final Direction DEFAULT_DIRECTION = Direction.ASC;
 
 	private final List<Order> orders;
@@ -43,6 +50,7 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 	 * 
 	 * @param orders must not be {@literal null}.
 	 */
+	@Deprecated
 	public Sort(Order... orders) {
 		this(Arrays.asList(orders));
 	}
@@ -51,21 +59,23 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 	 * Creates a new {@link Sort} instance.
 	 * 
 	 * @param orders must not be {@literal null} or contain {@literal null}.
+	 * @deprecated see {@link Sort#by(List)}
 	 */
+	@Deprecated
 	public Sort(List<Order> orders) {
 
-		if (null == orders || orders.isEmpty()) {
-			throw new IllegalArgumentException("You have to provide at least one sort property to sort by!");
-		}
+		Assert.notNull(orders, "Orders must not be null!");
 
-		this.orders = orders;
+		this.orders = Collections.unmodifiableList(orders);
 	}
 
 	/**
 	 * Creates a new {@link Sort} instance. Order defaults to {@value Direction#ASC}.
 	 * 
 	 * @param properties must not be {@literal null} or contain {@literal null} or empty strings
+	 * @deprecated use {@link Sort#by(String...)}
 	 */
+	@Deprecated
 	public Sort(String... properties) {
 		this(DEFAULT_DIRECTION, properties);
 	}
@@ -77,7 +87,7 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 	 * @param properties must not be {@literal null}, empty or contain {@literal null} or empty strings.
 	 */
 	public Sort(Direction direction, String... properties) {
-		this(direction, properties == null ? new ArrayList<String>() : Arrays.asList(properties));
+		this(direction, properties == null ? new ArrayList<>() : Arrays.asList(properties));
 	}
 
 	/**
@@ -92,13 +102,45 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 			throw new IllegalArgumentException("You have to provide at least one property to sort by!");
 		}
 
-		this.orders = new ArrayList<Order>(properties.size());
+		this.orders = new ArrayList<>(properties.size());
 
 		for (String property : properties) {
 			this.orders.add(new Order(direction, property));
 		}
 	}
 
+	public static Sort by(String... properties) {
+		return properties.length == 0 ? Sort.unsorted() : new Sort(properties);
+	}
+
+	public static Sort by(List<Order> orders) {
+		return orders.isEmpty() ? Sort.unsorted() : new Sort(orders);
+	}
+
+	public static Sort by(Order... orders) {
+		return new Sort(orders);
+	}
+
+	public static Sort unsorted() {
+		return UNSORTED;
+	}
+
+	public Sort descending() {
+		return withDirection(Direction.DESC);
+	}
+
+	public Sort ascending() {
+		return withDirection(Direction.ASC);
+	}
+
+	private Sort withDirection(Direction direction) {
+		return new Sort(orders.stream().map(it -> new Order(direction, it.getProperty())).collect(Collectors.toList()));
+	}
+
+	public boolean isSorted() {
+		return !orders.isEmpty();
+	}
+
 	/**
 	 * Returns a new {@link Sort} consisting of the {@link Order}s of the current {@link Sort} combined with the given
 	 * ones.
@@ -112,7 +154,7 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 			return this;
 		}
 
-		ArrayList<Order> these = new ArrayList<Order>(this.orders);
+		ArrayList<Order> these = new ArrayList<>(this.orders);
 
 		for (Order order : sort) {
 			these.add(order);
@@ -184,7 +226,7 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 	 */
 	@Override
 	public String toString() {
-		return StringUtils.collectionToCommaDelimitedString(orders);
+		return orders.isEmpty() ? "UNSORTED" : StringUtils.collectionToCommaDelimitedString(orders);
 	}
 
 	/**
@@ -240,12 +282,12 @@ public class Sort implements Iterable<org.springframework.data.domain.Sort.Order
 		 * @param value
 		 * @return
 		 */
-		public static Direction fromStringOrNull(String value) {
+		public static Optional<Direction> fromOptionalString(String value) {
 
 			try {
-				return fromString(value);
+				return Optional.of(fromString(value));
 			} catch (IllegalArgumentException e) {
-				return null;
+				return Optional.empty();
 			}
 		}
 	}

src/main/java/org/springframework/data/domain/jaxb/PageableAdapter.java

@@ -21,7 +21,6 @@ import javax.xml.bind.annotation.adapters.XmlAdapter;
 
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
-import org.springframework.data.domain.Sort;
 import org.springframework.data.domain.jaxb.SpringDataJaxb.OrderDto;
 import org.springframework.data.domain.jaxb.SpringDataJaxb.PageRequestDto;
 import org.springframework.data.domain.jaxb.SpringDataJaxb.SortDto;
@@ -43,7 +42,7 @@ class PageableAdapter extends XmlAdapter<PageRequestDto, Pageable> {
 		SortDto sortDto = SortAdapter.INSTANCE.marshal(request.getSort());
 
 		PageRequestDto dto = new PageRequestDto();
-		dto.orders = sortDto == null ? Collections.<OrderDto> emptyList() : sortDto.orders;
+		dto.orders = sortDto == null ? Collections.<OrderDto>emptyList() : sortDto.orders;
 		dto.page = request.getPageNumber();
 		dto.size = request.getPageSize();
 
@@ -58,13 +57,12 @@ class PageableAdapter extends XmlAdapter<PageRequestDto, Pageable> {
 	public Pageable unmarshal(PageRequestDto v) {
 
 		if (v.orders.isEmpty()) {
-			return new PageRequest(v.page, v.size);
+			return PageRequest.of(v.page, v.size);
 		}
 
 		SortDto sortDto = new SortDto();
 		sortDto.orders = v.orders;
-		Sort sort = SortAdapter.INSTANCE.unmarshal(sortDto);
 
-		return new PageRequest(v.page, v.size, sort);
+		return PageRequest.of(v.page, v.size, SortAdapter.INSTANCE.unmarshal(sortDto));
 	}
 }

src/main/java/org/springframework/data/domain/jaxb/SortAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -52,6 +52,6 @@ public class SortAdapter extends XmlAdapter<SortDto, Sort> {
 	 */
 	@Override
 	public Sort unmarshal(SortDto source) {
-		return source == null ? null : new Sort(SpringDataJaxb.unmarshal(source.orders, OrderAdapter.INSTANCE));
+		return source == null ? Sort.unsorted() : Sort.by(SpringDataJaxb.unmarshal(source.orders, OrderAdapter.INSTANCE));
 	}
 }

src/main/java/org/springframework/data/domain/jaxb/SpringDataJaxb.java

@@ -60,7 +60,7 @@ public abstract class SpringDataJaxb {
 	public static class PageRequestDto {
 
 		@XmlAttribute int page, size;
-		@XmlElement(name = "order", namespace = NAMESPACE) List<OrderDto> orders = new ArrayList<OrderDto>();
+		@XmlElement(name = "order", namespace = NAMESPACE) List<OrderDto> orders = new ArrayList<>();
 	}
 
 	/**
@@ -72,7 +72,7 @@ public abstract class SpringDataJaxb {
 	@XmlAccessorType(XmlAccessType.FIELD)
 	public static class SortDto {
 
-		@XmlElement(name = "order", namespace = SpringDataJaxb.NAMESPACE) List<OrderDto> orders = new ArrayList<OrderDto>();
+		@XmlElement(name = "order", namespace = SpringDataJaxb.NAMESPACE) List<OrderDto> orders = new ArrayList<>();
 	}
 
 	/**
@@ -116,7 +116,7 @@ public abstract class SpringDataJaxb {
 			return Collections.emptyList();
 		}
 
-		List<T> result = new ArrayList<T>(source.size());
+		List<T> result = new ArrayList<>(source.size());
 
 		for (S element : source) {
 			try {
@@ -144,7 +144,7 @@ public abstract class SpringDataJaxb {
 			return Collections.emptyList();
 		}
 
-		List<S> result = new ArrayList<S>();
+		List<S> result = new ArrayList<>();
 
 		for (T element : source) {
 			try {

src/main/java/org/springframework/data/geo/Distance.java

@@ -63,7 +63,7 @@ public class Distance implements Serializable, Comparable<Distance> {
 	 * @return will never be {@literal null}.
 	 */
 	public static Range<Distance> between(Distance min, Distance max) {
-		return new Range<Distance>(min, max);
+		return new Range<>(min, max);
 	}
 
 	/**

src/main/java/org/springframework/data/geo/Polygon.java

@@ -53,7 +53,7 @@ public class Polygon implements Iterable<Point>, Shape {
 		Assert.notNull(z, "Z coordinate must not be null!");
 		Assert.notNull(others, "Others must not be null!");
 
-		List<Point> points = new ArrayList<Point>(3 + others.length);
+		List<Point> points = new ArrayList<>(3 + others.length);
 		points.addAll(Arrays.asList(x, y, z));
 		points.addAll(Arrays.asList(others));
 
@@ -70,7 +70,7 @@ public class Polygon implements Iterable<Point>, Shape {
 
 		Assert.notNull(points, "Points must not be null!");
 
-		List<Point> pointsToSet = new ArrayList<Point>(points.size());
+		List<Point> pointsToSet = new ArrayList<>(points.size());
 
 		for (Point point : points) {
 

src/main/java/org/springframework/data/mapping/Alias.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mapping;
+
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+
+import java.util.Optional;
+
+/**
+ * @author Oliver Gierke
+ */
+@Value
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public class Alias {
+
+	public static Alias NONE = new Alias(Optional.empty());
+
+	Optional<? extends Object> value;
+
+	public static Alias of(Object alias) {
+		return ofOptional(Optional.of(alias));
+	}
+
+	public static Alias ofOptional(Optional<? extends Object> optional) {
+		return optional.isPresent() ? new Alias(optional) : NONE;
+	}
+
+	public boolean isPresentButDifferent(Alias other) {
+		return isPresent() && !hasValue(other.value);
+	}
+
+	public boolean hasValue(Object that) {
+		return value.filter(it -> it.equals(that)).isPresent();
+	}
+
+	public boolean hasSamePresentValueAs(Alias other) {
+		return isPresent() && hasValue(other.value);
+	}
+
+	public boolean isPresent() {
+		return value.isPresent();
+	}
+
+	public <T> Optional<T> mapTyped(Class<T> type) {
+		return value.filter(it -> type.isInstance(it)).map(it -> type.cast(it));
+	}
+
+	public String toString() {
+		return value.map(Object::toString).orElse("NONE");
+	}
+}

src/main/java/org/springframework/data/mapping/IdentifierAccessor.java

@@ -29,5 +29,5 @@ public interface IdentifierAccessor {
 	 * 
 	 * @return
 	 */
-	Optional<? extends Object> getIdentifier();
+	Optional<Object> getIdentifier();
 }

src/main/java/org/springframework/data/mapping/PersistentEntity.java

@@ -135,7 +135,7 @@ public interface PersistentEntity<T, P extends PersistentProperty<P>> {
 	 * 
 	 * @return
 	 */
-	Optional<? extends Object> getTypeAlias();
+	Alias getTypeAlias();
 
 	/**
 	 * Returns the {@link TypeInformation} backing this {@link PersistentEntity}.

src/main/java/org/springframework/data/mapping/PersistentProperty.java

@@ -89,7 +89,7 @@ public interface PersistentProperty<P extends PersistentProperty<P>> {
 
 	Optional<String> getSpelExpression();
 
-	Association<P> getAssociation();
+	Optional<Association<P>> getAssociation();
 
 	/**
 	 * Returns whether the type of the {@link PersistentProperty} is actually to be regarded as {@link PersistentEntity}
@@ -199,7 +199,7 @@ public interface PersistentProperty<P extends PersistentProperty<P>> {
 	 * potentially backing field and traverse accessor methods to potentially available super types.
 	 * 
 	 * @param annotationType the annotation to look up, must not be {@literal null}.
-	 * @return the annotation of the given type if present or {@literal null} otherwise.
+	 * @return the annotation of the given type.
 	 * @see AnnotationUtils#findAnnotation(Method, Class)
 	 */
 	<A extends Annotation> Optional<A> findAnnotation(Class<A> annotationType);

src/main/java/org/springframework/data/mapping/PersistentPropertyAccessor.java

@@ -49,7 +49,7 @@ public interface PersistentPropertyAccessor {
 	 * @param property must not be {@literal null}.
 	 * @return can be {@literal null}.
 	 */
-	Optional<? extends Object> getProperty(PersistentProperty<?> property);
+	Optional<Object> getProperty(PersistentProperty<?> property);
 
 	/**
 	 * Returns the underlying bean.

src/main/java/org/springframework/data/mapping/PreferredConstructor.java

@@ -226,9 +226,11 @@ public class PreferredConstructor<T, P extends PersistentProperty<P>> {
 		}
 
 		private static Optional<String> getValue(Annotation[] annotations) {
-			return Arrays.stream(annotations).//
-					filter(it -> it.annotationType() == Value.class).//
-					findFirst().map(it -> ((Value) it).value());
+
+			return Arrays.stream(annotations)//
+					.filter(it -> it.annotationType() == Value.class)//
+					.findFirst().map(it -> ((Value) it).value())//
+					.filter(it -> StringUtils.hasText(it));
 		}
 
 		/**

src/main/java/org/springframework/data/mapping/PropertyPath.java

@@ -16,6 +16,7 @@
 package org.springframework.data.mapping;
 
 import lombok.EqualsAndHashCode;
+import lombok.Getter;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -45,7 +46,8 @@ public class PropertyPath implements Streamable<PropertyPath> {
 
 	private final TypeInformation<?> owningType;
 	private final String name;
-	private final TypeInformation<?> type;
+	private final @Getter TypeInformation<?> typeInformation;
+	private final TypeInformation<?> actualTypeInformation;
 	private final boolean isCollection;
 
 	private PropertyPath next;
@@ -57,7 +59,7 @@ public class PropertyPath implements Streamable<PropertyPath> {
 	 * @param owningType must not be {@literal null}.
 	 */
 	PropertyPath(String name, Class<?> owningType) {
-		this(name, ClassTypeInformation.from(owningType), Collections.<PropertyPath> emptyList());
+		this(name, ClassTypeInformation.from(owningType), Collections.<PropertyPath>emptyList());
 	}
 
 	/**
@@ -74,15 +76,13 @@ public class PropertyPath implements Streamable<PropertyPath> {
 		Assert.notNull(base, "Perviously found properties must not be null!");
 
 		String propertyName = name.matches(ALL_UPPERCASE) ? name : StringUtils.uncapitalize(name);
-		TypeInformation<?> propertyType = owningType.getProperty(propertyName);
-
-		if (propertyType == null) {
-			throw new PropertyReferenceException(propertyName, owningType, base);
-		}
+		TypeInformation<?> propertyType = owningType.getProperty(propertyName)
+				.orElseThrow(() -> new PropertyReferenceException(propertyName, owningType, base));
 
 		this.owningType = owningType;
+		this.typeInformation = propertyType;
 		this.isCollection = propertyType.isCollectionLike();
-		this.type = propertyType.getActualType();
+		this.actualTypeInformation = propertyType.getActualType();
 		this.name = propertyName;
 	}
 
@@ -127,7 +127,7 @@ public class PropertyPath implements Streamable<PropertyPath> {
 	 * @return
 	 */
 	public Class<?> getType() {
-		return this.type.getType();
+		return this.actualTypeInformation.getType();
 	}
 
 	/**
@@ -221,7 +221,7 @@ public class PropertyPath implements Streamable<PropertyPath> {
 		Assert.hasText(source, "Source must not be null or empty!");
 		Assert.notNull(type, "TypeInformation must not be null or empty!");
 
-		List<String> iteratorSource = new ArrayList<String>();
+		List<String> iteratorSource = new ArrayList<>();
 		Matcher matcher = SPLITTER.matcher("_" + source);
 
 		while (matcher.find()) {
@@ -231,7 +231,7 @@ public class PropertyPath implements Streamable<PropertyPath> {
 		Iterator<String> parts = iteratorSource.iterator();
 
 		PropertyPath result = null;
-		Stack<PropertyPath> current = new Stack<PropertyPath>();
+		Stack<PropertyPath> current = new Stack<>();
 
 		while (parts.hasNext()) {
 			if (result == null) {
@@ -256,7 +256,7 @@ public class PropertyPath implements Streamable<PropertyPath> {
 
 		PropertyPath previous = base.peek();
 
-		PropertyPath propertyPath = create(source, previous.type, base);
+		PropertyPath propertyPath = create(source, previous.typeInformation.getActualType(), base);
 		previous.next = propertyPath;
 		return propertyPath;
 	}
@@ -298,11 +298,11 @@ public class PropertyPath implements Streamable<PropertyPath> {
 				base.get(base.size() - 1).next = current;
 			}
 
-			List<PropertyPath> newBase = new ArrayList<PropertyPath>(base);
+			List<PropertyPath> newBase = new ArrayList<>(base);
 			newBase.add(current);
 
 			if (StringUtils.hasText(addTail)) {
-				current.next = create(addTail, current.type, newBase);
+				current.next = create(addTail, current.actualTypeInformation, newBase);
 			}
 
 			return current;

src/main/java/org/springframework/data/mapping/PropertyReferenceException.java

@@ -142,7 +142,7 @@ public class PropertyReferenceException extends RuntimeException {
 	 */
 	private static Set<String> detectPotentialMatches(String propertyName, Class<?> type) {
 
-		Set<String> result = new HashSet<String>();
+		Set<String> result = new HashSet<>();
 		result.addAll(Arrays.asList(PropertyMatches.forField(propertyName, type).getPossibleMatches()));
 		result.addAll(Arrays.asList(PropertyMatches.forProperty(propertyName, type).getPossibleMatches()));
 

src/main/java/org/springframework/data/mapping/context/AbstractMappingContext.java

@@ -29,6 +29,7 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeansException;
@@ -42,8 +43,10 @@ import org.springframework.data.mapping.model.ClassGeneratingPropertyAccessorFac
 import org.springframework.data.mapping.model.MappingException;
 import org.springframework.data.mapping.model.MutablePersistentEntity;
 import org.springframework.data.mapping.model.PersistentPropertyAccessorFactory;
+import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.data.util.ClassTypeInformation;
+import org.springframework.data.util.Optionals;
 import org.springframework.data.util.Pair;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
@@ -72,7 +75,8 @@ import org.springframework.util.StringUtils;
 public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?, P>, P extends PersistentProperty<P>>
 		implements MappingContext<E, P>, ApplicationEventPublisherAware, InitializingBean {
 
-	private final Map<TypeInformation<?>, E> persistentEntities = new HashMap<TypeInformation<?>, E>();
+	private final Optional<E> NONE = Optional.empty();
+	private final Map<TypeInformation<?>, Optional<E>> persistentEntities = new HashMap<>();
 	private final PersistentPropertyAccessorFactory persistentPropertyAccessorFactory = new ClassGeneratingPropertyAccessorFactory();
 
 	private ApplicationEventPublisher applicationEventPublisher;
@@ -132,8 +136,13 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	public Collection<E> getPersistentEntities() {
 
 		try {
+
 			read.lock();
-			return Collections.unmodifiableSet(new HashSet<E>(persistentEntities.values()));
+
+			return persistentEntities.values().stream()//
+					.flatMap(it -> Optionals.toStream(it))//
+					.collect(Collectors.toSet());
+
 		} finally {
 			read.unlock();
 		}
@@ -143,10 +152,21 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.model.MappingContext#getPersistentEntity(java.lang.Class)
 	 */
-	public E getPersistentEntity(Class<?> type) {
+	public Optional<E> getPersistentEntity(Class<?> type) {
 		return getPersistentEntity(ClassTypeInformation.from(type));
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mapping.context.MappingContext#getRequiredPersistentEntity(java.lang.Class)
+	 */
+	@Override
+	public E getRequiredPersistentEntity(Class<?> type) {
+
+		return getPersistentEntity(type).orElseThrow(
+				() -> new IllegalArgumentException(String.format("Couldn't find PersistentEntity for type %s!", type)));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.context.MappingContext#hasPersistentEntityFor(java.lang.Class)
@@ -160,13 +180,15 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.model.MappingContext#getPersistentEntity(org.springframework.data.util.TypeInformation)
 	 */
-	public E getPersistentEntity(TypeInformation<?> type) {
+	public Optional<E> getPersistentEntity(TypeInformation<?> type) {
 
 		Assert.notNull(type, "Type must not be null!");
 
 		try {
+
 			read.lock();
-			E entity = persistentEntities.get(type);
+
+			Optional<E> entity = persistentEntities.get(type);
 
 			if (entity != null) {
 				return entity;
@@ -177,7 +199,15 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 		}
 
 		if (!shouldCreatePersistentEntityFor(type)) {
-			return null;
+
+			try {
+				write.lock();
+				persistentEntities.put(type, NONE);
+			} finally {
+				write.unlock();
+			}
+
+			return NONE;
 		}
 
 		if (strict) {
@@ -189,18 +219,38 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 	/* 
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mapping.context.MappingContext#getPersistentEntity(org.springframework.data.mapping.PersistentProperty)
+	 * @see org.springframework.data.mapping.context.MappingContext#getRequiredPersistentEntity(org.springframework.data.util.TypeInformation)
 	 */
-	public E getPersistentEntity(P persistentProperty) {
+	@Override
+	public E getRequiredPersistentEntity(TypeInformation<?> type) {
 
-		if (persistentProperty == null) {
-			return null;
+		return getPersistentEntity(type)
+				.orElseThrow(() -> new MappingException(String.format("Couldn't find PersistentEntity for type %s!", type)));
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mapping.context.MappingContext#getPersistentEntity(org.springframework.data.mapping.PersistentProperty)
+	 */
+	public Optional<E> getPersistentEntity(P persistentProperty) {
+
+		Assert.notNull(persistentProperty, "PersistentProperty must not be null!");
+
 		TypeInformation<?> typeInfo = persistentProperty.getTypeInformation();
 		return getPersistentEntity(typeInfo.getActualType());
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mapping.context.MappingContext#getRequiredPersistentEntity(org.springframework.data.mapping.PersistentProperty)
+	 */
+	@Override
+	public E getRequiredPersistentEntity(P persistentProperty) {
+
+		return getPersistentEntity(persistentProperty).orElseThrow(() -> new IllegalArgumentException(
+				String.format("Couldn't find PersistentEntity for type %s!", persistentProperty)));
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.context.MappingContext#getPersistentPropertyPath(java.lang.Class, java.lang.String)
@@ -248,7 +298,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 		DefaultPersistentPropertyPath<P> path = DefaultPersistentPropertyPath.empty();
 		Iterator<String> iterator = parts.iterator();
-		E current = getPersistentEntity(type);
+		E current = getRequiredPersistentEntity(type);
 
 		while (iterator.hasNext()) {
 
@@ -277,8 +327,11 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 		Optional<P> persistentProperty = entity.getPersistentProperty(segment);
 
-		return persistentProperty.map(it -> Pair.of(path.append(it),
-				iterator.hasNext() ? getPersistentEntity(it.getTypeInformation().getActualType()) : entity));
+		return persistentProperty.map(it -> {
+
+			TypeInformation<?> type = it.getTypeInformation().getActualType();
+			return Pair.of(path.append(it), iterator.hasNext() ? getRequiredPersistentEntity(type) : entity);
+		});
 	}
 
 	/**
@@ -287,7 +340,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * @param type must not be {@literal null}.
 	 * @return
 	 */
-	protected E addPersistentEntity(Class<?> type) {
+	protected Optional<E> addPersistentEntity(Class<?> type) {
 		return addPersistentEntity(ClassTypeInformation.from(type));
 	}
 
@@ -297,7 +350,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * @param typeInformation must not be {@literal null}.
 	 * @return
 	 */
-	protected E addPersistentEntity(TypeInformation<?> typeInformation) {
+	protected Optional<E> addPersistentEntity(TypeInformation<?> typeInformation) {
 
 		Assert.notNull(typeInformation, "TypeInformation must not be null!");
 
@@ -305,11 +358,12 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 			read.lock();
 
-			E persistentEntity = persistentEntities.get(typeInformation);
+			Optional<E> persistentEntity = persistentEntities.get(typeInformation);
 
 			if (persistentEntity != null) {
 				return persistentEntity;
 			}
+
 		} finally {
 			read.unlock();
 		}
@@ -323,7 +377,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 			final E entity = createPersistentEntity(typeInformation);
 
 			// Eagerly cache the entity as we might have to find it during recursive lookups.
-			persistentEntities.put(typeInformation, entity);
+			persistentEntities.put(typeInformation, Optional.of(entity));
 
 			PropertyDescriptor[] pds = BeanUtils.getPropertyDescriptors(type);
 
@@ -354,7 +408,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 				applicationEventPublisher.publishEvent(new MappingContextEvent<E, P>(this, entity));
 			}
 
-			return entity;
+			return Optional.of(entity);
 
 		} catch (BeansException e) {
 			throw new MappingException(e.getMessage(), e);
@@ -398,8 +452,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 	 * @param simpleTypeHolder
 	 * @return
 	 */
-	protected abstract P createPersistentProperty(Optional<Field> field, PropertyDescriptor descriptor, E owner,
-			SimpleTypeHolder simpleTypeHolder);
+	protected abstract P createPersistentProperty(Property property, E owner, SimpleTypeHolder simpleTypeHolder);
 
 	/*
 	 * (non-Javadoc)
@@ -471,7 +524,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 			String fieldName = field.getName();
 
 			ReflectionUtils.makeAccessible(field);
-			createAndRegisterProperty(Optional.of(field), descriptors.get(fieldName));
+			createAndRegisterProperty(Property.of(field, Optional.ofNullable(descriptors.get(fieldName))));
 
 			this.remainingDescriptors.remove(fieldName);
 		}
@@ -486,28 +539,25 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 			for (PropertyDescriptor descriptor : remainingDescriptors.values()) {
 				if (PersistentPropertyFilter.INSTANCE.matches(descriptor)) {
-					createAndRegisterProperty(Optional.empty(), descriptor);
+					createAndRegisterProperty(Property.of(descriptor));
 				}
 			}
 		}
 
-		private void createAndRegisterProperty(Optional<Field> field, PropertyDescriptor descriptor) {
+		private void createAndRegisterProperty(Property input) {
 
-			P property = createPersistentProperty(field, descriptor, entity, simpleTypeHolder);
+			P property = createPersistentProperty(input, entity, simpleTypeHolder);
 
 			if (property.isTransient()) {
 				return;
 			}
 
-			if (field == null && !property.usePropertyAccess()) {
+			if (!input.isFieldBacked() && !property.usePropertyAccess()) {
 				return;
 			}
 
 			entity.addPersistentProperty(property);
-
-			if (property.isAssociation()) {
-				entity.addAssociation(property.getAssociation());
-			}
+			property.getAssociation().ifPresent(it -> entity.addAssociation(it));
 
 			if (entity.getType().equals(property.getRawType())) {
 				return;
@@ -533,7 +583,7 @@ public abstract class AbstractMappingContext<E extends MutablePersistentEntity<?
 
 		static {
 
-			Set<PropertyMatch> matches = new HashSet<PropertyMatch>();
+			Set<PropertyMatch> matches = new HashSet<>();
 			matches.add(new PropertyMatch("class", null));
 			matches.add(new PropertyMatch("this\\$.*", null));
 			matches.add(new PropertyMatch("metaClass", "groovy.lang.MetaClass"));

src/main/java/org/springframework/data/mapping/context/DefaultPersistentPropertyPath.java

@@ -62,7 +62,7 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 	 * @return
 	 */
 	public static <T extends PersistentProperty<T>> DefaultPersistentPropertyPath<T> empty() {
-		return new DefaultPersistentPropertyPath<T>(Collections.<T> emptyList());
+		return new DefaultPersistentPropertyPath<>(Collections.<T> emptyList());
 	}
 
 	/**
@@ -77,17 +77,17 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 		Assert.notNull(property, "Property must not be null!");
 
 		if (isEmpty()) {
-			return new DefaultPersistentPropertyPath<T>(Arrays.asList(property));
+			return new DefaultPersistentPropertyPath<>(Arrays.asList(property));
 		}
 
 		Class<?> leafPropertyType = getLeafProperty().getActualType();
 		Assert.isTrue(property.getOwner().getType().equals(leafPropertyType),
 				String.format("Cannot append property %s to type %s!", property.getName(), leafPropertyType.getName()));
 
-		List<T> properties = new ArrayList<T>(this.properties);
+		List<T> properties = new ArrayList<>(this.properties);
 		properties.add(property);
 
-		return new DefaultPersistentPropertyPath<T>(properties);
+		return new DefaultPersistentPropertyPath<>(properties);
 	}
 
 	/* 
@@ -125,7 +125,7 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 				? PropertyNameConverter.INSTANCE : converter);
 		String delimiterToUse = delimiter == null ? "." : delimiter;
 
-		List<String> result = new ArrayList<String>();
+		List<String> result = new ArrayList<>();
 
 		for (T property : properties) {
 
@@ -193,7 +193,7 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 			return this;
 		}
 
-		List<T> result = new ArrayList<T>();
+		List<T> result = new ArrayList<>();
 		Iterator<T> iterator = iterator();
 
 		for (int i = 0; i < base.getLength(); i++) {
@@ -204,7 +204,7 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 			result.add(iterator.next());
 		}
 
-		return new DefaultPersistentPropertyPath<T>(result);
+		return new DefaultPersistentPropertyPath<>(result);
 	}
 
 	/*
@@ -216,7 +216,7 @@ class DefaultPersistentPropertyPath<T extends PersistentProperty<T>> implements
 		if (size <= 1) {
 			return this;
 		}
-		return new DefaultPersistentPropertyPath<T>(properties.subList(0, size - 1));
+		return new DefaultPersistentPropertyPath<>(properties.subList(0, size - 1));
 	}
 
 	/*

src/main/java/org/springframework/data/mapping/context/MappingContext.java

@@ -16,6 +16,7 @@
 package org.springframework.data.mapping.context;
 
 import java.util.Collection;
+import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
@@ -48,7 +49,9 @@ public interface MappingContext<E extends PersistentEntity<?, P>, P extends Pers
 	 * @param type must not be {@literal null}.
 	 * @return
 	 */
-	E getPersistentEntity(Class<?> type);
+	Optional<E> getPersistentEntity(Class<?> type);
+
+	E getRequiredPersistentEntity(Class<?> type);
 
 	/**
 	 * Returns whether the {@link MappingContext} currently contains a {@link PersistentEntity} for the type.
@@ -67,25 +70,30 @@ public interface MappingContext<E extends PersistentEntity<?, P>, P extends Pers
 	 * @param type must not be {@literal null}.
 	 * @return
 	 */
-	E getPersistentEntity(TypeInformation<?> type);
+	Optional<E> getPersistentEntity(TypeInformation<?> type);
+
+	E getRequiredPersistentEntity(TypeInformation<?> type);
 
 	/**
 	 * Returns the {@link PersistentEntity} mapped by the given {@link PersistentProperty}.
 	 * 
-	 * @param persistentProperty
+	 * @param persistentProperty must not be {@literal null}.
 	 * @return the {@link PersistentEntity} mapped by the given {@link PersistentProperty} or null if no
 	 *         {@link PersistentEntity} exists for it or the {@link PersistentProperty} does not refer to an entity (the
 	 *         type of the property is considered simple see
 	 *         {@link org.springframework.data.mapping.model.SimpleTypeHolder#isSimpleType(Class)}).
 	 */
-	E getPersistentEntity(P persistentProperty);
+	Optional<E> getPersistentEntity(P persistentProperty);
+
+	E getRequiredPersistentEntity(P persistentProperty);
 
 	/**
 	 * Returns all {@link PersistentProperty}s for the given path expression based on the given {@link PropertyPath}.
 	 * 
 	 * @param propertyPath must not be {@literal null}.
 	 * @return the {@link PersistentPropertyPath} representing the given {@link PropertyPath}.
-	 * @throws InvalidPersistentPropertyPath in case not all of the segments of the given {@link PropertyPath} can be resolved.
+	 * @throws InvalidPersistentPropertyPath in case not all of the segments of the given {@link PropertyPath} can be
+	 *           resolved.
 	 */
 	PersistentPropertyPath<P> getPersistentPropertyPath(PropertyPath propertyPath);
 
@@ -100,10 +108,12 @@ public interface MappingContext<E extends PersistentEntity<?, P>, P extends Pers
 	PersistentPropertyPath<P> getPersistentPropertyPath(String propertyPath, Class<?> type);
 
 	/**
-	 * Returns the {@link PersistentPropertyPath} for the resolvable part of the given {@link InvalidPersistentPropertyPath}.
+	 * Returns the {@link PersistentPropertyPath} for the resolvable part of the given
+	 * {@link InvalidPersistentPropertyPath}.
 	 * 
 	 * @param invalidPath must not be {@literal null}.
-	 * @return the {@link PersistentPropertyPath} for the resolvable part of the given {@link InvalidPersistentPropertyPath}.
+	 * @return the {@link PersistentPropertyPath} for the resolvable part of the given
+	 *         {@link InvalidPersistentPropertyPath}.
 	 * @since 1.11
 	 */
 	PersistentPropertyPath<P> getPersistentPropertyPath(InvalidPersistentPropertyPath invalidPath);

src/main/java/org/springframework/data/mapping/context/MappingContextIsNewStrategyFactory.java

@@ -15,12 +15,15 @@
  */
 package org.springframework.data.mapping.context;
 
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.util.Arrays;
 import java.util.Optional;
+import java.util.function.Function;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
-import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.model.MappingException;
 import org.springframework.data.support.IsNewStrategy;
 import org.springframework.data.support.IsNewStrategyFactory;
@@ -69,19 +72,25 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 	@Override
 	protected IsNewStrategy doGetIsNewStrategy(Class<?> type) {
 
-		PersistentEntity<?, ?> entity = context.getPersistentEntity(type);
-
-		if (entity == null) {
-			return null;
+		return context.getPersistentEntity(type)//
+				.flatMap(it -> foo(it))//
+				.orElseThrow(() -> new MappingException(String.format("Cannot determine IsNewStrategy for type %s!", type)));
 	}
 
+	private static Optional<IsNewStrategy> foo(PersistentEntity<?, ?> entity) {
+
 		if (entity.hasVersionProperty()) {
-			return new PropertyIsNullOrZeroNumberIsNewStrategy(entity.getVersionProperty().get());
+
+			return entity.getVersionProperty().map(it -> PersistentPropertyInspectingIsNewStrategy.of(it,
+					MappingContextIsNewStrategyFactory::propertyIsNullOrZeroNumber));
+
 		} else if (entity.hasIdProperty()) {
-			return new PropertyIsNullIsNewStrategy(entity.getIdProperty().get());
-		} else {
-			throw new MappingException(String.format("Cannot determine IsNewStrategy for type %s!", type));
+
+			return entity.getIdProperty().map(
+					it -> PersistentPropertyInspectingIsNewStrategy.of(it, MappingContextIsNewStrategyFactory::propertyIsNull));
 		}
+
+		return Optional.empty();
 	}
 
 	/**
@@ -90,19 +99,11 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 	 * 
 	 * @author Oliver Gierke
 	 */
-	static abstract class PersistentPropertyInspectingIsNewStrategy implements IsNewStrategy {
-
-		private final PersistentProperty<?> property;
+	@RequiredArgsConstructor(staticName = "of")
+	static class PersistentPropertyInspectingIsNewStrategy implements IsNewStrategy {
 
-		/**
-		 * Creates a new {@link PersistentPropertyInspectingIsNewStrategy} using the given {@link PersistentProperty}.
-		 * 
-		 * @param property must not be {@literal null}.
-		 */
-		public PersistentPropertyInspectingIsNewStrategy(PersistentProperty<?> property) {
-			Assert.notNull(property, "PersistentProperty must not be null!");
-			this.property = property;
-		}
+		private final @NonNull PersistentProperty<?> property;
+		private final @NonNull Function<Optional<Object>, Boolean> isNew;
 
 		/*
 		 * (non-Javadoc)
@@ -111,80 +112,26 @@ public class MappingContextIsNewStrategyFactory extends IsNewStrategyFactorySupp
 		@Override
 		public boolean isNew(Optional<? extends Object> entity) {
 
-			return entity.map(it -> {
-
-				PersistentPropertyAccessor accessor = property.getOwner().getPropertyAccessor(it);
-				Object propertyValue = accessor.getProperty(property);
-
-				return decideIsNew(propertyValue);
-
-			}).orElse(false);
-		}
-
-		protected abstract boolean decideIsNew(Object property);
-	}
-
-	/**
-	 * {@link IsNewStrategy} that does a check against {@literal null} for the given value and considers the object new if
-	 * the value given is {@literal null}.
-	 * 
-	 * @author Oliver Gierke
-	 */
-	static class PropertyIsNullIsNewStrategy extends PersistentPropertyInspectingIsNewStrategy {
-
-		/**
-		 * Creates a new {@link PropertyIsNullIsNewStrategy} using the given {@link PersistentProperty}.
-		 * 
-		 * @param property must not be {@literal null}.
-		 */
-		public PropertyIsNullIsNewStrategy(PersistentProperty<?> property) {
-			super(property);
-		}
-
-		/* 
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mapping.model.MappingContextIsNewStrategyFactory.PersistentPropertyInspectingIsNewStrategy#decideIsNew(java.lang.Object)
-		 */
-		@Override
-		protected boolean decideIsNew(Object property) {
-			return property == null;
+			return entity//
+					.map(it -> isNew.apply(property.getOwner().getPropertyAccessor(it).getProperty(property)))//
+					.orElse(false);
 		}
 	}
 
-	/**
-	 * {@link IsNewStrategy} that considers property values of {@literal null} or 0 (in case of a {@link Number})
-	 * implementation as indicators for the new state.
-	 * 
-	 * @author Oliver Gierke
-	 */
-	static class PropertyIsNullOrZeroNumberIsNewStrategy extends PersistentPropertyInspectingIsNewStrategy {
-
-		/**
-		 * Creates a new {@link PropertyIsNullOrZeroNumberIsNewStrategy} instance using the given {@link PersistentProperty}
-		 * .
-		 * 
-		 * @param property must not be {@literal null}.
-		 */
-		public PropertyIsNullOrZeroNumberIsNewStrategy(PersistentProperty<?> property) {
-			super(property);
+	private static boolean propertyIsNull(Optional<Object> it) {
+		return !it.isPresent();
 	}
 
-		/* 
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mapping.model.MappingContextIsNewStrategyFactory.PersistentPropertyInspectingIsNewStrategy#decideIsNew(java.lang.Object)
-		 */
-		@Override
-		protected boolean decideIsNew(Object property) {
+	private static boolean propertyIsNullOrZeroNumber(Optional<Object> it) {
 
-			if (property == null) {
-				return true;
-			}
+		return it.map(value -> {
 
-			if (!(property instanceof Number)) {
+			if (!(value instanceof Number)) {
 				return false;
 			}
 
-			return ((Number) property).longValue() == 0;
-		}
+			return ((Number) value).longValue() == 0;
+
+		}).orElse(true);
 	}
 }

src/main/java/org/springframework/data/mapping/context/PersistentEntities.java

@@ -15,14 +15,12 @@
  */
 package org.springframework.data.mapping.context;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.Iterator;
-import java.util.List;
-import java.util.Set;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.data.mapping.PersistentEntity;
+import org.springframework.data.util.Streamable;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 
@@ -32,9 +30,9 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @since 1.8
  */
-public class PersistentEntities implements Iterable<PersistentEntity<?, ?>> {
+public class PersistentEntities implements Streamable<PersistentEntity<?, ?>> {
 
-	private final Iterable<? extends MappingContext<?, ?>> contexts;
+	private final Streamable<? extends MappingContext<?, ?>> contexts;
 
 	/**
 	 * Creates a new {@link PersistentEntities} for the given {@link MappingContext}s.
@@ -44,7 +42,7 @@ public class PersistentEntities implements Iterable<PersistentEntity<?, ?>> {
 	public PersistentEntities(Iterable<? extends MappingContext<?, ?>> contexts) {
 
 		Assert.notNull(contexts, "MappingContexts must not be null!");
-		this.contexts = contexts;
+		this.contexts = Streamable.of(contexts);
 	}
 
 	/**
@@ -55,16 +53,11 @@ public class PersistentEntities implements Iterable<PersistentEntity<?, ?>> {
 	 * @param type can be {@literal null}.
 	 * @return
 	 */
-	public PersistentEntity<?, ?> getPersistentEntity(Class<?> type) {
+	public Optional<PersistentEntity<?, ?>> getPersistentEntity(Class<?> type) {
 
-		for (MappingContext<?, ?> context : contexts) {
-
-			if (context.hasPersistentEntityFor(type)) {
-				return context.getPersistentEntity(type);
-			}
-		}
-
-		return null;
+		return contexts.stream()//
+				.filter(it -> it.hasPersistentEntityFor(type))//
+				.findFirst().map(it -> it.getRequiredPersistentEntity(type));
 	}
 
 	/**
@@ -72,15 +65,11 @@ public class PersistentEntities implements Iterable<PersistentEntity<?, ?>> {
 	 * 
 	 * @return
 	 */
-	public Iterable<TypeInformation<?>> getManagedTypes() {
-
-		Set<TypeInformation<?>> informations = new HashSet<TypeInformation<?>>();
+	public Streamable<TypeInformation<?>> getManagedTypes() {
 
-		for (MappingContext<?, ?> context : contexts) {
-			informations.addAll(context.getManagedTypes());
-		}
-
-		return Collections.unmodifiableSet(informations);
+		return Streamable.of(contexts.stream()//
+				.flatMap(it -> it.getManagedTypes().stream())//
+				.collect(Collectors.toSet()));
 	}
 
 	/* 
@@ -90,12 +79,7 @@ public class PersistentEntities implements Iterable<PersistentEntity<?, ?>> {
 	@Override
 	public Iterator<PersistentEntity<?, ?>> iterator() {
 
-		List<PersistentEntity<?, ?>> entities = new ArrayList<PersistentEntity<?, ?>>();
-
-		for (MappingContext<?, ?> context : contexts) {
-			entities.addAll(context.getPersistentEntities());
-		}
-
-		return entities.iterator();
+		return contexts.stream().<PersistentEntity<?, ?>>flatMap(it -> it.getPersistentEntities().stream())
+				.collect(Collectors.toList()).iterator();
 	}
 }

src/main/java/org/springframework/data/mapping/model/AbstractPersistentProperty.java

@@ -15,7 +15,9 @@
  */
 package org.springframework.data.mapping.model;
 
-import java.beans.PropertyDescriptor;
+import lombok.AccessLevel;
+import lombok.Getter;
+
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Collections;
@@ -26,6 +28,8 @@ import org.springframework.data.annotation.Reference;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.mapping.PropertyPath;
+import org.springframework.data.util.Lazy;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
@@ -46,43 +50,33 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	}
 
 	protected final String name;
-	protected final Optional<PropertyDescriptor> propertyDescriptor;
 	protected final TypeInformation<?> information;
 	protected final Class<?> rawType;
-	protected final Optional<Field> field;
-	protected final Association<P> association;
-	protected final PersistentEntity<?, P> owner;
+	protected final Optional<Association<P>> association;
+	private final @Getter PersistentEntity<?, P> owner;
+	private final @Getter(AccessLevel.PROTECTED) Property property;
 	private final SimpleTypeHolder simpleTypeHolder;
-	private final int hashCode;
+	private final Lazy<Integer> hashCode;
 
-	public AbstractPersistentProperty(Optional<Field> field, PropertyDescriptor propertyDescriptor,
-			PersistentEntity<?, P> owner, SimpleTypeHolder simpleTypeHolder) {
+	public AbstractPersistentProperty(Property property, PersistentEntity<?, P> owner,
+			SimpleTypeHolder simpleTypeHolder) {
 
 		Assert.notNull(simpleTypeHolder, "SimpleTypeHolder must not be null!");
 		Assert.notNull(owner, "Owner entity must not be null!");
 
-		this.name = field.map(Field::getName).orElseGet(() -> propertyDescriptor.getName());
-		this.rawType = field.<Class<?>> map(Field::getType).orElseGet(() -> propertyDescriptor.getPropertyType());
-		this.information = owner.getTypeInformation().getProperty(this.name);
-		this.propertyDescriptor = Optional.ofNullable(propertyDescriptor);
-		this.field = field;
-		this.association = isAssociation() ? createAssociation() : null;
+		this.name = property.getName();
+		this.rawType = property.getRawType();
+
+		this.information = PropertyPath.from(property.getName(), owner.getTypeInformation()).getTypeInformation();
+		this.property = property;
+		this.association = isAssociation() ? Optional.of(createAssociation()) : Optional.empty();
 		this.owner = owner;
 		this.simpleTypeHolder = simpleTypeHolder;
-		this.hashCode = this.field == null ? this.propertyDescriptor.hashCode() : this.field.hashCode();
+		this.hashCode = Lazy.of(() -> property.hashCode());
 	}
 
 	protected abstract Association<P> createAssociation();
 
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.data.mapping.PersistentProperty#getOwner()
-	 */
-	@Override
-	public PersistentEntity<?, P> getOwner() {
-		return owner;
-	}
-
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentProperty#getName()
@@ -131,7 +125,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 		}
 
 		TypeInformation<?> candidate = getTypeInformationIfEntityCandidate();
-		return candidate != null ? Collections.singleton(candidate) : Collections.<TypeInformation<?>> emptySet();
+		return candidate != null ? Collections.singleton(candidate) : Collections.<TypeInformation<?>>emptySet();
 	}
 
 	private TypeInformation<?> getTypeInformationIfEntityCandidate() {
@@ -151,8 +145,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public Optional<Method> getGetter() {
-		return propertyDescriptor.map(it -> it.getReadMethod())//
-				.filter(it -> rawType.isAssignableFrom(it.getReturnType()));
+		return property.getGetter();
 	}
 
 	/* 
@@ -161,8 +154,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public Optional<Method> getSetter() {
-		return propertyDescriptor.map(it -> it.getWriteMethod())//
-				.filter(it -> it.getParameterTypes()[0].isAssignableFrom(rawType));
+		return property.getSetter();
 	}
 
 	/*
@@ -171,7 +163,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public Optional<Field> getField() {
-		return field;
+		return property.getField();
 	}
 
 	/*
@@ -215,7 +207,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mapping.PersistentProperty#getAssociation()
 	 */
 	@Override
-	public Association<P> getAssociation() {
+	public Optional<Association<P>> getAssociation() {
 		return association;
 	}
 
@@ -266,8 +258,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 			return null;
 		}
 
-		TypeInformation<?> componentType = information.getComponentType();
-		return componentType == null ? null : componentType.getType();
+		return information.getRequiredComponentType().getType();
 	}
 
 	/*
@@ -276,7 +267,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public Class<?> getMapValueType() {
-		return isMap() ? information.getMapValueType().getType() : null;
+		return isMap() ? information.getMapValueType().map(it -> it.getType()).orElse(null) : null;
 	}
 
 	/* 
@@ -293,7 +284,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 * @see org.springframework.data.mongodb.core.mapping.MongoPersistentProperty#usePropertyAccess()
 	 */
 	public boolean usePropertyAccess() {
-		return owner.getType().isInterface() || CAUSE_FIELD.equals(getField());
+		return owner.getType().isInterface() || getField().map(it -> it.equals(CAUSE_FIELD)).orElse(false);
 	}
 
 	/* 
@@ -313,7 +304,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 
 		AbstractPersistentProperty<?> that = (AbstractPersistentProperty<?>) obj;
 
-		return this.field == null ? this.propertyDescriptor.equals(that.propertyDescriptor) : this.field.equals(that.field);
+		return this.property.equals(that.property);
 	}
 
 	/* 
@@ -322,7 +313,7 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public int hashCode() {
-		return this.hashCode;
+		return this.hashCode.get();
 	}
 
 	/* 
@@ -331,8 +322,6 @@ public abstract class AbstractPersistentProperty<P extends PersistentProperty<P>
 	 */
 	@Override
 	public String toString() {
-		return field.map(Object::toString)//
-				.orElseGet(() -> propertyDescriptor.map(Object::toString)//
-						.orElseThrow(() -> new IllegalStateException("Either Field or PropertyDescriptor has to be present!")));
+		return property.toString();
 	}
 }

src/main/java/org/springframework/data/mapping/model/AnnotationBasedPersistentProperty.java

@@ -15,10 +15,8 @@
  */
 package org.springframework.data.mapping.model;
 
-import java.beans.PropertyDescriptor;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.AnnotatedElement;
-import java.lang.reflect.Field;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
@@ -63,15 +61,15 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * Creates a new {@link AnnotationBasedPersistentProperty}.
 	 * 
 	 * @param field must not be {@literal null}.
-	 * @param propertyDescriptor can be {@literal null}.
+	 * @param propertyDescriptor must not be {@literal null}.
 	 * @param owner must not be {@literal null}.
 	 */
-	public AnnotationBasedPersistentProperty(Optional<Field> field, PropertyDescriptor propertyDescriptor,
-			PersistentEntity<?, P> owner, SimpleTypeHolder simpleTypeHolder) {
+	public AnnotationBasedPersistentProperty(Property property, PersistentEntity<?, P> owner,
+			SimpleTypeHolder simpleTypeHolder) {
 
-		super(field, propertyDescriptor, owner, simpleTypeHolder);
+		super(property, owner, simpleTypeHolder);
 
-		populateAnnotationCache(field);
+		populateAnnotationCache(property);
 
 		this.usePropertyAccess = findPropertyOrOwnerAnnotation(AccessType.class).map(it -> Type.PROPERTY.equals(it.value()))
 				.orElse(false);
@@ -85,9 +83,9 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	 * @param field
 	 * @throws MappingException in case we find an ambiguous mapping on the accessor methods
 	 */
-	private final void populateAnnotationCache(Optional<Field> field) {
+	private final void populateAnnotationCache(Property property) {
 
-		Optionals.toStream(getGetter(), getSetter()).forEach(it -> {
+		Optionals.toStream(property.getGetter(), property.getSetter()).forEach(it -> {
 
 			for (Annotation annotation : it.getAnnotations()) {
 
@@ -102,7 +100,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 			}
 		});
 
-		field.ifPresent(it -> {
+		property.getField().ifPresent(it -> {
 
 			for (Annotation annotation : it.getAnnotations()) {
 
@@ -218,7 +216,8 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 			return (Optional<A>) annotationCache.get(annotationType);
 		}
 
-		return cacheAndReturn(annotationType, getAccessors()//
+		return cacheAndReturn(annotationType,
+				getAccessors()//
 						.map(it -> it.map(inner -> AnnotatedElementUtils.findMergedAnnotation(inner, annotationType)))//
 						.flatMap(it -> Optionals.toStream(it))//
 						.findFirst());
@@ -232,7 +231,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	public <A extends Annotation> Optional<A> findPropertyOrOwnerAnnotation(Class<A> annotationType) {
 
 		Optional<A> annotation = findAnnotation(annotationType);
-		return annotation.isPresent() ? annotation : owner.findAnnotation(annotationType);
+		return annotation.isPresent() ? annotation : getOwner().findAnnotation(annotationType);
 	}
 
 	/**
@@ -277,7 +276,7 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	public String toString() {
 
 		if (annotationCache.isEmpty()) {
-			populateAnnotationCache(field);
+			populateAnnotationCache(getProperty());
 		}
 
 		StringBuilder builder = new StringBuilder().append(annotationCache.values().stream()//
@@ -289,6 +288,6 @@ public abstract class AnnotationBasedPersistentProperty<P extends PersistentProp
 	}
 
 	private Stream<Optional<? extends AnnotatedElement>> getAccessors() {
-		return Arrays.<Optional<? extends AnnotatedElement>> asList(getGetter(), getSetter(), getField()).stream();
+		return Arrays.<Optional<? extends AnnotatedElement>>asList(getGetter(), getSetter(), getField()).stream();
 	}
 }

src/main/java/org/springframework/data/mapping/model/BasicPersistentEntity.java

@@ -35,6 +35,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.data.annotation.TypeAlias;
+import org.springframework.data.mapping.Alias;
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.AssociationHandler;
 import org.springframework.data.mapping.IdentifierAccessor;
@@ -79,7 +80,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	private Optional<P> versionProperty = Optional.empty();
 	private PersistentPropertyAccessorFactory propertyAccessorFactory;
 
-	private final Lazy<Optional<? extends Object>> typeAlias;
+	private final Lazy<Alias> typeAlias;
 
 	/**
 	 * Creates a new {@link BasicPersistentEntity} from the given {@link TypeInformation}.
@@ -106,16 +107,17 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 		this.properties = new ArrayList<>();
 		this.comparator = comparator;
 		this.constructor = new PreferredConstructorDiscoverer<>(this).getConstructor();
-		this.associations = comparator.<Set<Association<P>>> map(it -> new TreeSet<>(new AssociationComparator<>(it)))
-				.orElse(new HashSet<>());
+		this.associations = comparator.<Set<Association<P>>>map(it -> new TreeSet<>(new AssociationComparator<>(it)))
+				.orElseGet(() -> new HashSet<>());
 
 		this.propertyCache = new HashMap<>();
 		this.annotationCache = new HashMap<>();
 		this.propertyAccessorFactory = BeanWrapperPropertyAccessorFactory.INSTANCE;
 
-		this.typeAlias = Lazy
-				.of(() -> Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(getType(), TypeAlias.class))//
-						.map(TypeAlias::value).filter(it -> StringUtils.hasText(it)));
+		this.typeAlias = Lazy.of(() -> Alias
+				.ofOptional(Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(getType(), TypeAlias.class))//
+						.map(TypeAlias::value)//
+						.filter(it -> StringUtils.hasText(it))));
 	}
 
 	/*
@@ -304,7 +306,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentEntity#getTypeAlias()
 	 */
-	public Optional<? extends Object> getTypeAlias() {
+	public Alias getTypeAlias() {
 		return typeAlias.get();
 	}
 
@@ -441,7 +443,7 @@ public class BasicPersistentEntity<T, P extends PersistentProperty<P>> implement
 		 * @see org.springframework.data.mapping.IdentifierAccessor#getIdentifier()
 		 */
 		@Override
-		public Optional<? extends Object> getIdentifier() {
+		public Optional<Object> getIdentifier() {
 			return Optional.empty();
 		}
 	}

src/main/java/org/springframework/data/mapping/model/BeanWrapper.java

@@ -80,7 +80,7 @@ class BeanWrapper<T> implements PersistentPropertyAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#getProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
-	public Optional<? extends Object> getProperty(PersistentProperty<?> property) {
+	public Optional<Object> getProperty(PersistentProperty<?> property) {
 		return getProperty(property, property.getType());
 	}
 

src/main/java/org/springframework/data/mapping/model/BeanWrapperPropertyAccessorFactory.java

@@ -33,7 +33,7 @@ enum BeanWrapperPropertyAccessorFactory implements PersistentPropertyAccessorFac
 	 */
 	@Override
 	public PersistentPropertyAccessor getPropertyAccessor(PersistentEntity<?, ?> entity, Object bean) {
-		return new BeanWrapper<Object>(bean);
+		return new BeanWrapper<>(bean);
 	}
 
 	/* 

src/main/java/org/springframework/data/mapping/model/CamelCaseSplittingFieldNamingStrategy.java

@@ -53,7 +53,7 @@ public class CamelCaseSplittingFieldNamingStrategy implements FieldNamingStrateg
 	public String getFieldName(PersistentProperty<?> property) {
 
 		List<String> parts = ParsingUtils.splitCamelCaseToLower(property.getName());
-		List<String> result = new ArrayList<String>();
+		List<String> result = new ArrayList<>();
 
 		for (String part : parts) {
 

src/main/java/org/springframework/data/mapping/model/ClassGeneratingPropertyAccessorFactory.java

@@ -64,9 +64,6 @@ import org.springframework.util.ReflectionUtils;
  */
 public class ClassGeneratingPropertyAccessorFactory implements PersistentPropertyAccessorFactory {
 
-	private static final boolean IS_JAVA_7_OR_BETTER = org.springframework.util.ClassUtils
-			.isPresent("java.lang.invoke.MethodHandle", ClassGeneratingPropertyAccessorFactory.class.getClassLoader());
-
 	private volatile Map<TypeInformation<?>, Class<PersistentPropertyAccessor>> propertyAccessorClasses = new HashMap<TypeInformation<?>, Class<PersistentPropertyAccessor>>(
 			32);
 
@@ -103,15 +100,11 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 		Assert.notNull(entity, "PersistentEntity must not be null!");
 
-		if (!IS_JAVA_7_OR_BETTER) {
-			return false;
-		}
-
 		if (entity.getType().getClassLoader() == null || entity.getType().getPackage().getName().startsWith("java")) {
 			return false;
 		}
 
-		final Set<Integer> hashCodes = new HashSet<Integer>();
+		final Set<Integer> hashCodes = new HashSet<>();
 		final AtomicInteger propertyCount = new AtomicInteger();
 
 		entity.doWithProperties(new SimplePropertyHandler() {
@@ -821,7 +814,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 			int[] hashes = new int[propertyStackMap.size()];
 			Label[] switchJumpLabels = new Label[propertyStackMap.size()];
-			List<PropertyStackAddress> stackmap = new ArrayList<PropertyStackAddress>(propertyStackMap.values());
+			List<PropertyStackAddress> stackmap = new ArrayList<>(propertyStackMap.values());
 			Collections.sort(stackmap);
 
 			for (int i = 0; i < stackmap.size(); i++) {
@@ -983,8 +976,8 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 			mv.visitLocalVariable(THIS_REF, referenceName(internalClassName), null, l0, l1, 0);
 			mv.visitLocalVariable("property", "Lorg/springframework/data/mapping/PersistentProperty;",
 					"Lorg/springframework/data/mapping/PersistentProperty<*>;", l0, l1, 1);
-			mv.visitLocalVariable("optional", referenceName(JAVA_UTIL_OPTIONAL),
-					"Ljava/util/Optional<+Ljava/lang/Object;>;", l0, l1, 2);
+			mv.visitLocalVariable("optional", referenceName(JAVA_UTIL_OPTIONAL), "Ljava/util/Optional<+Ljava/lang/Object;>;",
+					l0, l1, 2);
 
 			if (isAccessible(entity)) {
 				mv.visitLocalVariable(BEAN_FIELD, referenceName(entity.getType()), null, l0, l1, 3);
@@ -1022,7 +1015,7 @@ public class ClassGeneratingPropertyAccessorFactory implements PersistentPropert
 
 			int[] hashes = new int[propertyStackMap.size()];
 			Label[] switchJumpLabels = new Label[propertyStackMap.size()];
-			List<PropertyStackAddress> stackmap = new ArrayList<PropertyStackAddress>(propertyStackMap.values());
+			List<PropertyStackAddress> stackmap = new ArrayList<>(propertyStackMap.values());
 			Collections.sort(stackmap);
 
 			for (int i = 0; i < stackmap.size(); i++) {

src/main/java/org/springframework/data/mapping/model/ConvertingPropertyAccessor.java

@@ -65,7 +65,7 @@ public class ConvertingPropertyAccessor implements PersistentPropertyAccessor {
 	 * @see org.springframework.data.mapping.PersistentPropertyAccessor#getProperty(org.springframework.data.mapping.PersistentProperty)
 	 */
 	@Override
-	public Optional<? extends Object> getProperty(PersistentProperty<?> property) {
+	public Optional<Object> getProperty(PersistentProperty<?> property) {
 		return accessor.getProperty(property);
 	}
 

src/main/java/org/springframework/data/mapping/model/IdPropertyIdentifierAccessor.java

@@ -56,7 +56,7 @@ public class IdPropertyIdentifierAccessor implements IdentifierAccessor {
 	 * (non-Javadoc)
 	 * @see org.springframework.data.keyvalue.core.IdentifierAccessor#getIdentifier()
 	 */
-	public Optional<? extends Object> getIdentifier() {
-		return idProperty.map(it -> accessor.getProperty(it));
+	public Optional<Object> getIdentifier() {
+		return idProperty.flatMap(it -> accessor.getProperty(it));
 	}
 }

src/main/java/org/springframework/data/mapping/model/Property.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.mapping.model;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.beans.PropertyDescriptor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Optional;
+
+import org.springframework.data.util.Lazy;
+import org.springframework.util.Assert;
+
+/**
+ * @author Oliver Gierke
+ */
+@RequiredArgsConstructor
+public class Property {
+
+	private final @Getter Optional<Field> field;
+	private final Optional<PropertyDescriptor> descriptor;
+
+	private final Lazy<Class<?>> rawType;
+	private final Lazy<Integer> hashCode;
+
+	private Property(Optional<Field> field, Optional<PropertyDescriptor> descriptor) {
+
+		this.field = field;
+		this.descriptor = descriptor;
+		this.hashCode = Lazy.of(() -> computeHashCode());
+		this.rawType = Lazy
+				.of(() -> field.<Class<?>>map(Field::getType).orElseGet(() -> descriptor.map(it -> it.getPropertyType())//
+						.orElseThrow(() -> new IllegalStateException())));
+	}
+
+	public static Property of(Field field) {
+		return of(field, Optional.empty());
+	}
+
+	public static Property of(Field field, Optional<PropertyDescriptor> descriptor) {
+
+		Assert.notNull(field, "Field must not be null!");
+
+		return new Property(Optional.of(field), descriptor);
+	}
+
+	public static Property of(PropertyDescriptor descriptor) {
+
+		Assert.notNull(descriptor, "PropertyDescriptor must not be null!");
+		return new Property(Optional.empty(), Optional.of(descriptor));
+	}
+
+	public boolean isFieldBacked() {
+		return field.isPresent();
+	}
+
+	public Optional<Method> getGetter() {
+		return descriptor.map(it -> it.getReadMethod())//
+				.filter(it -> getRawType().isAssignableFrom(it.getReturnType()));
+	}
+
+	public Optional<Method> getSetter() {
+		return descriptor.map(it -> it.getWriteMethod())//
+				.filter(it -> it.getParameterTypes()[0].isAssignableFrom(getRawType()));
+	}
+
+	/**
+	 * @return
+	 */
+	public String getName() {
+		return field.map(Field::getName).orElseGet(() -> descriptor.map(it -> it.getName())//
+				.orElseThrow(() -> new IllegalStateException()));
+	}
+
+	public Class<?> getRawType() {
+		return rawType.get();
+	}
+
+	private int computeHashCode() {
+
+		return this.field.map(it -> it.hashCode())
+				.orElseGet(() -> this.descriptor.map(it -> it.hashCode()).orElseThrow(() -> new IllegalStateException()));
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see java.lang.Object#hashCode()
+	 */
+	@Override
+	public int hashCode() {
+		return hashCode.get();
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see java.lang.Object#equals(java.lang.Object)
+	 */
+	@Override
+	public boolean equals(Object obj) {
+
+		if (this == obj) {
+			return true;
+		}
+
+		if (!(obj instanceof Property)) {
+			return false;
+		}
+
+		Property that = (Property) obj;
+
+		return this.field.isPresent() ? this.field.equals(that.field) : this.descriptor.equals(that.descriptor);
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return field.map(Object::toString)
+				.orElseGet(() -> descriptor.map(Object::toString).orElseThrow(() -> new IllegalStateException()));
+	}
+}

src/main/java/org/springframework/data/mapping/model/SpELExpressionParameterValueProvider.java

@@ -62,13 +62,10 @@ public class SpELExpressionParameterValueProvider<P extends PersistentProperty<P
 	 */
 	public <T> Optional<T> getParameterValue(Parameter<T, P> parameter) {
 
-		if (!parameter.hasSpelExpression()) {
-			return delegate.getParameterValue(parameter);
-		}
-
-		Optional<Object> object = Optional.ofNullable(evaluator.evaluate(parameter.getSpelExpression().orElse(null)));
-
-		return object.map(it -> potentiallyConvertSpelValue(object, parameter));
+		return parameter.getSpelExpression()//
+				.map(it -> Optional.ofNullable(evaluator.evaluate(it))//
+						.map(result -> potentiallyConvertSpelValue(result, parameter)))
+				.orElseGet(() -> delegate.getParameterValue(parameter));
 	}
 
 	/**

src/main/java/org/springframework/data/projection/ProjectingMethodInterceptor.java

@@ -107,11 +107,11 @@ class ProjectingMethodInterceptor implements MethodInterceptor {
 				sources.size());
 
 		for (Object source : sources) {
-			result.add(getProjection(source, type.getComponentType().getType()));
+			result.add(getProjection(source, type.getRequiredComponentType().getType()));
 		}
 
 		if (rawType.isArray()) {
-			return result.toArray((Object[]) Array.newInstance(type.getComponentType().getType(), result.size()));
+			return result.toArray((Object[]) Array.newInstance(type.getRequiredComponentType().getType(), result.size()));
 		}
 
 		return result;
@@ -130,7 +130,7 @@ class ProjectingMethodInterceptor implements MethodInterceptor {
 		Map<Object, Object> result = CollectionFactory.createMap(type.getType(), sources.size());
 
 		for (Entry<?, ?> source : sources.entrySet()) {
-			result.put(source.getKey(), getProjection(source.getValue(), type.getMapValueType().getType()));
+			result.put(source.getKey(), getProjection(source.getValue(), type.getRequiredMapValueType().getType()));
 		}
 
 		return result;

src/main/java/org/springframework/data/projection/ProxyProjectionFactory.java

@@ -144,7 +144,7 @@ class ProxyProjectionFactory implements ProjectionFactory, ResourceLoaderAware,
 
 		Assert.notNull(projectionType, "Projection type must not be null!");
 
-		List<String> result = new ArrayList<String>();
+		List<String> result = new ArrayList<>();
 
 		for (PropertyDescriptor descriptor : getProjectionInformation(projectionType).getInputProperties()) {
 			result.add(descriptor.getName());

src/main/java/org/springframework/data/projection/SpelAwareProxyProjectionFactory.java

@@ -70,7 +70,7 @@ public class SpelAwareProxyProjectionFactory extends ProxyProjectionFactory impl
 
 		if (!typeCache.containsKey(projectionType)) {
 
-			AnnotationDetectionMethodCallback<Value> callback = new AnnotationDetectionMethodCallback<Value>(Value.class);
+			AnnotationDetectionMethodCallback<Value> callback = new AnnotationDetectionMethodCallback<>(Value.class);
 			ReflectionUtils.doWithMethods(projectionType, callback);
 
 			typeCache.put(projectionType, callback.hasFoundAnnotation());

src/main/java/org/springframework/data/querydsl/QPageRequest.java

@@ -17,6 +17,7 @@ package org.springframework.data.querydsl;
 
 import org.springframework.data.domain.AbstractPageRequest;
 import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
 
 import com.querydsl.core.types.OrderSpecifier;
 
@@ -39,7 +40,7 @@ public class QPageRequest extends AbstractPageRequest {
 	 * @param size
 	 */
 	public QPageRequest(int page, int size) {
-		this(page, size, (QSort) null);
+		this(page, size, QSort.unsorted());
 	}
 
 	/**
@@ -71,7 +72,7 @@ public class QPageRequest extends AbstractPageRequest {
 	 * @see org.springframework.data.domain.Pageable#getSort()
 	 */
 	@Override
-	public QSort getSort() {
+	public Sort getSort() {
 		return sort;
 	}
 
@@ -81,7 +82,7 @@ public class QPageRequest extends AbstractPageRequest {
 	 */
 	@Override
 	public Pageable next() {
-		return new QPageRequest(getPageNumber() + 1, getPageSize(), getSort());
+		return new QPageRequest(getPageNumber() + 1, getPageSize(), sort);
 	}
 
 	/* 
@@ -90,7 +91,7 @@ public class QPageRequest extends AbstractPageRequest {
 	 */
 	@Override
 	public Pageable previous() {
-		return new QPageRequest(getPageNumber() - 1, getPageSize(), getSort());
+		return new QPageRequest(getPageNumber() - 1, getPageSize(), sort);
 	}
 
 	/* 
@@ -99,6 +100,6 @@ public class QPageRequest extends AbstractPageRequest {
 	 */
 	@Override
 	public Pageable first() {
-		return new QPageRequest(0, getPageSize(), getSort());
+		return new QPageRequest(0, getPageSize(), sort);
 	}
 }

src/main/java/org/springframework/data/querydsl/QSort.java

@@ -19,6 +19,7 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Sort;
 import org.springframework.util.Assert;
@@ -36,13 +37,14 @@ import com.querydsl.core.types.Path;
 public class QSort extends Sort implements Serializable {
 
 	private static final long serialVersionUID = -6701117396842171930L;
+	private static final QSort UNSORTED = new QSort();
 
 	private final List<OrderSpecifier<?>> orderSpecifiers;
 
 	/**
 	 * Creates a new {@link QSort} instance with the given {@link OrderSpecifier}s.
 	 * 
-	 * @param orderSpecifiers must not be {@literal null} or empty.
+	 * @param orderSpecifiers must not be {@literal null} .
 	 */
 	public QSort(OrderSpecifier<?>... orderSpecifiers) {
 		this(Arrays.asList(orderSpecifiers));
@@ -51,16 +53,24 @@ public class QSort extends Sort implements Serializable {
 	/**
 	 * Creates a new {@link QSort} instance with the given {@link OrderSpecifier}s.
 	 * 
-	 * @param orderSpecifiers must not be {@literal null} or empty.
+	 * @param orderSpecifiers must not be {@literal null}.
 	 */
+
 	public QSort(List<OrderSpecifier<?>> orderSpecifiers) {
 
 		super(toOrders(orderSpecifiers));
 
-		Assert.notEmpty(orderSpecifiers, "Order specifiers must not be null or empty!");
 		this.orderSpecifiers = orderSpecifiers;
 	}
 
+	public static QSort by(OrderSpecifier<?>... orderSpecifiers) {
+		return new QSort(orderSpecifiers);
+	}
+
+	public static QSort unsorted() {
+		return UNSORTED;
+	}
+
 	/**
 	 * Converts the given {@link OrderSpecifier}s into a list of {@link Order}s.
 	 * 
@@ -69,14 +79,9 @@ public class QSort extends Sort implements Serializable {
 	 */
 	private static List<Order> toOrders(List<OrderSpecifier<?>> orderSpecifiers) {
 
-		Assert.notEmpty(orderSpecifiers, "Order specifiers must not be null or empty!");
-
-		List<Order> orders = new ArrayList<Sort.Order>();
-		for (OrderSpecifier<?> orderSpecifier : orderSpecifiers) {
-			orders.add(toOrder(orderSpecifier));
-		}
+		Assert.notNull(orderSpecifiers, "Order specifiers must not be null!");
 
-		return orders;
+		return orderSpecifiers.stream().map(QSort::toOrder).collect(Collectors.toList());
 	}
 
 	/**

src/main/java/org/springframework/data/querydsl/QuerydslRepositoryInvokerAdapter.java

@@ -59,7 +59,7 @@ public class QuerydslRepositoryInvokerAdapter implements RepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeFindAll(org.springframework.data.domain.Pageable)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokePagedFindAll(org.springframework.data.domain.Pageable)
 	 */
 	@Override
 	public Iterable<Object> invokeFindAll(Pageable pageable) {
@@ -68,7 +68,7 @@ public class QuerydslRepositoryInvokerAdapter implements RepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeFindAll(org.springframework.data.domain.Sort)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeSortedFindAll(org.springframework.data.domain.Sort)
 	 */
 	@Override
 	public Iterable<Object> invokeFindAll(Sort sort) {

src/main/java/org/springframework/data/querydsl/binding/MultiValueBinding.java

@@ -38,8 +38,8 @@ public interface MultiValueBinding<T extends Path<? extends S>, S> {
 	 * 
 	 * @param path {@link Path} to the property. Will not be {@literal null}.
 	 * @param value the value that should be bound. Will not be {@literal null} or empty.
-	 * @return can be {@literal null}, in which case the binding will not be incorporated in the overall {@link Predicate}
-	 *         .
+	 * @return can be {@literal null}, in which case the binding will not be incorporated in the overall
+	 *         {@link Predicate}.
 	 */
 	Optional<Predicate> bind(T path, Collection<? extends S> value);
 }

src/main/java/org/springframework/data/querydsl/binding/QuerydslBindings.java

@@ -81,9 +81,9 @@ public class QuerydslBindings {
 
 		this.pathSpecs = new LinkedHashMap<String, PathAndBinding<?, ?>>();
 		this.typeSpecs = new LinkedHashMap<Class<?>, PathAndBinding<?, ?>>();
-		this.whiteList = new HashSet<String>();
-		this.blackList = new HashSet<String>();
-		this.aliases = new HashSet<String>();
+		this.whiteList = new HashSet<>();
+		this.blackList = new HashSet<>();
+		this.aliases = new HashSet<>();
 
 	}
 
@@ -115,7 +115,7 @@ public class QuerydslBindings {
 	 * @return
 	 */
 	public final <T> TypeBinder<T> bind(Class<T> type) {
-		return new TypeBinder<T>(type);
+		return new TypeBinder<>(type);
 	}
 
 	/**
@@ -502,7 +502,7 @@ public class QuerydslBindings {
 
 			Assert.notNull(binding, "Binding must not be null!");
 
-			QuerydslBindings.this.typeSpecs.put(type, PathAndBinding.<T, P> withoutPath().with(binding));
+			QuerydslBindings.this.typeSpecs.put(type, PathAndBinding.<T, P>withoutPath().with(binding));
 		}
 	}
 

src/main/java/org/springframework/data/querydsl/binding/QuerydslPredicateBuilder.java

@@ -148,7 +148,37 @@ public class QuerydslPredicateBuilder {
 
 		Optional<Path<?>> resolvedPath = bindings.getExistingPath(path);
 
-		return resolvedPath.orElseGet(() -> paths.computeIfAbsent(path, it -> path.reifyPath(resolver)));
+		return resolvedPath.orElseGet(() -> paths.computeIfAbsent(path, it -> reifyPath(path, Optional.empty())));
+	}
+
+	/**
+	 * Tries to reify a Querydsl {@link Path} from the given {@link PropertyPath} and base.
+	 * 
+	 * @param path must not be {@literal null}.
+	 * @param base can be empty.
+	 * @return
+	 */
+	private Path<?> reifyPath(PropertyPath path, Optional<Path<?>> base) {
+
+		Optional<Path<?>> map = base.filter(it -> it instanceof CollectionPathBase)
+				.map(it -> CollectionPathBase.class.cast(it))//
+				.map(CollectionPathBase::any)//
+				.map(it -> Path.class.cast(it))//
+				.map(it -> reifyPath(path, Optional.of(it)));
+
+		return map.orElseGet(() -> {
+
+			Path<?> entityPath = base.orElseGet(() -> resolver.createPath(path.getOwningType().getType()));
+
+			Field field = ReflectionUtils.findField(entityPath.getClass(), path.getSegment());
+			Object value = ReflectionUtils.getField(field, entityPath);
+
+			if (path.hasNext()) {
+				return reifyPath(path.next(), Optional.of((Path<?>) value));
+			}
+
+			return (Path<?>) value;
+		});
 	}
 
 	/**
@@ -162,13 +192,13 @@ public class QuerydslPredicateBuilder {
 	 */
 	private Collection<Object> convertToPropertyPathSpecificType(List<String> source, PathInformation path) {
 
-		Class<?> targetType = path.getLeafType();
+		Class<?> targetType = path.getLeafProperty().getType();
 
 		if (source.isEmpty() || isSingleElementCollectionWithoutText(source)) {
 			return Collections.emptyList();
 		}
 
-		Collection<Object> target = new ArrayList<Object>(source.size());
+		Collection<Object> target = new ArrayList<>(source.size());
 
 		for (String value : source) {
 

src/main/java/org/springframework/data/repository/PagingAndSortingRepository.java

@@ -47,5 +47,5 @@ public interface PagingAndSortingRepository<T, ID extends Serializable> extends
 	 * @param pageable
 	 * @return a page of entities
 	 */
-	Page<T> findAll(Pageable pageable);
+	<S extends Sort> Page<T> findAll(Pageable pageable);
 }

src/main/java/org/springframework/data/repository/cdi/CdiRepositoryBean.java

@@ -110,7 +110,7 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	 */
 	private final String createPassivationId(Set<Annotation> qualifiers, Class<?> repositoryType) {
 
-		List<String> qualifierNames = new ArrayList<String>(qualifiers.size());
+		List<String> qualifierNames = new ArrayList<>(qualifiers.size());
 
 		for (Annotation qualifier : qualifiers) {
 			qualifierNames.add(qualifier.annotationType().getName());
@@ -131,11 +131,11 @@ public abstract class CdiRepositoryBean<T> implements Bean<T>, PassivationCapabl
 	@SuppressWarnings("rawtypes")
 	public Set<Type> getTypes() {
 
-		Set<Class> interfaces = new HashSet<Class>();
+		Set<Class> interfaces = new HashSet<>();
 		interfaces.add(repositoryType);
 		interfaces.addAll(Arrays.asList(repositoryType.getInterfaces()));
 
-		return new HashSet<Type>(interfaces);
+		return new HashSet<>(interfaces);
 	}
 
 	/**

src/main/java/org/springframework/data/repository/cdi/CdiRepositoryExtensionSupport.java

@@ -119,7 +119,7 @@ public abstract class CdiRepositoryExtensionSupport implements Extension {
 	 */
 	private Set<Annotation> getQualifiers(final Class<?> type) {
 
-		Set<Annotation> qualifiers = new HashSet<Annotation>();
+		Set<Annotation> qualifiers = new HashSet<>();
 		Annotation[] annotations = type.getAnnotations();
 		for (Annotation annotation : annotations) {
 			Class<? extends Annotation> annotationType = annotation.annotationType();

src/main/java/org/springframework/data/repository/config/AnnotationRepositoryConfigurationSource.java

@@ -124,7 +124,7 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 			return Collections.singleton(ClassUtils.getPackageName(className));
 		}
 
-		Set<String> packages = new HashSet<String>();
+		Set<String> packages = new HashSet<>();
 		packages.addAll(Arrays.asList(value));
 		packages.addAll(Arrays.asList(basePackages));
 
@@ -187,7 +187,7 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 
 	private Set<TypeFilter> parseFilters(String attributeName) {
 
-		Set<TypeFilter> result = new HashSet<TypeFilter>();
+		Set<TypeFilter> result = new HashSet<>();
 		AnnotationAttributes[] filters = attributes.getAnnotationArray(attributeName);
 
 		for (AnnotationAttributes filter : filters) {
@@ -259,7 +259,7 @@ public class AnnotationRepositoryConfigurationSource extends RepositoryConfigura
 	 */
 	private List<TypeFilter> typeFiltersFor(AnnotationAttributes filterAttributes) {
 
-		List<TypeFilter> typeFilters = new ArrayList<TypeFilter>();
+		List<TypeFilter> typeFilters = new ArrayList<>();
 		FilterType filterType = filterAttributes.getEnum("type");
 
 		for (Class<?> filterClass : filterAttributes.getClassArray("value")) {

src/main/java/org/springframework/data/repository/config/CustomRepositoryImplementationDetector.java

@@ -94,7 +94,7 @@ public class CustomRepositoryImplementationDetector {
 			provider.addExcludeFilter(excludeFilter);
 		}
 
-		Set<BeanDefinition> definitions = new HashSet<BeanDefinition>();
+		Set<BeanDefinition> definitions = new HashSet<>();
 
 		for (String basePackage : basePackages) {
 			definitions.addAll(provider.findCandidateComponents(basePackage));

src/main/java/org/springframework/data/repository/config/RepositoryBeanDefinitionBuilder.java

@@ -89,7 +89,8 @@ class RepositoryBeanDefinitionBuilder {
 		builder.addConstructorArgValue(configuration.getRepositoryInterface());
 		builder.addPropertyValue("queryLookupStrategyKey", configuration.getQueryLookupStrategyKey());
 		builder.addPropertyValue("lazyInit", configuration.isLazyInit());
-		builder.addPropertyValue("repositoryBaseClass", configuration.getRepositoryBaseClassName());
+		builder.addPropertyValue("repositoryBaseClass",
+				configuration.getRepositoryBaseClassName().orElseGet(() -> extension.getRepositoryFactoryClassName()));
 
 		NamedQueriesBeanDefinitionBuilder definitionBuilder = new NamedQueriesBeanDefinitionBuilder(
 				extension.getDefaultNamedQueryLocation());

src/main/java/org/springframework/data/repository/config/RepositoryComponentProvider.java

@@ -85,13 +85,13 @@ class RepositoryComponentProvider extends ClassPathScanningCandidateComponentPro
 	@Override
 	public void addIncludeFilter(TypeFilter includeFilter) {
 
-		List<TypeFilter> filterPlusInterface = new ArrayList<TypeFilter>(2);
+		List<TypeFilter> filterPlusInterface = new ArrayList<>(2);
 		filterPlusInterface.add(includeFilter);
 		filterPlusInterface.add(new InterfaceTypeFilter(Repository.class));
 
 		super.addIncludeFilter(new AllTypeFilter(filterPlusInterface));
 
-		List<TypeFilter> filterPlusAnnotation = new ArrayList<TypeFilter>(2);
+		List<TypeFilter> filterPlusAnnotation = new ArrayList<>(2);
 		filterPlusAnnotation.add(includeFilter);
 		filterPlusAnnotation.add(new AnnotationTypeFilter(RepositoryDefinition.class, true, true));
 

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationDelegate.java

@@ -117,7 +117,7 @@ public class RepositoryConfigurationDelegate {
 
 		RepositoryBeanDefinitionBuilder builder = new RepositoryBeanDefinitionBuilder(registry, extension, resourceLoader,
 				environment);
-		List<BeanComponentDefinition> definitions = new ArrayList<BeanComponentDefinition>();
+		List<BeanComponentDefinition> definitions = new ArrayList<>();
 
 		for (RepositoryConfiguration<? extends RepositoryConfigurationSource> configuration : extension
 				.getRepositoryConfigurations(configurationSource, resourceLoader, inMultiStoreMode)) {

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationExtensionSupport.java

@@ -239,7 +239,7 @@ public abstract class RepositoryConfigurationExtensionSupport implements Reposit
 	 */
 	protected <T extends RepositoryConfigurationSource> RepositoryConfiguration<T> getRepositoryConfiguration(
 			BeanDefinition definition, T configSource) {
-		return new DefaultRepositoryConfiguration<T>(configSource, definition);
+		return new DefaultRepositoryConfiguration<>(configSource, definition);
 	}
 
 	/**

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationSourceSupport.java

@@ -65,7 +65,7 @@ public abstract class RepositoryConfigurationSourceSupport implements Repository
 			scanner.addExcludeFilter(filter);
 		}
 
-		Set<BeanDefinition> result = new HashSet<BeanDefinition>();
+		Set<BeanDefinition> result = new HashSet<>();
 
 		for (String basePackage : getBasePackages()) {
 			Set<BeanDefinition> candidate = scanner.findCandidateComponents(basePackage);

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

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.core;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 /**
  * Extension of {@link EntityMetadata} to add functionality to query information of entity instances.
@@ -38,7 +39,7 @@ public interface EntityInformation<T, ID extends Serializable> extends EntityMet
 	 * @param entity must never be {@literal null}
 	 * @return
 	 */
-	ID getId(T entity);
+	Optional<ID> getId(T entity);
 
 	/**
 	 * Returns the type of the id of the entity.

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

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.core.support;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 import org.springframework.data.repository.core.EntityInformation;
 import org.springframework.util.Assert;
@@ -48,18 +49,22 @@ public abstract class AbstractEntityInformation<T, ID extends Serializable> impl
 	 */
 	public boolean isNew(T entity) {
 
-		ID id = getId(entity);
+		Optional<ID> id = getId(entity);
 		Class<ID> idType = getIdType();
 
 		if (!idType.isPrimitive()) {
-			return id == null;
+			return !id.isPresent();
 		}
 
-		if (id instanceof Number) {
-			return ((Number) id).longValue() == 0L;
+		return id.map(it -> {
+
+			if (it instanceof Number) {
+				return ((Number) it).longValue() == 0L;
 			}
 
-		throw new IllegalArgumentException(String.format("Unsupported primitive id type %s!", idType));
+			return null;
+
+		}).orElseThrow(() -> new IllegalArgumentException(String.format("Unsupported primitive id type %s!", idType)));
 	}
 
 	/*

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

@@ -149,6 +149,6 @@ public abstract class AbstractRepositoryMetadata implements RepositoryMetadata {
 		boolean needToUnwrap = Iterable.class.isAssignableFrom(rawType) || rawType.isArray()
 				|| QueryExecutionConverters.supports(rawType) || ReflectionUtils.isJava8StreamType(rawType);
 
-		return needToUnwrap ? unwrapWrapperTypes(type.getComponentType()) : rawType;
+		return needToUnwrap ? unwrapWrapperTypes(type.getRequiredComponentType()) : rawType;
 	}
 }

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

@@ -76,8 +76,9 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	public DefaultRepositoryInformation(RepositoryMetadata metadata, Class<?> repositoryBaseClass,
 			Optional<Class<?>> customImplementationClass) {
 
-		Assert.notNull(metadata, "Metadata must not be null!");
-		Assert.notNull(repositoryBaseClass, "RepositoryBaseClass must not be null!");
+		Assert.notNull(metadata, "Repository metadata must not be null!");
+		Assert.notNull(repositoryBaseClass, "Repository base class must not be null!");
+		Assert.notNull(customImplementationClass, "Custom implementation class must not be null!");
 
 		this.metadata = metadata;
 		this.repositoryBaseClass = repositoryBaseClass;
@@ -162,7 +163,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	@Override
 	public Streamable<Method> getQueryMethods() {
 
-		Set<Method> result = new HashSet<Method>();
+		Set<Method> result = new HashSet<>();
 
 		for (Method method : getRepositoryInterface().getMethods()) {
 			method = ClassUtils.getMostSpecificMethod(method, getRepositoryInterface());

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

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.core.support;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 import org.springframework.data.repository.core.EntityInformation;
 import org.springframework.util.Assert;
@@ -62,7 +63,7 @@ public class DelegatingEntityInformation<T, ID extends Serializable> implements
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.core.EntityInformation#getId(java.lang.Object)
 	 */
-	public ID getId(T entity) {
+	public Optional<ID> getId(T entity) {
 		return delegate.getId(entity);
 	}
 

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

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.core.support;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.data.domain.Persistable;
@@ -27,8 +28,8 @@ import org.springframework.data.repository.core.EntityMetadata;
  * 
  * @author Oliver Gierke
  */
-public class PersistableEntityInformation<T extends Persistable<ID>, ID extends Serializable> extends
-		AbstractEntityInformation<T, ID> {
+public class PersistableEntityInformation<T extends Persistable<ID>, ID extends Serializable>
+		extends AbstractEntityInformation<T, ID> {
 
 	private Class<ID> idClass;
 
@@ -46,32 +47,27 @@ public class PersistableEntityInformation<T extends Persistable<ID>, ID extends
 
 	/*
 	 * (non-Javadoc)
-			 *
-			 * @see
-			 * org.springframework.data.repository.support.IsNewAware#isNew(java.lang
-			 * .Object)
+	 * @see org.springframework.data.repository.core.support.AbstractEntityInformation#isNew(java.lang.Object)
 	 */
 	@Override
 	public boolean isNew(T entity) {
-
 		return entity.isNew();
 	}
 
 	/*
 	 * (non-Javadoc)
-			 *
-			 * @see
-			 * org.springframework.data.repository.support.IdAware#getId(java.lang.Object
-			 * )
+	 * @see org.springframework.data.repository.core.EntityInformation#getId(java.lang.Object)
 	 */
-	public ID getId(T entity) {
-
-		return entity.getId();
+	@Override
+	public Optional<ID> getId(T entity) {
+		return Optional.ofNullable(entity.getId());
 	}
 
-	/* (non-Javadoc)
-			 * @see org.springframework.data.repository.support.EntityInformation#getIdType()
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.repository.core.EntityInformation#getIdType()
 	 */
+	@Override
 	public Class<ID> getIdType() {
 		return this.idClass;
 	}

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

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.core.support;
 
 import java.io.Serializable;
+import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.repository.core.EntityInformation;
@@ -47,8 +48,8 @@ public class PersistentEntityInformation<T, ID extends Serializable> extends Abs
 	 * @see org.springframework.data.repository.core.EntityInformation#getId(java.lang.Object)
 	 */
 	@Override
-	public ID getId(T entity) {
-		return (ID) persistentEntity.getIdentifierAccessor(entity).getIdentifier().orElse(null);
+	public Optional<ID> getId(T entity) {
+		return persistentEntity.getIdentifierAccessor(entity).getIdentifier().map(it -> (ID) it);
 	}
 
 	/* 

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

@@ -18,13 +18,12 @@ package org.springframework.data.repository.core.support;
 import java.io.Serializable;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
+import java.util.Optional;
 
 import org.springframework.data.annotation.Id;
 import org.springframework.data.repository.core.EntityInformation;
-import org.springframework.data.repository.core.support.AbstractEntityInformation;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
-import org.springframework.util.ReflectionUtils.FieldCallback;
 
 /**
  * {@link EntityInformation} implementation that inspects fields for an annotation and looks up this field's value to
@@ -60,13 +59,11 @@ public class ReflectionEntityInformation<T, ID extends Serializable> extends Abs
 		super(domainClass);
 		Assert.notNull(annotation, "Annotation must not be null!");
 
-		ReflectionUtils.doWithFields(domainClass, new FieldCallback() {
-			public void doWith(Field field) {
+		ReflectionUtils.doWithFields(domainClass, field -> {
 			if (field.getAnnotation(annotation) != null) {
 				ReflectionEntityInformation.this.field = field;
 				return;
 			}
-			}
 		});
 
 		Assert.notNull(this.field, String.format("No field annotated with %s found!", annotation.toString()));
@@ -78,8 +75,8 @@ public class ReflectionEntityInformation<T, ID extends Serializable> extends Abs
 	 * @see org.springframework.data.repository.core.EntityInformation#getId(java.lang.Object)
 	 */
 	@SuppressWarnings("unchecked")
-	public ID getId(Object entity) {
-		return entity == null ? null : (ID) ReflectionUtils.getField(field, entity);
+	public Optional<ID> getId(Object entity) {
+		return entity == null ? null : Optional.of((ID) ReflectionUtils.getField(field, entity));
 	}
 
 	/* 

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

@@ -199,9 +199,8 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	 */
 	public PersistentEntity<?, ?> getPersistentEntity() {
 
-		return mappingContext//
-				.map(context -> context.getPersistentEntity(repositoryMetadata.getDomainType()))//
-				.orElseGet(null);
+		return mappingContext.orElseThrow(() -> new IllegalStateException("No MappingContext available!"))
+				.getRequiredPersistentEntity(repositoryMetadata.getDomainType());
 	}
 
 	/* (non-Javadoc)

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

@@ -40,8 +40,8 @@ import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
-import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor;
 import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
@@ -73,8 +73,6 @@ import org.springframework.util.Assert;
  */
 public abstract class RepositoryFactorySupport implements BeanClassLoaderAware, BeanFactoryAware {
 
-	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;
@@ -197,6 +195,19 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 		return getRepository(repositoryInterface, Optional.empty());
 	}
 
+	/**
+	 * Returns a repository instance for the given interface backed by an instance providing implementation logic for
+	 * custom logic.
+	 * 
+	 * @param <T>
+	 * @param repositoryInterface
+	 * @param customImplementation
+	 * @return
+	 */
+	public <T> T getRepository(Class<T> repositoryInterface, Object customImplementation) {
+		return getRepository(repositoryInterface, Optional.of(customImplementation));
+	}
+
 	/**
 	 * Returns a repository instance for the given interface backed by an instance providing implementation logic for
 	 * custom logic.
@@ -207,7 +218,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @return
 	 */
 	@SuppressWarnings({ "unchecked" })
-	public <T> T getRepository(Class<T> repositoryInterface, Optional<Object> customImplementation) {
+	protected <T> T getRepository(Class<T> repositoryInterface, Optional<Object> customImplementation) {
 
 		RepositoryMetadata metadata = getRepositoryMetadata(repositoryInterface);
 		RepositoryInformation information = getRepositoryInformation(metadata, customImplementation.map(Object::getClass));
@@ -230,10 +241,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 
 		postProcessors.forEach(processor -> processor.postProcess(result, information));
 
-		if (IS_JAVA_8) {
 		result.addAdvice(new DefaultMethodInvokingMethodInterceptor());
-		}
-
 		result.addAdvice(new QueryExecutorMethodInterceptor(information));
 
 		result.addAdvice(information.isReactiveRepository()
@@ -265,15 +273,14 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 
 		RepositoryInformationCacheKey cacheKey = new RepositoryInformationCacheKey(metadata, customImplementationClass);
 
-		return repositoryInformationCache.computeIfAbsent(cacheKey, key -> new DefaultRepositoryInformation(metadata,
-				repositoryBaseClass.orElse(getRepositoryBaseClass(metadata)), customImplementationClass));
+		return repositoryInformationCache.computeIfAbsent(cacheKey, key -> {
 
-		/*
-		repositoryInformation = metadata.isReactiveRepository()
-						? new ReactiveRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass)
-						: new DefaultRepositoryInformation(metadata, repositoryBaseClass, customImplementationClass);
-		*/
+			Class<?> baseClass = repositoryBaseClass.orElse(getRepositoryBaseClass(metadata));
 
+			return metadata.isReactiveRepository()
+					? new ReactiveRepositoryInformation(metadata, baseClass, customImplementationClass)
+					: new DefaultRepositoryInformation(metadata, baseClass, customImplementationClass);
+		});
 	}
 
 	protected List<QueryMethod> getQueryMethods() {
@@ -432,9 +439,11 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 		private void invokeListeners(RepositoryQuery query) {
 
 			for (QueryCreationListener listener : queryPostProcessors) {
-				Class<?> typeArgument = GenericTypeResolver.resolveTypeArgument(listener.getClass(),
-						QueryCreationListener.class);
-				if (typeArgument != null && typeArgument.isAssignableFrom(query.getClass())) {
+
+				ResolvableType typeArgument = ResolvableType.forClass(QueryCreationListener.class, listener.getClass())
+						.getGeneric(0);
+
+				if (typeArgument != null && typeArgument.isAssignableFrom(ResolvableType.forClass(query.getClass()))) {
 					listener.onCreation(query);
 				}
 			}
@@ -620,7 +629,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 		/**
 		 * All {@link QueryMethod}s.
 		 */
-		private List<QueryMethod> queryMethods = new ArrayList<QueryMethod>();
+		private List<QueryMethod> queryMethods = new ArrayList<>();
 
 		/* (non-Javadoc)
 		 * @see org.springframework.data.repository.core.support.QueryCreationListener#onCreation(org.springframework.data.repository.query.RepositoryQuery)

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

@@ -157,7 +157,7 @@ class TransactionalRepositoryProxyPostProcessor implements RepositoryProxyPostPr
 		 */
 		public CustomAnnotationTransactionAttributeSource(boolean publicMethodsOnly) {
 			this.publicMethodsOnly = publicMethodsOnly;
-			this.annotationParsers = new LinkedHashSet<TransactionAnnotationParser>(2);
+			this.annotationParsers = new LinkedHashSet<>(2);
 			this.annotationParsers.add(new SpringTransactionAnnotationParser());
 			if (jta12Present) {
 				this.annotationParsers.add(new JtaTransactionAnnotationParser());
@@ -186,7 +186,7 @@ class TransactionalRepositoryProxyPostProcessor implements RepositoryProxyPostPr
 		public CustomAnnotationTransactionAttributeSource(TransactionAnnotationParser... annotationParsers) {
 			this.publicMethodsOnly = true;
 			Assert.notEmpty(annotationParsers, "At least one TransactionAnnotationParser needs to be specified");
-			Set<TransactionAnnotationParser> parsers = new LinkedHashSet<TransactionAnnotationParser>(
+			Set<TransactionAnnotationParser> parsers = new LinkedHashSet<>(
 					annotationParsers.length);
 			Collections.addAll(parsers, annotationParsers);
 			this.annotationParsers = parsers;

src/main/java/org/springframework/data/repository/init/Jackson2ResourceReader.java

@@ -80,12 +80,12 @@ public class Jackson2ResourceReader implements ResourceReader {
 	public Object readFrom(Resource resource, ClassLoader classLoader) throws Exception {
 
 		InputStream stream = resource.getInputStream();
-		JsonNode node = mapper.reader(JsonNode.class).readTree(stream);
+		JsonNode node = mapper.readerFor(JsonNode.class).readTree(stream);
 
 		if (node.isArray()) {
 
 			Iterator<JsonNode> elements = node.elements();
-			List<Object> result = new ArrayList<Object>();
+			List<Object> result = new ArrayList<>();
 
 			while (elements.hasNext()) {
 				JsonNode element = elements.next();
@@ -112,6 +112,6 @@ public class Jackson2ResourceReader implements ResourceReader {
 
 		Class<?> type = ClassUtils.resolveClassName(typeName, classLoader);
 
-		return mapper.reader(type).readValue(node);
+		return mapper.readerFor(type).readValue(node);
 	}
 }

src/main/java/org/springframework/data/repository/query/EvaluationContextExtensionInformation.java

@@ -91,7 +91,7 @@ class EvaluationContextExtensionInformation {
 	 */
 	public RootObjectInformation getRootObjectInformation(Optional<Object> target) {
 
-		return target.map(it -> rootObjectInformation.orElse(new RootObjectInformation(it.getClass())))
+		return target.map(it -> rootObjectInformation.orElseGet(() -> new RootObjectInformation(it.getClass())))
 				.orElse(RootObjectInformation.NONE);
 	}
 
@@ -215,8 +215,8 @@ class EvaluationContextExtensionInformation {
 			Assert.notNull(type, "Type must not be null!");
 
 			this.accessors = new HashMap<String, Method>();
-			this.methods = new HashSet<Method>();
-			this.fields = new ArrayList<Field>();
+			this.methods = new HashSet<>();
+			this.fields = new ArrayList<>();
 
 			if (Object.class.equals(type)) {
 				return;
@@ -232,7 +232,7 @@ class EvaluationContextExtensionInformation {
 						.filter(it -> method.equals(it.getReadMethod()))//
 						.forEach(it -> RootObjectInformation.this.accessors.put(it.getName(), method));
 
-			} , PublicMethodAndFieldFilter.NON_STATIC);
+			}, PublicMethodAndFieldFilter.NON_STATIC);
 
 			ReflectionUtils.doWithFields(type, field -> RootObjectInformation.this.fields.add(field),
 					PublicMethodAndFieldFilter.NON_STATIC);
@@ -250,7 +250,7 @@ class EvaluationContextExtensionInformation {
 					.collect(Collectors.toMap(//
 							Method::getName, //
 							method -> new Function(method, it))))
-					.orElse(Collections.emptyMap());
+					.orElseGet(() -> Collections.emptyMap());
 		}
 
 		/**
@@ -271,7 +271,7 @@ class EvaluationContextExtensionInformation {
 
 				return Collections.unmodifiableMap(properties);
 
-			}).orElse(Collections.emptyMap());
+			}).orElseGet(() -> Collections.emptyMap());
 		}
 	}
 

src/main/java/org/springframework/data/repository/query/ExtensionAwareEvaluationContextProvider.java

@@ -163,7 +163,7 @@ public class ExtensionAwareEvaluationContextProvider implements EvaluationContex
 		this.extensions = Collections.emptyList();
 
 		beanFactory.ifPresent(it -> {
-			this.extensions = new ArrayList<EvaluationContextExtension>(
+			this.extensions = new ArrayList<>(
 					it.getBeansOfType(EvaluationContextExtension.class, true, false).values());
 		});
 

src/main/java/org/springframework/data/repository/query/ParameterAccessor.java

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.query;
 
 import java.util.Iterator;
+import java.util.Optional;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -48,7 +49,7 @@ public interface ParameterAccessor extends Iterable<Object> {
 	 * @return
 	 * @since 1.12
 	 */
-	Class<?> getDynamicProjection();
+	Optional<Class<?>> getDynamicProjection();
 
 	/**
 	 * Returns the bindable value with the given index. Bindable means, that {@link Pageable} and {@link Sort} values are

src/main/java/org/springframework/data/repository/query/Parameters.java

@@ -64,7 +64,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 
 		List<Class<?>> types = Arrays.asList(method.getParameterTypes());
 
-		this.parameters = new ArrayList<T>(types.size());
+		this.parameters = new ArrayList<>(types.size());
 		this.dynamicProjectionIndex = -1;
 
 		for (int i = 0; i < types.size(); i++) {
@@ -98,7 +98,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 	 */
 	protected Parameters(List<T> originals) {
 
-		this.parameters = new ArrayList<T>(originals.size());
+		this.parameters = new ArrayList<>(originals.size());
 
 		int pageableIndexTemp = -1;
 		int sortIndexTemp = -1;
@@ -251,7 +251,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 	 */
 	public S getBindableParameters() {
 
-		List<T> bindables = new ArrayList<T>();
+		List<T> bindables = new ArrayList<>();
 
 		for (T candidate : this) {
 

src/main/java/org/springframework/data/repository/query/ParametersParameterAccessor.java

@@ -18,6 +18,7 @@ package org.springframework.data.repository.query;
 import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 import org.springframework.data.domain.Pageable;
@@ -70,10 +71,12 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	public Pageable getPageable() {
 
 		if (!parameters.hasPageableParameter()) {
-			return null;
+			return Pageable.NONE;
 		}
 
-		return (Pageable) values.get(parameters.getPageableIndex());
+		Pageable pageable = (Pageable) values.get(parameters.getPageableIndex());
+
+		return pageable == null ? Pageable.NONE : pageable;
 	}
 
 	/*
@@ -83,14 +86,16 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	public Sort getSort() {
 
 		if (parameters.hasSortParameter()) {
-			return (Sort) values.get(parameters.getSortIndex());
+
+			Sort sort = (Sort) values.get(parameters.getSortIndex());
+			return sort == null ? Sort.unsorted() : sort;
 		}
 
-		if (parameters.hasPageableParameter() && getPageable() != null) {
+		if (parameters.hasPageableParameter()) {
 			return getPageable().getSort();
 		}
 
-		return null;
+		return Sort.unsorted();
 	}
 
 	/**
@@ -98,8 +103,9 @@ public class ParametersParameterAccessor implements ParameterAccessor {
 	 * 
 	 * @return
 	 */
-	public Class<?> getDynamicProjection() {
-		return parameters.hasDynamicProjection() ? (Class<?>) values.get(parameters.getDynamicProjectionIndex()) : null;
+	public Optional<Class<?>> getDynamicProjection() {
+		return Optional.ofNullable(
+				parameters.hasDynamicProjection() ? (Class<?>) values.get(parameters.getDynamicProjectionIndex()) : null);
 	}
 
 	/**

src/main/java/org/springframework/data/repository/query/QueryMethod.java

@@ -265,7 +265,9 @@ public class QueryMethod {
 
 		if (QueryExecutionConverters.supports(method.getReturnType())) {
 			// unwrap only one level to handle cases like Future<List<Entity>> correctly.
-			return ClassTypeInformation.fromReturnTypeOf(method).getComponentType().getType();
+			return ClassTypeInformation.fromReturnTypeOf(method).getComponentType().map(it -> it.getType())
+					.orElseThrow(() -> new IllegalStateException(
+							String.format("Couldn't find component type for return value of method %s!", method)));
 		}
 
 		return method.getReturnType();

src/main/java/org/springframework/data/repository/query/ResultProcessor.java

@@ -23,6 +23,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Stream;
 
 import org.springframework.core.CollectionFactory;
@@ -48,8 +49,7 @@ public class ResultProcessor {
 	private final QueryMethod method;
 	private final ProjectingConverter converter;
 	private final ProjectionFactory factory;
-
-	private ReturnedType type;
+	private final ReturnedType type;
 
 	/**
 	 * Creates a new {@link ResultProcessor} from the given {@link QueryMethod} and {@link ProjectionFactory}.
@@ -86,15 +86,11 @@ public class ResultProcessor {
 	 * @param accessor can be {@literal null}.
 	 * @return
 	 */
-	public ResultProcessor withDynamicProjection(ParameterAccessor accessor) {
-
-		if (accessor == null) {
-			return this;
-		}
+	public ResultProcessor withDynamicProjection(Optional<ParameterAccessor> accessor) {
 
-		Class<?> projectionType = accessor.getDynamicProjection();
-
-		return projectionType == null ? this : new ResultProcessor(method, factory, projectionType);
+		return accessor.flatMap(it -> it.getDynamicProjection())//
+				.map(it -> new ResultProcessor(method, factory, it))//
+				.orElse(this);
 	}
 
 	/**
@@ -280,34 +276,4 @@ public class ResultProcessor {
 			return result;
 		}
 	}
-
-	/**
-	 * Handler for Repository query methods returning a Java 8 Stream result by ensuring the {@link Stream} elements match
-	 * the expected return type of the query method.
-	 *
-	 * @author John Blum
-	 * @author Oliver Gierke
-	 */
-	@RequiredArgsConstructor
-	static class StreamQueryResultHandler {
-
-		private final @NonNull ReturnedType returnType;
-		private final @NonNull Converter<Object, Object> converter;
-
-		/**
-		 * Processes the given source object as a {@link Stream}, mapping each element to the required return type,
-		 * converting if necessary.
-		 *
-		 * @param source the {@link Stream} of elements to process, must not be {@literal null}.
-		 * @return a new {@link Stream} with the source {@link Stream}'s elements mapped to the target type.
-		 */
-		@SuppressWarnings("unchecked")
-		public Object handle(Object source) {
-
-			Assert.isInstanceOf(Stream.class, source, "Source must not be null and an instance of Stream!");
-
-			return ((Stream<Object>) source)
-					.map(element -> returnType.isInstance(element) ? element : converter.convert(element));
-		}
-	}
 }

src/main/java/org/springframework/data/repository/query/ReturnedType.java

@@ -189,7 +189,7 @@ public abstract class ReturnedType {
 		@Override
 		public List<String> getInputProperties() {
 
-			List<String> properties = new ArrayList<String>();
+			List<String> properties = new ArrayList<>();
 
 			for (PropertyDescriptor descriptor : information.getInputProperties()) {
 				if (!properties.contains(descriptor.getName())) {
@@ -291,7 +291,7 @@ public abstract class ReturnedType {
 						.flatMap(parameter -> Optionals.toStream(parameter.getName()))//
 						.collect(Collectors.toList());
 
-			}).orElse(Collections.emptyList());
+			}).orElseGet(() -> Collections.emptyList());
 		}
 
 		private boolean isDto() {

src/main/java/org/springframework/data/repository/query/parser/AbstractQueryCreator.java

@@ -68,9 +68,7 @@ public abstract class AbstractQueryCreator<T, S> {
 	 * @return
 	 */
 	public T createQuery() {
-
-		Sort dynamicSort = parameters != null ? parameters.getSort() : null;
-		return createQuery(dynamicSort);
+		return createQuery(parameters.getSort());
 	}
 
 	/**
@@ -82,10 +80,7 @@ public abstract class AbstractQueryCreator<T, S> {
 	 */
 	public T createQuery(Sort dynamicSort) {
 
-		Sort staticSort = tree.getSort();
-		Sort sort = staticSort != null ? staticSort.and(dynamicSort) : dynamicSort;
-
-		return complete(createCriteria(tree), sort);
+		return complete(createCriteria(tree), tree.getSort().and(dynamicSort));
 	}
 
 	/**

src/main/java/org/springframework/data/repository/query/parser/OrderBySource.java

@@ -39,10 +39,12 @@ import org.springframework.util.StringUtils;
  */
 class OrderBySource {
 
+	public static OrderBySource EMPTY = new OrderBySource("");
+
 	private static final String BLOCK_SPLIT = "(?<=Asc|Desc)(?=\\p{Lu})";
 	private static final Pattern DIRECTION_SPLIT = Pattern.compile("(.+?)(Asc|Desc)?$");
 	private static final String INVALID_ORDER_SYNTAX = "Invalid order syntax for part %s!";
-	private static final Set<String> DIRECTION_KEYWORDS = new HashSet<String>(Arrays.asList("Asc", "Desc"));
+	private static final Set<String> DIRECTION_KEYWORDS = new HashSet<>(Arrays.asList("Asc", "Desc"));
 
 	private final List<Order> orders;
 
@@ -53,7 +55,7 @@ class OrderBySource {
 	 * @param clause must not be {@literal null}.
 	 */
 	public OrderBySource(String clause) {
-		this(clause, null);
+		this(clause, Optional.empty());
 	}
 
 	/**
@@ -61,12 +63,16 @@ class OrderBySource {
 	 * type.
 	 * 
 	 * @param clause must not be {@literal null}.
-	 * @param domainClass can be {@literal null}.
+	 * @param domainClass must not be {@literal null}.
 	 */
-	public OrderBySource(String clause, Class<?> domainClass) {
+	public OrderBySource(String clause, Optional<Class<?>> domainClass) {
 
 		this.orders = new ArrayList<Sort.Order>();
 
+		if (!StringUtils.hasText(clause)) {
+			return;
+		}
+
 		for (String part : clause.split(BLOCK_SPLIT)) {
 
 			Matcher matcher = DIRECTION_SPLIT.matcher(part);
@@ -83,8 +89,7 @@ class OrderBySource {
 				throw new IllegalArgumentException(String.format(INVALID_ORDER_SYNTAX, part));
 			}
 
-			Direction direction = StringUtils.hasText(directionString) ? Direction.fromString(directionString) : null;
-			this.orders.add(createOrder(propertyString, direction, domainClass));
+			this.orders.add(createOrder(propertyString, Direction.fromOptionalString(directionString), domainClass));
 		}
 	}
 
@@ -98,13 +103,17 @@ class OrderBySource {
 	 * @return
 	 * @see PropertyPath#from(String, Class)
 	 */
-	private Order createOrder(String propertySource, Direction direction, Class<?> domainClass) {
+	private Order createOrder(String propertySource, Optional<Direction> direction, Optional<Class<?>> domainClass) {
 
-		if (null == domainClass) {
-			return new Order(direction, StringUtils.uncapitalize(propertySource));
-		}
-		PropertyPath propertyPath = PropertyPath.from(propertySource, domainClass);
-		return new Order(direction, propertyPath.toDotPath());
+		return domainClass.map(type -> {
+
+			PropertyPath propertyPath = PropertyPath.from(propertySource, type);
+			return direction.map(it -> new Order(it, propertyPath.toDotPath()))
+					.orElseGet(() -> new Order(propertyPath.toDotPath()));
+
+		}).orElseGet(() -> direction//
+				.map(it -> new Order(it, StringUtils.uncapitalize(propertySource)))
+				.orElseGet(() -> new Order(StringUtils.uncapitalize(propertySource))));
 	}
 
 	/**
@@ -112,8 +121,8 @@ class OrderBySource {
 	 * 
 	 * @return the {@link Sort}.
 	 */
-	public Optional<Sort> toSort() {
-		return this.orders.isEmpty() ? Optional.empty() : Optional.of(new Sort(this.orders));
+	public Sort toSort() {
+		return Sort.by(this.orders);
 	}
 
 	/*

src/main/java/org/springframework/data/repository/query/parser/Part.java

@@ -169,7 +169,7 @@ public class Part {
 		public static final Collection<String> ALL_KEYWORDS;
 
 		static {
-			List<String> allKeywords = new ArrayList<String>();
+			List<String> allKeywords = new ArrayList<>();
 			for (Type type : ALL) {
 				allKeywords.addAll(type.keywords);
 			}

src/main/java/org/springframework/data/repository/query/parser/PartTree.java

@@ -110,7 +110,7 @@ public class PartTree implements Streamable<OrPart> {
 	 * @return the sort
 	 */
 	public Sort getSort() {
-		return predicate.getOrderBySource().flatMap(OrderBySource::toSort).orElse(null);
+		return predicate.getOrderBySource().toSort();
 	}
 
 	/**
@@ -193,12 +193,15 @@ public class PartTree implements Streamable<OrPart> {
 				.collect(Collectors.toList()));
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see java.lang.Object#toString()
+	 */
 	@Override
 	public String toString() {
 
-		Optional<OrderBySource> orderBySource = predicate.getOrderBySource();
-		return String.format("%s%s", StringUtils.collectionToDelimitedString(predicate.nodes, " or "),
-				orderBySource.map(it -> " ".concat(it.toString())).orElse(""));
+		return String.format("%s %s", StringUtils.collectionToDelimitedString(predicate.nodes, " or "),
+				predicate.getOrderBySource().toString()).trim();
 	}
 
 	/**
@@ -347,13 +350,13 @@ public class PartTree implements Streamable<OrPart> {
 	 * @author Oliver Gierke
 	 * @author Phil Webb
 	 */
-	private static class Predicate implements Iterable<OrPart> {
+	private static class Predicate implements Streamable<OrPart> {
 
 		private static final Pattern ALL_IGNORE_CASE = Pattern.compile("AllIgnor(ing|e)Case");
 		private static final String ORDER_BY = "OrderBy";
 
 		private final List<OrPart> nodes;
-		private final @Getter Optional<OrderBySource> orderBySource;
+		private final @Getter OrderBySource orderBySource;
 		private boolean alwaysIgnoreCase;
 
 		public Predicate(String predicate, Class<?> domainClass) {
@@ -368,7 +371,8 @@ public class PartTree implements Streamable<OrPart> {
 					.map(part -> new OrPart(part, domainClass, alwaysIgnoreCase))//
 					.collect(Collectors.toList());
 
-			this.orderBySource = Optional.ofNullable(parts.length == 2 ? new OrderBySource(parts[1], domainClass) : null);
+			this.orderBySource = parts.length == 2 ? new OrderBySource(parts[1], Optional.of(domainClass))
+					: OrderBySource.EMPTY;
 		}
 
 		private String detectAndSetAllIgnoreCase(String predicate) {

src/main/java/org/springframework/data/repository/support/CrudRepositoryInvoker.java

@@ -88,7 +88,7 @@ class CrudRepositoryInvoker extends ReflectionRepositoryInvoker {
 	@Override
 	@SuppressWarnings("unchecked")
 	public <T> T invokeFindOne(Serializable id) {
-		return customFindOneMethod ? super.<T> invokeFindOne(id) : (T) repository.findOne(convertId(id));
+		return customFindOneMethod ? super.<T>invokeFindOne(id) : (T) repository.findOne(convertId(id));
 	}
 
 	/*

src/main/java/org/springframework/data/repository/support/DefaultRepositoryInvokerFactory.java

@@ -18,11 +18,14 @@ package org.springframework.data.repository.support;
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.core.convert.ConversionService;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.data.repository.core.RepositoryInformation;
+import org.springframework.data.util.Optionals;
+import org.springframework.data.util.Pair;
 import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.util.Assert;
 
@@ -84,11 +87,13 @@ public class DefaultRepositoryInvokerFactory implements RepositoryInvokerFactory
 	 */
 	private RepositoryInvoker prepareInvokers(Class<?> domainType) {
 
-		Object repository = repositories.getRepositoryFor(domainType);
-		Assert.notNull(repository, String.format("No repository found for domain type: %s", domainType));
-		RepositoryInformation information = repositories.getRepositoryInformationFor(domainType);
+		Optional<Pair<Object, RepositoryInformation>> repositoryAndInformation = Optionals
+				.withBoth(repositories.getRepositoryFor(domainType), repositories.getRepositoryInformationFor(domainType));
 
-		return createInvoker(information, repository);
+		return repositoryAndInformation//
+				.map(it -> createInvoker(it.getSecond(), it.getFirst())) //
+				.orElseThrow(
+						() -> new IllegalArgumentException(String.format("No repository found for domain type: %s", domainType)));
 	}
 
 	@SuppressWarnings("unchecked")

src/main/java/org/springframework/data/repository/support/DomainClassConverter.java

@@ -16,6 +16,7 @@
 package org.springframework.data.repository.support;
 
 import java.util.Collections;
+import java.util.Optional;
 import java.util.Set;
 
 import org.springframework.context.ApplicationContext;
@@ -150,11 +151,12 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 			}
 
 			Class<?> domainType = targetType.getType();
-
-			RepositoryInformation info = repositories.getRepositoryInformationFor(domainType);
 			RepositoryInvoker invoker = repositoryInvokerFactory.getInvokerFor(domainType);
 
-			return invoker.invokeFindOne(conversionService.convert(source, info.getIdType()));
+			return repositories.getRepositoryInformationFor(domainType)//
+					.map(it -> invoker.invokeFindOne(conversionService.convert(source, it.getIdType())))//
+					.orElseThrow(() -> new IllegalStateException(
+							String.format("Couldn't find RepositoryInformation for %s!", domainType)));
 		}
 
 		/*
@@ -168,14 +170,22 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 				return false;
 			}
 
-			if (!repositories.hasRepositoryFor(targetType.getType())) {
+			Class<?> domainType = targetType.getType();
+
+			if (!repositories.hasRepositoryFor(domainType)) {
 				return false;
 			}
 
-			Class<?> rawIdType = repositories.getRepositoryInformationFor(targetType.getType()).getIdType();
+			Optional<RepositoryInformation> repositoryInformation = repositories.getRepositoryInformationFor(domainType);
+
+			return repositoryInformation.map(it -> {
+
+				Class<?> rawIdType = it.getIdType();
 
 				return sourceType.equals(TypeDescriptor.valueOf(rawIdType))
 						|| conversionService.canConvert(sourceType.getType(), rawIdType);
+			}).orElseThrow(
+					() -> new IllegalStateException(String.format("Couldn't find RepositoryInformation for %s!", domainType)));
 		}
 	}
 
@@ -229,14 +239,23 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 				return false;
 			}
 
-			if (!repositories.hasRepositoryFor(sourceType.getType())) {
+			Class<?> domainType = sourceType.getType();
+
+			if (!repositories.hasRepositoryFor(domainType)) {
 				return false;
 			}
 
-			Class<?> rawIdType = repositories.getRepositoryInformationFor(sourceType.getType()).getIdType();
+			Optional<RepositoryInformation> information = repositories.getRepositoryInformationFor(domainType);
+
+			return information.map(it -> {
+
+				Class<?> rawIdType = it.getIdType();
 
 				return targetType.equals(TypeDescriptor.valueOf(rawIdType))
 						|| conversionService.canConvert(rawIdType, targetType.getType());
+
+			}).orElseThrow(
+					() -> new IllegalStateException(String.format("Couldn't find RepositoryInformation for %s!", domainType)));
 		}
 	}
 }

src/main/java/org/springframework/data/repository/support/MethodParameters.java

@@ -19,10 +19,13 @@ import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 import org.springframework.core.DefaultParameterNameDiscoverer;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterNameDiscoverer;
+import org.springframework.data.util.Lazy;
 import org.springframework.util.Assert;
 
 /**
@@ -42,7 +45,7 @@ class MethodParameters {
 	 * @param method must not be {@literal null}.
 	 */
 	public MethodParameters(Method method) {
-		this(method, null);
+		this(method, Optional.empty());
 	}
 
 	/**
@@ -50,12 +53,12 @@ class MethodParameters {
 	 * is given, method parameter names will be looked up from the annotation attribute if present.
 	 * 
 	 * @param method must not be {@literal null}.
-	 * @param namingAnnotation can be {@literal null}.
+	 * @param namingAnnotation must not be {@literal null}.
 	 */
-	public MethodParameters(Method method, AnnotationAttribute namingAnnotation) {
+	public MethodParameters(Method method, Optional<AnnotationAttribute> namingAnnotation) {
 
 		Assert.notNull(method, "Method must not be null!");
-		this.parameters = new ArrayList<MethodParameter>();
+		this.parameters = new ArrayList<>();
 
 		for (int i = 0; i < method.getParameterTypes().length; i++) {
 
@@ -80,17 +83,12 @@ class MethodParameters {
 	 * @param name must not be {@literal null} or empty.
 	 * @return
 	 */
-	public MethodParameter getParameter(String name) {
+	public Optional<MethodParameter> getParameter(String name) {
 
 		Assert.hasText(name, "Parameter name must not be null!");
 
-		for (MethodParameter parameter : parameters) {
-			if (name.equals(parameter.getParameterName())) {
-				return parameter;
-			}
-		}
-
-		return null;
+		return getParameters().stream()//
+				.filter(it -> name.equals(it.getParameterName())).findFirst();
 	}
 
 	/**
@@ -103,15 +101,10 @@ class MethodParameters {
 	public List<MethodParameter> getParametersOfType(Class<?> type) {
 
 		Assert.notNull(type, "Type must not be null!");
-		List<MethodParameter> result = new ArrayList<MethodParameter>();
-
-		for (MethodParameter parameter : getParameters()) {
-			if (parameter.getParameterType().equals(type)) {
-				result.add(parameter);
-			}
-		}
 
-		return result;
+		return getParameters().stream()//
+				.filter(it -> it.getParameterType().equals(type))//
+				.collect(Collectors.toList());
 	}
 
 	/**
@@ -123,15 +116,10 @@ class MethodParameters {
 	public List<MethodParameter> getParametersWith(Class<? extends Annotation> annotation) {
 
 		Assert.notNull(annotation, "Annotation must not be null!");
-		List<MethodParameter> result = new ArrayList<MethodParameter>();
-
-		for (MethodParameter parameter : getParameters()) {
-			if (parameter.hasParameterAnnotation(annotation)) {
-				result.add(parameter);
-			}
-		}
 
-		return result;
+		return getParameters().stream()//
+				.filter(it -> it.hasParameterAnnotation(annotation))//
+				.collect(Collectors.toList());
 	}
 
 	/**
@@ -142,8 +130,8 @@ class MethodParameters {
 	 */
 	private static class AnnotationNamingMethodParameter extends MethodParameter {
 
-		private final AnnotationAttribute attribute;
-		private String name;
+		private final Optional<AnnotationAttribute> attribute;
+		private final Lazy<String> name;
 
 		/**
 		 * Creates a new {@link AnnotationNamingMethodParameter} for the given {@link Method}'s parameter with the given
@@ -153,11 +141,17 @@ class MethodParameters {
 		 * @param parameterIndex
 		 * @param attribute can be {@literal null}
 		 */
-		public AnnotationNamingMethodParameter(Method method, int parameterIndex, AnnotationAttribute attribute) {
+		public AnnotationNamingMethodParameter(Method method, int parameterIndex, Optional<AnnotationAttribute> attribute) {
 
 			super(method, parameterIndex);
+
 			this.attribute = attribute;
+			this.name = Lazy.of(() -> {
 
+				return this.attribute.//
+						flatMap(it -> it.getValueFrom(this).map(Object::toString)).//
+						orElseGet(() -> super.getParameterName());
+			});
 		}
 
 		/* 
@@ -166,21 +160,7 @@ class MethodParameters {
 		 */
 		@Override
 		public String getParameterName() {
-
-			if (name != null) {
-				return name;
-			}
-
-			if (attribute != null) {
-				Object foundName = attribute.getValueFrom(this);
-				if (foundName != null) {
-					name = foundName.toString();
-					return name;
-				}
-			}
-
-			name = super.getParameterName();
-			return name;
+			return name.get();
 		}
 	}
 }