DATACMNS-944 - Moved to more consistent naming scheme for CrudRepository methods.

We now follow a more consistent naming scheme for the methods in repository that are driven by the following guidelines:

* Methods referring to an identifier now all end on …ById(…).
* Methods taking or returning a collection are named …All(…)

That results in the following renames:

* findOne(…) -> findById(…)
* save(Iterable) -> saveAll(Iterable)
* findAll(Iterable<ID>) -> findAllById(…)
* delete(ID) -> deleteById(ID)
* delete(Iterable<T>) -> deleteAll(Iterable<T>)
* exists() -> existsById(…)

As a side-effect of that, we can now drop the Serializable requirement for identifiers.

Updated CRUD method detection to use the new naming scheme and moved the code to Java 8 streams and Optional. Adapted RepositoryInvoker API to reflect method name changes as well.

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.domain;
 
-import java.io.Serializable;
 import java.time.temporal.TemporalAccessor;
 import java.util.Optional;
 
@@ -27,7 +26,7 @@ import java.util.Optional;
  * @param <ID> the type of the audited type's identifier
  * @author Oliver Gierke
  */
-public interface Auditable<U, ID extends Serializable, T extends TemporalAccessor> extends Persistable<ID> {
+public interface Auditable<U, ID, T extends TemporalAccessor> extends Persistable<ID> {
 
 	/**
 	 * Returns the user who created this entity.

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

@@ -15,15 +15,13 @@
  */
 package org.springframework.data.domain;
 
-import java.io.Serializable;
-
 /**
  * Simple interface for entities.
  * 
  * @param <ID> the type of the identifier
  * @author Oliver Gierke
  */
-public interface Persistable<ID extends Serializable> extends Serializable {
+public interface Persistable<ID> {
 
 	/**
 	 * Returns the id of the entity.

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.querydsl;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -114,20 +113,20 @@ public class QuerydslRepositoryInvokerAdapter implements RepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeDelete(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeDeleteById(java.lang.Object)
 	 */
 	@Override
-	public void invokeDelete(Serializable id) {
-		delegate.invokeDelete(id);
+	public void invokeDeleteById(Object id) {
+		delegate.invokeDeleteById(id);
 	}
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeFindOne(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeFindById(java.lang.Object)
 	 */
 	@Override
-	public <T> Optional<T> invokeFindOne(Serializable id) {
-		return delegate.invokeFindOne(id);
+	public <T> Optional<T> invokeFindById(Object id) {
+		return delegate.invokeFindById(id);
 	}
 
 	/*

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2011 the original author or authors.
+ * Copyright 2008-2017 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.
@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository;
 
-import java.io.Serializable;
 import java.util.Optional;
 
 /**
@@ -25,43 +24,43 @@ import java.util.Optional;
  * @author Eberhard Wolff
  */
 @NoRepositoryBean
-public interface CrudRepository<T, ID extends Serializable> extends Repository<T, ID> {
+public interface CrudRepository<T, ID> extends Repository<T, ID> {
 
 	/**
 	 * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
 	 * entity instance completely.
 	 * 
-	 * @param entity
-	 * @return the saved entity
+	 * @param entity must not be {@literal null}.
+	 * @return the saved entity will never be {@literal null}.
 	 */
 	<S extends T> S save(S entity);
 
 	/**
 	 * Saves all given entities.
 	 * 
-	 * @param entities
-	 * @return the saved entities
+	 * @param entities must not be {@literal null}.
+	 * @return the saved entities will never be {@literal null}.
 	 * @throws IllegalArgumentException in case the given entity is {@literal null}.
 	 */
-	<S extends T> Iterable<S> save(Iterable<S> entities);
+	<S extends T> Iterable<S> saveAll(Iterable<S> entities);
 
 	/**
 	 * Retrieves an entity by its id.
 	 * 
 	 * @param id must not be {@literal null}.
-	 * @return the entity with the given id or {@literal null} if none found
-	 * @throws IllegalArgumentException if {@code id} is {@literal null}
+	 * @return the entity with the given id or {@literal Optional#empty()} if none found
+	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Optional<T> findOne(ID id);
+	Optional<T> findById(ID id);
 
 	/**
 	 * Returns whether an entity with the given id exists.
 	 * 
 	 * @param id must not be {@literal null}.
-	 * @return true if an entity with the given id exists, {@literal false} otherwise
-	 * @throws IllegalArgumentException if {@code id} is {@literal null}
+	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
+	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	boolean exists(ID id);
+	boolean existsById(ID id);
 
 	/**
 	 * Returns all instances of the type.
@@ -76,7 +75,7 @@ public interface CrudRepository<T, ID extends Serializable> extends Repository<T
 	 * @param ids
 	 * @return
 	 */
-	Iterable<T> findAll(Iterable<ID> ids);
+	Iterable<T> findAllById(Iterable<ID> ids);
 
 	/**
 	 * Returns the number of entities available.
@@ -91,7 +90,7 @@ public interface CrudRepository<T, ID extends Serializable> extends Repository<T
 	 * @param id must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@code id} is {@literal null}
 	 */
-	void delete(ID id);
+	void deleteById(ID id);
 
 	/**
 	 * Deletes a given entity.
@@ -107,7 +106,7 @@ public interface CrudRepository<T, ID extends Serializable> extends Repository<T
 	 * @param entities
 	 * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
 	 */
-	void delete(Iterable<? extends T> entities);
+	void deleteAll(Iterable<? extends T> entities);
 
 	/**
 	 * Deletes all entities managed by the repository.

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

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.repository;
 
-import java.io.Serializable;
-
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -31,7 +29,7 @@ import org.springframework.data.domain.Sort;
  * @see Page
  */
 @NoRepositoryBean
-public interface PagingAndSortingRepository<T, ID extends Serializable> extends CrudRepository<T, ID> {
+public interface PagingAndSortingRepository<T, ID> extends CrudRepository<T, ID> {
 
 	/**
 	 * Returns all entities sorted by the given options.

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

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.repository;
 
-import java.io.Serializable;
-
 import org.springframework.stereotype.Indexed;
 
 /**
@@ -33,6 +31,6 @@ import org.springframework.stereotype.Indexed;
  * @author Oliver Gierke
  */
 @Indexed
-public interface Repository<T, ID extends Serializable> {
+public interface Repository<T, ID> {
 
 }

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository;
 
-import java.io.Serializable;
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
@@ -53,5 +52,5 @@ public @interface RepositoryDefinition {
 	 * @see Repository
 	 * @return
 	 */
-	Class<? extends Serializable> idClass();
+	Class<?> idClass();
 }

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

@@ -65,7 +65,7 @@ public interface CrudMethods {
 
 	/**
 	 * Returns the find one method of the repository. Usually signature compatible to
-	 * {@link CrudRepository#findOne(java.io.Serializable)}
+	 * {@link CrudRepository#findById(Object)}
 	 * 
 	 * @return the find one method of the repository or {@literal null} if not available.
 	 * @see #hasFindOneMethod()

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core;
 
-import java.io.Serializable;
 import java.util.Optional;
 
 import org.springframework.util.Assert;
@@ -25,7 +24,7 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public interface EntityInformation<T, ID extends Serializable> extends EntityMetadata<T> {
+public interface EntityInformation<T, ID> extends EntityMetadata<T> {
 
 	/**
 	 * Returns whether the given entity is considered to be new.
@@ -49,6 +48,7 @@ public interface EntityInformation<T, ID extends Serializable> extends EntityMet
 	 * @param entity must not be {@literal null}.
 	 * @return the identifier of the given entity
 	 * @throws IllegalArgumentException in case no id could be obtained from the given entity
+	 * @since 2.0
 	 */
 	default ID getRequiredId(T entity) throws IllegalArgumentException {
 

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.Set;
@@ -34,7 +33,7 @@ public interface RepositoryMetadata {
 	 * 
 	 * @return the id class of the entity managed by the repository for or {@code null} if none found.
 	 */
-	Class<? extends Serializable> getIdType();
+	Class<?> getIdType();
 
 	/**
 	 * Returns the domain class the repository is declared for.

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

@@ -15,11 +15,12 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.util.Optional;
 
 import org.springframework.data.repository.core.EntityInformation;
-import org.springframework.util.Assert;
 
 /**
  * Base class for implementations of {@link EntityInformation}. Considers an entity to be new whenever
@@ -28,20 +29,10 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @author Nick Williams
  */
-public abstract class AbstractEntityInformation<T, ID extends Serializable> implements EntityInformation<T, ID> {
-
-	private final Class<T> domainClass;
+@RequiredArgsConstructor
+public abstract class AbstractEntityInformation<T, ID> implements EntityInformation<T, ID> {
 
-	/**
-	 * Creates a new {@link AbstractEntityInformation} from the given domain class.
-	 * 
-	 * @param domainClass must not be {@literal null}.
-	 */
-	public AbstractEntityInformation(Class<T> domainClass) {
-
-		Assert.notNull(domainClass, "DomainClass must not be null!");
-		this.domainClass = domainClass;
-	}
+	private final @NonNull Class<T> domainClass;
 
 	/*
 	 * (non-Javadoc)

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

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
-
 import org.springframework.data.repository.RepositoryDefinition;
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.util.Assert;
@@ -33,7 +31,7 @@ public class AnnotationRepositoryMetadata extends AbstractRepositoryMetadata {
 	private static final String NO_ANNOTATION_FOUND = String.format("Interface must be annotated with @%s!",
 			RepositoryDefinition.class.getName());
 
-	private final Class<? extends Serializable> idType;
+	private final Class<?> idType;
 	private final Class<?> domainType;
 
 	/**
@@ -56,7 +54,7 @@ public class AnnotationRepositoryMetadata extends AbstractRepositoryMetadata {
 	 * @see org.springframework.data.repository.core.RepositoryMetadata#getIdType()
 	 */
 	@Override
-	public Class<? extends Serializable> getIdType() {
+	public Class<?> getIdType() {
 		return this.idType;
 	}
 
@@ -69,7 +67,7 @@ public class AnnotationRepositoryMetadata extends AbstractRepositoryMetadata {
 		return this.domainType;
 	}
 
-	private Class<? extends Serializable> resolveIdType(Class<?> repositoryInterface) {
+	private Class<?> resolveIdType(Class<?> repositoryInterface) {
 
 		RepositoryDefinition annotation = repositoryInterface.getAnnotation(RepositoryDefinition.class);
 

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

@@ -16,19 +16,21 @@
 package org.springframework.data.repository.core.support;
 
 import static java.util.Arrays.*;
-import static org.springframework.util.ClassUtils.*;
-import static org.springframework.util.ReflectionUtils.*;
+import static org.springframework.data.util.Optionals.*;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
 
+import org.springframework.core.BridgeMethodResolver;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.CrudRepository;
-import org.springframework.data.repository.PagingAndSortingRepository;
 import org.springframework.data.repository.core.CrudMethods;
 import org.springframework.data.repository.core.RepositoryMetadata;
+import org.springframework.data.util.Optionals;
+import org.springframework.data.util.Pair;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
@@ -44,10 +46,12 @@ import org.springframework.util.ReflectionUtils;
  */
 public class DefaultCrudMethods implements CrudMethods {
 
-	private static final String FIND_ONE = "findOne";
+	private static final String FIND_ONE = "findById";
 	private static final String SAVE = "save";
 	private static final String FIND_ALL = "findAll";
+
 	private static final String DELETE = "delete";
+	private static final String DELETE_BY_ID = "deleteById";
 
 	private final Optional<Method> findAllMethod;
 	private final Optional<Method> findOneMethod;
@@ -79,18 +83,12 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	private Optional<Method> selectMostSuitableSaveMethod(RepositoryMetadata metadata) {
-
-		for (Class<?> type : asList(metadata.getDomainType(), Object.class)) {
-
-			Method saveMethodCandidate = findMethod(metadata.getRepositoryInterface(), SAVE, type);
-
-			if (saveMethodCandidate != null) {
-				return getMostSpecificMethod(saveMethodCandidate, metadata.getRepositoryInterface());
-			}
-		}
+	private static Optional<Method> selectMostSuitableSaveMethod(RepositoryMetadata metadata) {
 
-		return Optional.empty();
+		return asList(metadata.getDomainType(), Object.class).stream()//
+				.flatMap(it -> toStream(findMethod(metadata.getRepositoryInterface(), SAVE, it)))//
+				.flatMap(it -> toStream(getMostSpecificMethod(it, metadata.getRepositoryInterface())))//
+				.findFirst();
 	}
 
 	/**
@@ -98,25 +96,28 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * <ol>
 	 * <li>a {@link RepositoryMetadata#getDomainType()} as first parameter over</li>
 	 * <li>a {@link RepositoryMetadata#getIdType()} as first parameter over</li>
-	 * <li>a {@link Serializable} as first parameter over</li>
+	 * <li>a {@link Object} as first parameter over</li>
 	 * <li>an {@link Iterable} as first parameter.</li>
 	 * </ol>
 	 * 
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	private Optional<Method> selectMostSuitableDeleteMethod(RepositoryMetadata metadata) {
+	private static Optional<Method> selectMostSuitableDeleteMethod(RepositoryMetadata metadata) {
 
-		for (Class<?> type : asList(metadata.getDomainType(), metadata.getIdType(), Serializable.class, Iterable.class)) {
+		Stream<Pair<String, Class<?>>> source = Stream.of(//
+				Pair.of(DELETE, metadata.getDomainType()), //
+				Pair.of(DELETE_BY_ID, metadata.getIdType()), //
+				Pair.of(DELETE, Object.class), //
+				Pair.of(DELETE_BY_ID, Object.class), //
+				Pair.of(DELETE, Iterable.class));
 
-			Method candidate = findMethod(metadata.getRepositoryInterface(), DELETE, type);
+		Class<?> repositoryInterface = metadata.getRepositoryInterface();
 
-			if (candidate != null) {
-				return getMostSpecificMethod(candidate, metadata.getRepositoryInterface());
-			}
-		}
-
-		return Optional.empty();
+		return source//
+				.flatMap(it -> toStream(findMethod(repositoryInterface, it.getFirst(), it.getSecond())))//
+				.flatMap(it -> toStream(getMostSpecificMethod(it, repositoryInterface)))//
+				.findFirst();
 	}
 
 	/**
@@ -130,49 +131,37 @@ public class DefaultCrudMethods implements CrudMethods {
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	private Optional<Method> selectMostSuitableFindAllMethod(RepositoryMetadata metadata) {
-
-		for (Class<?> type : asList(Pageable.class, Sort.class)) {
-
-			if (hasMethod(metadata.getRepositoryInterface(), FIND_ALL, type)) {
+	private static Optional<Method> selectMostSuitableFindAllMethod(RepositoryMetadata metadata) {
 
-				Method candidate = findMethod(PagingAndSortingRepository.class, FIND_ALL, type);
+		Class<?> repositoryInterface = metadata.getRepositoryInterface();
 
-				if (candidate != null) {
-					return getMostSpecificMethod(candidate, metadata.getRepositoryInterface());
-				}
-			}
-		}
+		Supplier<Optional<Method>> withPageableOrSort = () -> Stream.of(Pageable.class, Sort.class)//
+				.flatMap(it -> toStream(findMethod(repositoryInterface, FIND_ALL, it)))//
+				.flatMap(it -> toStream(getMostSpecificMethod(it, repositoryInterface)))//
+				.findFirst();
 
-		if (hasMethod(metadata.getRepositoryInterface(), FIND_ALL)) {
-			return getMostSpecificMethod(findMethod(CrudRepository.class, FIND_ALL), metadata.getRepositoryInterface());
-		}
+		Supplier<Optional<Method>> withoutParameter = () -> findMethod(repositoryInterface, FIND_ALL)//
+				.flatMap(it -> getMostSpecificMethod(it, repositoryInterface));
 
-		return Optional.empty();
+		return firstNonEmpty(withPageableOrSort, withoutParameter);
 	}
 
 	/**
-	 * The most suitable findOne method is selected as follows: We prefer
+	 * The most suitable {@code findById} method is selected as follows: We prefer
 	 * <ol>
 	 * <li>a {@link RepositoryMetadata#getIdType()} as first parameter over</li>
-	 * <li>a {@link Serializable} as first parameter</li>
+	 * <li>a {@link Object} as first parameter</li>
 	 * </ol>
 	 * 
 	 * @param metadata must not be {@literal null}.
 	 * @return the most suitable method or {@literal null} if no method could be found.
 	 */
-	private Optional<Method> selectMostSuitableFindOneMethod(RepositoryMetadata metadata) {
-
-		for (Class<?> type : asList(metadata.getIdType(), Serializable.class)) {
-
-			Method candidate = findMethod(metadata.getRepositoryInterface(), FIND_ONE, type);
+	private static Optional<Method> selectMostSuitableFindOneMethod(RepositoryMetadata metadata) {
 
-			if (candidate != null) {
-				return getMostSpecificMethod(candidate, metadata.getRepositoryInterface());
-			}
-		}
-
-		return Optional.empty();
+		return asList(metadata.getIdType(), Object.class).stream()//
+				.flatMap(it -> toStream(findMethod(metadata.getRepositoryInterface(), FIND_ONE, it)))//
+				.flatMap(it -> toStream(getMostSpecificMethod(it, metadata.getRepositoryInterface())))//
+				.findFirst();
 	}
 
 	/**
@@ -186,10 +175,10 @@ public class DefaultCrudMethods implements CrudMethods {
 	 */
 	private static Optional<Method> getMostSpecificMethod(Method method, Class<?> type) {
 
-		return Optional.ofNullable(ClassUtils.getMostSpecificMethod(method, type)).map(it -> {
-			ReflectionUtils.makeAccessible(it);
-			return it;
-		});
+		return Optionals.toStream(Optional.ofNullable(ClassUtils.getMostSpecificMethod(method, type)))//
+				.map(it -> BridgeMethodResolver.findBridgedMethod(it))//
+				.peek(it -> ReflectionUtils.makeAccessible(it))//
+				.findFirst();
 	}
 
 	/* 
@@ -263,4 +252,8 @@ public class DefaultCrudMethods implements CrudMethods {
 	public Optional<Method> getDeleteMethod() {
 		return this.deleteMethod;
 	}
+
+	private static Optional<Method> findMethod(Class<?> type, String name, Class<?>... parameterTypes) {
+		return Optional.ofNullable(ReflectionUtils.findMethod(type, name, parameterTypes));
+	}
 }

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

@@ -19,7 +19,6 @@ import static org.springframework.core.GenericTypeResolver.*;
 import static org.springframework.data.repository.util.ClassUtils.*;
 import static org.springframework.util.ReflectionUtils.*;
 
-import java.io.Serializable;
 import java.lang.reflect.GenericDeclaration;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -101,7 +100,7 @@ class DefaultRepositoryInformation implements RepositoryInformation {
 	 * @see org.springframework.data.repository.support.RepositoryMetadata#getIdClass()
 	 */
 	@Override
-	public Class<? extends Serializable> getIdType() {
+	public Class<?> getIdType() {
 		return metadata.getIdType();
 	}
 

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

@@ -17,7 +17,6 @@ package org.springframework.data.repository.core.support;
 
 import lombok.Getter;
 
-import java.io.Serializable;
 import java.util.List;
 
 import org.springframework.data.repository.Repository;
@@ -39,7 +38,7 @@ public class DefaultRepositoryMetadata extends AbstractRepositoryMetadata {
 	private static final String MUST_BE_A_REPOSITORY = String.format("Given type must be assignable to %s!",
 			Repository.class);
 
-	private final Class<? extends Serializable> idType;
+	private final Class<?> idType;
 	private final Class<?> domainType;
 
 	/**
@@ -56,8 +55,7 @@ public class DefaultRepositoryMetadata extends AbstractRepositoryMetadata {
 		this.domainType = resolveDomainType(repositoryInterface);
 	}
 
-	@SuppressWarnings("unchecked")
-	private Class<? extends Serializable> resolveIdType(Class<?> repositoryInterface) {
+	private static Class<?> resolveIdType(Class<?> repositoryInterface) {
 
 		TypeInformation<?> information = ClassTypeInformation.from(repositoryInterface);
 		List<TypeInformation<?>> arguments = information.getSuperTypeInformation(Repository.class).getTypeArguments();
@@ -66,10 +64,10 @@ public class DefaultRepositoryMetadata extends AbstractRepositoryMetadata {
 			throw new IllegalArgumentException(String.format("Could not resolve id type of %s!", repositoryInterface));
 		}
 
-		return (Class<? extends Serializable>) arguments.get(1).getType();
+		return arguments.get(1).getType();
 	}
 
-	private Class<?> resolveDomainType(Class<?> repositoryInterface) {
+	private static Class<?> resolveDomainType(Class<?> repositoryInterface) {
 
 		TypeInformation<?> information = ClassTypeInformation.from(repositoryInterface);
 		List<TypeInformation<?>> arguments = information.getSuperTypeInformation(Repository.class).getTypeArguments();

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

@@ -15,11 +15,12 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+
 import java.util.Optional;
 
 import org.springframework.data.repository.core.EntityInformation;
-import org.springframework.util.Assert;
 
 /**
  * Useful base class to implement custom {@link EntityInformation}s and delegate execution of standard methods from
@@ -27,21 +28,10 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public class DelegatingEntityInformation<T, ID extends Serializable> implements EntityInformation<T, ID> {
-
-	private final EntityInformation<T, ID> delegate;
+@RequiredArgsConstructor
+public class DelegatingEntityInformation<T, ID> implements EntityInformation<T, ID> {
 
-	/**
-	 * Creates a new {@link DelegatingEntityInformation} delegating method invocations to the given
-	 * {@link EntityInformation}.
-	 * 
-	 * @param delegate
-	 */
-	public DelegatingEntityInformation(EntityInformation<T, ID> delegate) {
-
-		Assert.notNull(delegate, "Delegate EnittyInformation must not be null!");
-		this.delegate = delegate;
-	}
+	private final @NonNull EntityInformation<T, ID> delegate;
 
 	/* 
 	 * (non-Javadoc)

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

@@ -18,10 +18,10 @@ package org.springframework.data.repository.core.support;
 import lombok.RequiredArgsConstructor;
 
 import java.lang.reflect.Method;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
+import java.util.stream.Stream;
 
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
@@ -90,7 +90,7 @@ public class EventPublishingRepositoryProxyPostProcessor implements RepositoryPr
 
 			Object result = invocation.proceed();
 
-			if (!invocation.getMethod().getName().equals("save")) {
+			if (!Stream.of("save", "saveAll").anyMatch(it -> invocation.getMethod().getName().equals(it))) {
 				return result;
 			}
 

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

@@ -15,10 +15,9 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
 import java.util.Optional;
 
-import org.springframework.core.GenericTypeResolver;
+import org.springframework.core.ResolvableType;
 import org.springframework.data.domain.Persistable;
 import org.springframework.data.repository.core.EntityMetadata;
 
@@ -28,8 +27,7 @@ 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 AbstractEntityInformation<T, ID> {
 
 	private Class<ID> idClass;
 
@@ -42,7 +40,7 @@ public class PersistableEntityInformation<T extends Persistable<ID>, ID extends
 	public PersistableEntityInformation(Class<T> domainClass) {
 
 		super(domainClass);
-		this.idClass = (Class<ID>) GenericTypeResolver.resolveTypeArgument(domainClass, Persistable.class);
+		this.idClass = (Class<ID>) ResolvableType.forClass(Persistable.class, domainClass).resolveGeneric(0);
 	}
 
 	/*

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
 import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
@@ -30,7 +29,7 @@ import org.springframework.data.repository.core.EntityInformation;
  * @author Christoph Strobl
  */
 @SuppressWarnings("unchecked")
-public class PersistentEntityInformation<T, ID extends Serializable> extends AbstractEntityInformation<T, ID> {
+public class PersistentEntityInformation<T, ID> extends AbstractEntityInformation<T, ID> {
 
 	private final PersistentEntity<T, ? extends PersistentProperty<?>> persistentEntity;
 

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

@@ -15,7 +15,6 @@
  */
 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;
@@ -32,7 +31,7 @@ import org.springframework.util.ReflectionUtils;
  * @author Oliver Gierke
  * @author Christoph Strobl
  */
-public class ReflectionEntityInformation<T, ID extends Serializable> extends AbstractEntityInformation<T, ID> {
+public class ReflectionEntityInformation<T, ID> extends AbstractEntityInformation<T, ID> {
 
 	private static final Class<Id> DEFAULT_ID_ANNOTATION = Id.class;
 

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
 import java.util.List;
 import java.util.Optional;
 
@@ -50,7 +49,7 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @author Thomas Darimont
  */
-public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>, S, ID extends Serializable>
+public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>, S, ID>
 		implements InitializingBean, RepositoryFactoryInformation<S, ID>, FactoryBean<T>, BeanClassLoaderAware,
 		BeanFactoryAware, ApplicationEventPublisherAware {
 

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
 import java.util.List;
 
 import org.springframework.data.mapping.PersistentEntity;
@@ -31,7 +30,7 @@ import org.springframework.data.repository.query.QueryMethod;
  * 
  * @author Oliver Gierke
  */
-public interface RepositoryFactoryInformation<T, ID extends Serializable> {
+public interface RepositoryFactoryInformation<T, ID> {
 
 	/**
 	 * Returns {@link EntityInformation} the repository factory is using.

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

@@ -19,7 +19,6 @@ import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
-import java.io.Serializable;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
@@ -291,7 +290,7 @@ public abstract class RepositoryFactorySupport implements BeanClassLoaderAware,
 	 * @param domainClass
 	 * @return
 	 */
-	public abstract <T, ID extends Serializable> EntityInformation<T, ID> getEntityInformation(Class<T> domainClass);
+	public abstract <T, ID> EntityInformation<T, ID> getEntityInformation(Class<T> domainClass);
 
 	/**
 	 * Create a repository instance as backing for the query proxy.

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

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
-
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.ListableBeanFactory;
@@ -32,7 +30,7 @@ import org.springframework.util.Assert;
  * 
  * @author Oliver Gierke
  */
-public abstract class TransactionalRepositoryFactoryBeanSupport<T extends Repository<S, ID>, S, ID extends Serializable>
+public abstract class TransactionalRepositoryFactoryBeanSupport<T extends Repository<S, ID>, S, ID>
 		extends RepositoryFactoryBeanSupport<T, S, ID> implements BeanFactoryAware {
 
 	private String transactionManagerName = TxUtils.DEFAULT_TRANSACTION_MANAGER;

src/main/java/org/springframework/data/repository/history/RevisionRepository.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.history;
 
-import java.io.Serializable;
 import java.util.Optional;
 
 import org.springframework.data.domain.Page;
@@ -33,8 +32,7 @@ import org.springframework.data.repository.Repository;
  * @author Philipp Huegelmeyer
  */
 @NoRepositoryBean
-public interface RevisionRepository<T, ID extends Serializable, N extends Number & Comparable<N>>
-		extends Repository<T, ID> {
+public interface RevisionRepository<T, ID, N extends Number & Comparable<N>> extends Repository<T, ID> {
 
 	/**
 	 * Returns the revision of the entity it was last changed in.

src/main/java/org/springframework/data/repository/reactive/ReactiveCrudRepository.java

@@ -15,15 +15,13 @@
  */
 package org.springframework.data.repository.reactive;
 
-import java.io.Serializable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import org.reactivestreams.Publisher;
 import org.springframework.data.repository.NoRepositoryBean;
 import org.springframework.data.repository.Repository;
 
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
 /**
  * Interface for generic CRUD operations on a repository for a specific type. This repository follows reactive paradigms
  * and uses Project Reactor types which are built on top of Reactive Streams.
@@ -34,7 +32,7 @@ import reactor.core.publisher.Mono;
  * @see Flux
  */
 @NoRepositoryBean
-public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repository<T, ID> {
+public interface ReactiveCrudRepository<T, ID> extends Repository<T, ID> {
 
 	/**
 	 * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
@@ -52,7 +50,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given entity is {@literal null}.
 	 */
-	<S extends T> Flux<S> save(Iterable<S> entities);
+	<S extends T> Flux<S> saveAll(Iterable<S> entities);
 
 	/**
 	 * Saves all given entities.
@@ -61,7 +59,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given {@code Publisher} is {@literal null}.
 	 */
-	<S extends T> Flux<S> save(Publisher<S> entityStream);
+	<S extends T> Flux<S> saveAll(Publisher<S> entityStream);
 
 	/**
 	 * Retrieves an entity by its id.
@@ -70,7 +68,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return the entity with the given id or {@link Mono#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Mono<T> findOne(ID id);
+	Mono<T> findById(ID id);
 
 	/**
 	 * Retrieves an entity by its id supplied by a {@link Mono}.
@@ -79,7 +77,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return the entity with the given id or {@link Mono#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Mono<T> findOne(Mono<ID> id);
+	Mono<T> findById(Mono<ID> id);
 
 	/**
 	 * Returns whether an entity with the given id exists.
@@ -88,7 +86,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Mono<Boolean> exists(ID id);
+	Mono<Boolean> existsById(ID id);
 
 	/**
 	 * Returns whether an entity with the given id, supplied by a {@link Mono}, exists.
@@ -97,7 +95,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}
 	 */
-	Mono<Boolean> exists(Mono<ID> id);
+	Mono<Boolean> existsById(Mono<ID> id);
 
 	/**
 	 * Returns all instances of the type.
@@ -112,7 +110,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @param ids must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Flux<T> findAll(Iterable<ID> ids);
+	Flux<T> findAllById(Iterable<ID> ids);
 
 	/**
 	 * Returns all instances of the type with the given IDs.
@@ -120,7 +118,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @param idStream must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Flux<T> findAll(Publisher<ID> idStream);
+	Flux<T> findAllById(Publisher<ID> idStream);
 
 	/**
 	 * Returns the number of entities available.
@@ -135,7 +133,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @param id must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@code id} is {@literal null}.
 	 */
-	Mono<Void> delete(ID id);
+	Mono<Void> deleteById(ID id);
 
 	/**
 	 * Deletes a given entity.
@@ -151,7 +149,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @param entities must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
 	 */
-	Mono<Void> delete(Iterable<? extends T> entities);
+	Mono<Void> deleteAll(Iterable<? extends T> entities);
 
 	/**
 	 * Deletes the given entities.
@@ -159,7 +157,7 @@ public interface ReactiveCrudRepository<T, ID extends Serializable> extends Repo
 	 * @param entityStream must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Publisher} is {@literal null}.
 	 */
-	Mono<Void> delete(Publisher<? extends T> entityStream);
+	Mono<Void> deleteAll(Publisher<? extends T> entityStream);
 
 	/**
 	 * Deletes all entities managed by the repository.

src/main/java/org/springframework/data/repository/reactive/ReactiveSortingRepository.java

@@ -15,14 +15,12 @@
  */
 package org.springframework.data.repository.reactive;
 
-import java.io.Serializable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.NoRepositoryBean;
 
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-
 /**
  * Extension of {@link ReactiveCrudRepository} to provide additional methods to retrieve entities using the sorting
  * abstraction.
@@ -34,7 +32,7 @@ import reactor.core.publisher.Mono;
  * @see Flux
  */
 @NoRepositoryBean
-public interface ReactiveSortingRepository<T, ID extends Serializable> extends ReactiveCrudRepository<T, ID> {
+public interface ReactiveSortingRepository<T, ID> extends ReactiveCrudRepository<T, ID> {
 
 	/**
 	 * Returns all entities sorted by the given options.

src/main/java/org/springframework/data/repository/reactive/RxJava1CrudRepository.java

@@ -15,15 +15,13 @@
  */
 package org.springframework.data.repository.reactive;
 
-import java.io.Serializable;
-
-import org.springframework.data.repository.NoRepositoryBean;
-import org.springframework.data.repository.Repository;
-
 import rx.Completable;
 import rx.Observable;
 import rx.Single;
 
+import org.springframework.data.repository.NoRepositoryBean;
+import org.springframework.data.repository.Repository;
+
 /**
  * Interface for generic CRUD operations on a repository for a specific type. This repository follows reactive paradigms
  * and uses RxJava 1 types.
@@ -34,7 +32,7 @@ import rx.Single;
  * @see Observable
  */
 @NoRepositoryBean
-public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repository<T, ID> {
+public interface RxJava1CrudRepository<T, ID> extends Repository<T, ID> {
 
 	/**
 	 * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
@@ -52,7 +50,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given entity is {@literal null}.
 	 */
-	<S extends T> Observable<S> save(Iterable<S> entities);
+	<S extends T> Observable<S> saveAll(Iterable<S> entities);
 
 	/**
 	 * Saves all given entities.
@@ -61,7 +59,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given {@code Publisher} is {@literal null}.
 	 */
-	<S extends T> Observable<S> save(Observable<S> entityStream);
+	<S extends T> Observable<S> saveAll(Observable<S> entityStream);
 
 	/**
 	 * Retrieves an entity by its id.
@@ -70,7 +68,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the entity with the given id or {@link Observable#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Observable<T> findOne(ID id);
+	Observable<T> findById(ID id);
 
 	/**
 	 * Retrieves an entity by its id supplied by a {@link Single}.
@@ -79,7 +77,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the entity with the given id or {@link Observable#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Observable<T> findOne(Single<ID> id);
+	Observable<T> findById(Single<ID> id);
 
 	/**
 	 * Returns whether an entity with the given id exists.
@@ -88,7 +86,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Single<Boolean> exists(ID id);
+	Single<Boolean> existsById(ID id);
 
 	/**
 	 * Returns whether an entity with the given id, supplied by a {@link Single}, exists.
@@ -97,7 +95,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Single<Boolean> exists(Single<ID> id);
+	Single<Boolean> existsById(Single<ID> id);
 
 	/**
 	 * Returns all instances of the type.
@@ -112,7 +110,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param ids must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Observable<T> findAll(Iterable<ID> ids);
+	Observable<T> findAllById(Iterable<ID> ids);
 
 	/**
 	 * Returns all instances of the type with the given IDs.
@@ -120,7 +118,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param idStream must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Observable<T> findAll(Observable<ID> idStream);
+	Observable<T> findAllById(Observable<ID> idStream);
 
 	/**
 	 * Returns the number of entities available.
@@ -135,7 +133,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param id must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@code id} is {@literal null}.
 	 */
-	Completable delete(ID id);
+	Completable deleteById(ID id);
 
 	/**
 	 * Deletes a given entity.
@@ -151,7 +149,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param entities must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
 	 */
-	Completable delete(Iterable<? extends T> entities);
+	Completable deleteAll(Iterable<? extends T> entities);
 
 	/**
 	 * Deletes the given entities.
@@ -159,7 +157,7 @@ public interface RxJava1CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param entityStream must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Observable} is {@literal null}.
 	 */
-	Completable delete(Observable<? extends T> entityStream);
+	Completable deleteAll(Observable<? extends T> entityStream);
 
 	/**
 	 * Deletes all entities managed by the repository.

src/main/java/org/springframework/data/repository/reactive/RxJava1SortingRepository.java

@@ -15,14 +15,12 @@
  */
 package org.springframework.data.repository.reactive;
 
-import java.io.Serializable;
+import rx.Observable;
+import rx.Single;
 
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.NoRepositoryBean;
 
-import rx.Observable;
-import rx.Single;
-
 /**
  * Extension of {@link RxJava1CrudRepository} to provide additional methods to retrieve entities using the sorting
  * abstraction.
@@ -35,7 +33,7 @@ import rx.Single;
  * @see RxJava1CrudRepository
  */
 @NoRepositoryBean
-public interface RxJava1SortingRepository<T, ID extends Serializable> extends RxJava1CrudRepository<T, ID> {
+public interface RxJava1SortingRepository<T, ID> extends RxJava1CrudRepository<T, ID> {
 
 	/**
 	 * Returns all entities sorted by the given options.

src/main/java/org/springframework/data/repository/reactive/RxJava2CrudRepository.java

@@ -20,8 +20,6 @@ import io.reactivex.Flowable;
 import io.reactivex.Maybe;
 import io.reactivex.Single;
 
-import java.io.Serializable;
-
 import org.springframework.data.repository.NoRepositoryBean;
 import org.springframework.data.repository.Repository;
 
@@ -37,7 +35,7 @@ import org.springframework.data.repository.Repository;
  * @see Completable
  */
 @NoRepositoryBean
-public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repository<T, ID> {
+public interface RxJava2CrudRepository<T, ID> extends Repository<T, ID> {
 
 	/**
 	 * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
@@ -55,7 +53,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given entity is {@literal null}.
 	 */
-	<S extends T> Flowable<S> save(Iterable<S> entities);
+	<S extends T> Flowable<S> saveAll(Iterable<S> entities);
 
 	/**
 	 * Saves all given entities.
@@ -64,7 +62,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the saved entities.
 	 * @throws IllegalArgumentException in case the given {@code Publisher} is {@literal null}.
 	 */
-	<S extends T> Flowable<S> save(Flowable<S> entityStream);
+	<S extends T> Flowable<S> saveAll(Flowable<S> entityStream);
 
 	/**
 	 * Retrieves an entity by its id.
@@ -73,7 +71,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the entity with the given id or {@link Maybe#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Maybe<T> findOne(ID id);
+	Maybe<T> findById(ID id);
 
 	/**
 	 * Retrieves an entity by its id supplied by a {@link Single}.
@@ -82,7 +80,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return the entity with the given id or {@link Maybe#empty()} if none found.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Maybe<T> findOne(Single<ID> id);
+	Maybe<T> findById(Single<ID> id);
 
 	/**
 	 * Returns whether an entity with the given id exists.
@@ -91,7 +89,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}.
 	 */
-	Single<Boolean> exists(ID id);
+	Single<Boolean> existsById(ID id);
 
 	/**
 	 * Returns whether an entity with the given id, supplied by a {@link Single}, exists.
@@ -100,7 +98,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
 	 * @throws IllegalArgumentException if {@code id} is {@literal null}
 	 */
-	Single<Boolean> exists(Single<ID> id);
+	Single<Boolean> existsById(Single<ID> id);
 
 	/**
 	 * Returns all instances of the type.
@@ -115,7 +113,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param ids must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Flowable<T> findAll(Iterable<ID> ids);
+	Flowable<T> findAllById(Iterable<ID> ids);
 
 	/**
 	 * Returns all instances of the type with the given IDs.
@@ -123,7 +121,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param idStream must not be {@literal null}.
 	 * @return the found entities.
 	 */
-	Flowable<T> findAll(Flowable<ID> idStream);
+	Flowable<T> findAllById(Flowable<ID> idStream);
 
 	/**
 	 * Returns the number of entities available.
@@ -138,7 +136,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param id must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@code id} is {@literal null}.
 	 */
-	Completable delete(ID id);
+	Completable deleteById(ID id);
 
 	/**
 	 * Deletes a given entity.
@@ -154,7 +152,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param entities must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
 	 */
-	Completable delete(Iterable<? extends T> entities);
+	Completable deleteAll(Iterable<? extends T> entities);
 
 	/**
 	 * Deletes the given entities.
@@ -162,7 +160,7 @@ public interface RxJava2CrudRepository<T, ID extends Serializable> extends Repos
 	 * @param entityStream must not be {@literal null}.
 	 * @throws IllegalArgumentException in case the given {@link Flowable} is {@literal null}.
 	 */
-	Completable delete(Flowable<? extends T> entityStream);
+	Completable deleteAll(Flowable<? extends T> entityStream);
 
 	/**
 	 * Deletes all entities managed by the repository.

src/main/java/org/springframework/data/repository/reactive/RxJava2SortingRepository.java

@@ -17,8 +17,6 @@ package org.springframework.data.repository.reactive;
 
 import io.reactivex.Flowable;
 
-import java.io.Serializable;
-
 import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.NoRepositoryBean;
 
@@ -33,7 +31,7 @@ import org.springframework.data.repository.NoRepositoryBean;
  * @see RxJava2CrudRepository
  */
 @NoRepositoryBean
-public interface RxJava2SortingRepository<T, ID extends Serializable> extends RxJava2CrudRepository<T, ID> {
+public interface RxJava2SortingRepository<T, ID> extends RxJava2CrudRepository<T, ID> {
 
 	/**
 	 * Returns all entities sorted by the given options.

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.support;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -36,7 +35,7 @@ import org.springframework.data.repository.core.RepositoryMetadata;
  */
 class CrudRepositoryInvoker extends ReflectionRepositoryInvoker {
 
-	private final CrudRepository<Object, Serializable> repository;
+	private final CrudRepository<Object, Object> repository;
 
 	private final boolean customSaveMethod;
 	private final boolean customFindOneMethod;
@@ -51,7 +50,7 @@ class CrudRepositoryInvoker extends ReflectionRepositoryInvoker {
 	 * @param metadata must not be {@literal null}.
 	 * @param conversionService must not be {@literal null}.
 	 */
-	public CrudRepositoryInvoker(CrudRepository<Object, Serializable> repository, RepositoryMetadata metadata,
+	public CrudRepositoryInvoker(CrudRepository<Object, Object> repository, RepositoryMetadata metadata,
 			ConversionService conversionService) {
 
 		super(repository, metadata, conversionService);
@@ -85,12 +84,12 @@ class CrudRepositoryInvoker extends ReflectionRepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.rest.core.invoke.RepositoryInvoker#invokeFindOne(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.ReflectionRepositoryInvoker#invokeFindById(java.lang.Object)
 	 */
 	@Override
 	@SuppressWarnings("unchecked")
-	public <T> Optional<T> invokeFindOne(Serializable id) {
-		return customFindOneMethod ? super.invokeFindOne(id) : (Optional<T>) repository.findOne(convertId(id));
+	public <T> Optional<T> invokeFindById(Object id) {
+		return customFindOneMethod ? super.invokeFindById(id) : (Optional<T>) repository.findById(convertId(id));
 	}
 
 	/*
@@ -104,15 +103,15 @@ class CrudRepositoryInvoker extends ReflectionRepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.rest.core.invoke.RepositoryInvoker#invokeDelete(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.ReflectionRepositoryInvoker#invokeDeleteById(java.lang.Object)
 	 */
 	@Override
-	public void invokeDelete(Serializable id) {
+	public void invokeDeleteById(Object id) {
 
 		if (customDeleteMethod) {
-			super.invokeDelete(id);
+			super.invokeDeleteById(id);
 		} else {
-			repository.delete(convertId(id));
+			repository.deleteById(convertId(id));
 		}
 	}
 

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

@@ -17,7 +17,6 @@ package org.springframework.data.repository.support;
 
 import static org.springframework.data.util.Optionals.*;
 
-import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
@@ -100,11 +99,10 @@ public class DefaultRepositoryInvokerFactory implements RepositoryInvokerFactory
 	protected RepositoryInvoker createInvoker(RepositoryInformation information, Object repository) {
 
 		if (repository instanceof PagingAndSortingRepository) {
-			return new PagingAndSortingRepositoryInvoker((PagingAndSortingRepository<Object, Serializable>) repository,
-					information, conversionService);
-		} else if (repository instanceof CrudRepository) {
-			return new CrudRepositoryInvoker((CrudRepository<Object, Serializable>) repository, information,
+			return new PagingAndSortingRepositoryInvoker((PagingAndSortingRepository<Object, Object>) repository, information,
 					conversionService);
+		} else if (repository instanceof CrudRepository) {
+			return new CrudRepositoryInvoker((CrudRepository<Object, Object>) repository, information, conversionService);
 		} else {
 			return new ReflectionRepositoryInvoker(repository, information, conversionService);
 		}

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

@@ -154,7 +154,7 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 			RepositoryInvoker invoker = repositoryInvokerFactory.getInvokerFor(domainType);
 			RepositoryInformation information = repositories.getRequiredRepositoryInformation(domainType);
 
-			return invoker.invokeFindOne(conversionService.convert(source, information.getIdType())).orElse(null);
+			return invoker.invokeFindById(conversionService.convert(source, information.getIdType())).orElse(null);
 		}
 
 		/*

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.support;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -35,7 +34,7 @@ import org.springframework.data.repository.core.RepositoryMetadata;
  */
 class PagingAndSortingRepositoryInvoker extends CrudRepositoryInvoker {
 
-	private final PagingAndSortingRepository<Object, Serializable> repository;
+	private final PagingAndSortingRepository<Object, Object> repository;
 	private final boolean customFindAll;
 
 	/**
@@ -46,7 +45,7 @@ class PagingAndSortingRepositoryInvoker extends CrudRepositoryInvoker {
 	 * @param metadata must not be {@literal null}.
 	 * @param conversionService must not be {@literal null}.
 	 */
-	public PagingAndSortingRepositoryInvoker(PagingAndSortingRepository<Object, Serializable> repository,
+	public PagingAndSortingRepositoryInvoker(PagingAndSortingRepository<Object, Object> repository,
 			RepositoryMetadata metadata, ConversionService conversionService) {
 
 		super(repository, metadata, conversionService);

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.support;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
@@ -50,7 +49,7 @@ class ReflectionRepositoryInvoker implements RepositoryInvoker {
 
 	private final Object repository;
 	private final CrudMethods methods;
-	private final Class<? extends Serializable> idType;
+	private final Class<?> idType;
 	private final ConversionService conversionService;
 
 	/**
@@ -133,10 +132,10 @@ class ReflectionRepositoryInvoker implements RepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.rest.core.invoke.RepositoryInvoker#invokeFindOne(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeFindById(java.lang.Object)
 	 */
 	@Override
-	public <T> Optional<T> invokeFindOne(Serializable id) {
+	public <T> Optional<T> invokeFindById(Object id) {
 
 		Method method = methods.getFindOneMethod()//
 				.orElseThrow(() -> new IllegalStateException("Repository doesn't have a find-one-method declared!"));
@@ -155,22 +154,22 @@ class ReflectionRepositoryInvoker implements RepositoryInvoker {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.rest.core.invoke.RepositoryInvoker#invokeDelete(java.io.Serializable)
+	 * @see org.springframework.data.repository.support.RepositoryInvoker#invokeDeleteById(java.lang.Object)
 	 */
 	@Override
-	public void invokeDelete(Serializable id) {
+	public void invokeDeleteById(Object id) {
 
 		Assert.notNull(id, "Identifier must not be null!");
 
 		Method method = methods.getDeleteMethod()
 				.orElseThrow(() -> new IllegalStateException("Repository doesn't have a delete-method declared!"));
 		Class<?> parameterType = method.getParameterTypes()[0];
-		List<Class<? extends Serializable>> idTypes = Arrays.asList(idType, Serializable.class);
+		List<Class<?>> idTypes = Arrays.asList(idType, Object.class);
 
 		if (idTypes.contains(parameterType)) {
 			invoke(method, convertId(id));
 		} else {
-			invoke(method, this.<Object> invokeFindOne(id).orElse(null));
+			invoke(method, this.<Object> invokeFindById(id).orElse(null));
 		}
 	}
 
@@ -263,7 +262,7 @@ class ReflectionRepositoryInvoker implements RepositoryInvoker {
 	 * @param id must not be {@literal null}.
 	 * @return
 	 */
-	protected Serializable convertId(Serializable id) {
+	protected Object convertId(Object id) {
 
 		Assert.notNull(id, "Id must not be null!");
 		return conversionService.convert(id, idType);

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.support;
 
-import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -49,12 +48,12 @@ public class Repositories implements Iterable<Class<?>> {
 
 	static final Repositories NONE = new Repositories();
 
-	private static final RepositoryFactoryInformation<Object, Serializable> EMPTY_REPOSITORY_FACTORY_INFO = EmptyRepositoryFactoryInformation.INSTANCE;
+	private static final RepositoryFactoryInformation<Object, Object> EMPTY_REPOSITORY_FACTORY_INFO = EmptyRepositoryFactoryInformation.INSTANCE;
 	private static final String DOMAIN_TYPE_MUST_NOT_BE_NULL = "Domain type must not be null!";
 
 	private final Optional<BeanFactory> beanFactory;
 	private final Map<Class<?>, String> repositoryBeanNames;
-	private final Map<Class<?>, RepositoryFactoryInformation<Object, Serializable>> repositoryFactoryInfos;
+	private final Map<Class<?>, RepositoryFactoryInformation<Object, Object>> repositoryFactoryInfos;
 
 	/**
 	 * Constructor to create the {@link #NONE} instance.
@@ -148,12 +147,12 @@ public class Repositories implements Iterable<Class<?>> {
 	 * @return the {@link RepositoryFactoryInformation} for the given domain class or {@literal null} if no repository
 	 *         registered for this domain class.
 	 */
-	private RepositoryFactoryInformation<Object, Serializable> getRepositoryFactoryInfoFor(Class<?> domainClass) {
+	private RepositoryFactoryInformation<Object, Object> getRepositoryFactoryInfoFor(Class<?> domainClass) {
 
 		Assert.notNull(domainClass, DOMAIN_TYPE_MUST_NOT_BE_NULL);
 
 		Class<?> userType = ClassUtils.getUserClass(domainClass);
-		RepositoryFactoryInformation<Object, Serializable> repositoryInfo = repositoryFactoryInfos.get(userType);
+		RepositoryFactoryInformation<Object, Object> repositoryInfo = repositoryFactoryInfos.get(userType);
 
 		if (repositoryInfo != null) {
 			return repositoryInfo;
@@ -173,7 +172,7 @@ public class Repositories implements Iterable<Class<?>> {
 	 * @return
 	 */
 	@SuppressWarnings("unchecked")
-	public <T, S extends Serializable> EntityInformation<T, S> getEntityInformationFor(Class<?> domainClass) {
+	public <T, S> EntityInformation<T, S> getEntityInformationFor(Class<?> domainClass) {
 
 		Assert.notNull(domainClass, DOMAIN_TYPE_MUST_NOT_BE_NULL);
 
@@ -191,7 +190,7 @@ public class Repositories implements Iterable<Class<?>> {
 
 		Assert.notNull(domainClass, DOMAIN_TYPE_MUST_NOT_BE_NULL);
 
-		RepositoryFactoryInformation<Object, Serializable> information = getRepositoryFactoryInfoFor(domainClass);
+		RepositoryFactoryInformation<Object, Object> information = getRepositoryFactoryInfoFor(domainClass);
 		return information == EMPTY_REPOSITORY_FACTORY_INFO ? Optional.empty()
 				: Optional.of(information.getRepositoryInformation());
 	}
@@ -264,12 +263,12 @@ public class Repositories implements Iterable<Class<?>> {
 	 * 
 	 * @author Thomas Darimont
 	 */
-	private static enum EmptyRepositoryFactoryInformation implements RepositoryFactoryInformation<Object, Serializable> {
+	private static enum EmptyRepositoryFactoryInformation implements RepositoryFactoryInformation<Object, Object> {
 
 		INSTANCE;
 
 		@Override
-		public EntityInformation<Object, Serializable> getEntityInformation() {
+		public EntityInformation<Object, Object> getEntityInformation() {
 			return null;
 		}
 

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.support;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -44,13 +43,13 @@ public interface RepositoryInvoker extends RepositoryInvocationInformation {
 	<T> T invokeSave(T object);
 
 	/**
-	 * Invokes the method equivalent to {@link org.springframework.data.repository.CrudRepository#findOne(Serializable)}.
+	 * Invokes the method equivalent to {@link org.springframework.data.repository.CrudRepository#findById(Object)}.
 	 * 
 	 * @param id must not be {@literal null}.
 	 * @return the entity with the given id.
 	 * @throws IllegalStateException if the repository does not expose a find-one-method.
 	 */
-	<T> Optional<T> invokeFindOne(Serializable id);
+	<T> Optional<T> invokeFindById(Object id);
 
 	/**
 	 * Invokes the find-all method of the underlying repository using the method taking a {@link Pageable} as parameter if
@@ -80,13 +79,13 @@ public interface RepositoryInvoker extends RepositoryInvocationInformation {
 	Iterable<Object> invokeFindAll(Sort sort);
 
 	/**
-	 * Invokes the method equivalent to {@link org.springframework.data.repository.CrudRepository#delete(Serializable)}.
-	 * The given id is assumed to be of a type convertable into the actual identifier type of the backing repository.
+	 * Invokes the method equivalent to {@link org.springframework.data.repository.CrudRepository#deleteById(Object)}. The
+	 * given id is assumed to be of a type convertible into the actual identifier type of the backing repository.
 	 * 
 	 * @param id must not be {@literal null}.
 	 * @throws {@link IllegalStateException} if the repository does not expose a delete-method.
 	 */
-	void invokeDelete(Serializable id);
+	void invokeDeleteById(Object id);
 
 	/**
 	 * Invokes the query method backed by the given {@link Method} using the given parameters, {@link Pageable} and

src/test/java/org/springframework/data/querydsl/QuerydslRepositoryInvokerAdapterUnitTests.java

@@ -86,11 +86,11 @@ public class QuerydslRepositoryInvokerAdapterUnitTests {
 		adapter.hasSaveMethod();
 		verify(delegate, times(1)).hasSaveMethod();
 
-		adapter.invokeDelete(any(Serializable.class));
-		verify(delegate, times(1)).invokeDelete(any());
+		adapter.invokeDeleteById(any(Serializable.class));
+		verify(delegate, times(1)).invokeDeleteById(any());
 
-		adapter.invokeFindOne(any(Serializable.class));
-		verify(delegate, times(1)).invokeFindOne(any());
+		adapter.invokeFindById(any(Serializable.class));
+		verify(delegate, times(1)).invokeFindById(any());
 
 		adapter.invokeQueryMethod(any(), any(), any(), any());
 

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

@@ -100,7 +100,7 @@ public class AbstractEntityInformationUnitTests {
 		@Id boolean id;
 	}
 
-	static class CustomEntityInformation<T, ID extends Serializable> extends AbstractEntityInformation<T, ID> {
+	static class CustomEntityInformation<T, ID> extends AbstractEntityInformation<T, ID> {
 
 		private final Class<T> type;
 

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

@@ -23,6 +23,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.junit.Test;
+import org.springframework.core.ResolvableType;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.querydsl.User;
@@ -138,12 +139,14 @@ public class AbstractRepositoryMetadataUnitTests {
 			super(repositoryInterface);
 		}
 
+		@SuppressWarnings("unchecked")
 		public Class<? extends Serializable> getIdType() {
-			return null;
+			return (Class<? extends Serializable>) ResolvableType//
+					.forClass(Repository.class, getRepositoryInterface()).getGeneric(1).resolve();
 		}
 
 		public Class<?> getDomainType() {
-			return null;
+			return ResolvableType.forClass(Repository.class, getRepositoryInterface()).getGeneric(0).resolve();
 		}
 	}
 

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

@@ -47,7 +47,7 @@ public class DefaultCrudMethodsUnitTests {
 		Class<DomainCrudRepository> type = DomainCrudRepository.class;
 
 		assertFindAllMethodOn(type, type.getMethod("findAll"));
-		assertDeleteMethodOn(type, type.getMethod("delete", Serializable.class));
+		assertDeleteMethodOn(type, type.getMethod("delete", Object.class));
 		assertSaveMethodPresent(type, true);
 	}
 
@@ -57,7 +57,7 @@ public class DefaultCrudMethodsUnitTests {
 		Class<DomainPagingAndSortingRepository> type = DomainPagingAndSortingRepository.class;
 
 		assertFindAllMethodOn(type, type.getMethod("findAll", Pageable.class));
-		assertDeleteMethodOn(type, type.getMethod("delete", Serializable.class));
+		assertDeleteMethodOn(type, type.getMethod("delete", Object.class));
 		assertSaveMethodPresent(type, true);
 	}
 
@@ -100,8 +100,8 @@ public class DefaultCrudMethodsUnitTests {
 	public void detectsOverloadedMethodsCorrectly() throws Exception {
 
 		Class<RepositoryWithAllCrudMethodOverloaded> type = RepositoryWithAllCrudMethodOverloaded.class;
-		assertFindOneMethodOn(type, type.getDeclaredMethod("findOne", Long.class));
-		assertDeleteMethodOn(type, type.getDeclaredMethod("delete", Long.class));
+		assertFindOneMethodOn(type, type.getDeclaredMethod("findById", Long.class));
+		assertDeleteMethodOn(type, type.getDeclaredMethod("deleteById", Long.class));
 		assertSaveMethodOn(type, type.getDeclaredMethod("save", Domain.class));
 		assertFindAllMethodOn(type, type.getDeclaredMethod("findAll"));
 	}
@@ -110,8 +110,8 @@ public class DefaultCrudMethodsUnitTests {
 	public void ignoresWrongOverloadedMethods() throws Exception {
 
 		Class<RepositoryWithAllCrudMethodOverloadedWrong> type = RepositoryWithAllCrudMethodOverloadedWrong.class;
-		assertFindOneMethodOn(type, CrudRepository.class.getDeclaredMethod("findOne", Serializable.class));
-		assertDeleteMethodOn(type, CrudRepository.class.getDeclaredMethod("delete", Serializable.class));
+		assertFindOneMethodOn(type, CrudRepository.class.getDeclaredMethod("findById", Object.class));
+		assertDeleteMethodOn(type, CrudRepository.class.getDeclaredMethod("delete", Object.class));
 		assertSaveMethodOn(type, CrudRepository.class.getDeclaredMethod("save", Object.class));
 		assertFindAllMethodOn(type, CrudRepository.class.getDeclaredMethod("findAll"));
 	}
@@ -241,9 +241,9 @@ public class DefaultCrudMethodsUnitTests {
 
 		<S extends Domain> S save(S entity);
 
-		void delete(Long id);
+		void deleteById(Long id);
 
-		Optional<Domain> findOne(Long id);
+		Optional<Domain> findById(Long id);
 	}
 
 	// DATACMNS-393
@@ -251,11 +251,11 @@ public class DefaultCrudMethodsUnitTests {
 
 		List<Domain> findAll(String s);
 
-		Domain save(Serializable entity);
+		Domain save(Long entity);
 
 		void delete(String o);
 
-		Domain findOne(Domain o);
+		Domain findById(Domain o);
 	}
 
 	// DATACMNS-539

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

@@ -19,7 +19,6 @@ import static org.assertj.core.api.Assertions.*;
 
 import lombok.experimental.Delegate;
 
-import java.io.Serializable;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -63,19 +62,19 @@ public class DefaultRepositoryInformationUnitTests {
 	@Test
 	public void discoversRepositoryBaseClassMethod() throws Exception {
 
-		Method method = FooRepository.class.getMethod("findOne", Integer.class);
+		Method method = FooRepository.class.getMethod("findById", Integer.class);
 		RepositoryMetadata metadata = new DefaultRepositoryMetadata(FooRepository.class);
 		DefaultRepositoryInformation information = new DefaultRepositoryInformation(metadata, REPOSITORY, Optional.empty());
 
 		Method reference = information.getTargetClassMethod(method);
 		assertThat(reference.getDeclaringClass()).isEqualTo(REPOSITORY);
-		assertThat(reference.getName()).isEqualTo("findOne");
+		assertThat(reference.getName()).isEqualTo("findById");
 	}
 
 	@Test
 	public void discoveresNonRepositoryBaseClassMethod() throws Exception {
 
-		Method method = FooRepository.class.getMethod("findOne", Long.class);
+		Method method = FooRepository.class.getMethod("findById", Long.class);
 
 		RepositoryMetadata metadata = new DefaultRepositoryMetadata(FooRepository.class);
 		DefaultRepositoryInformation information = new DefaultRepositoryInformation(metadata, CrudRepository.class,
@@ -117,7 +116,7 @@ public class DefaultRepositoryInformationUnitTests {
 		Method method = CustomRepository.class.getMethod("findAll", Pageable.class);
 		assertThat(information.isBaseClassMethod(method)).isTrue();
 
-		method = getMethodFrom(CustomRepository.class, "exists");
+		method = getMethodFrom(CustomRepository.class, "existsById");
 
 		assertThat(information.isBaseClassMethod(method)).isTrue();
 		assertThat(information.getQueryMethods()).isEmpty();
@@ -184,7 +183,7 @@ public class DefaultRepositoryInformationUnitTests {
 		RepositoryInformation information = new DefaultRepositoryInformation(metadata, CrudRepository.class,
 				Optional.empty());
 
-		Method method = BaseRepository.class.getMethod("findOne", Serializable.class);
+		Method method = BaseRepository.class.getMethod("findById", Object.class);
 
 		assertThat(information.getQueryMethods()).contains(method);
 	}
@@ -196,8 +195,8 @@ public class DefaultRepositoryInformationUnitTests {
 		RepositoryInformation information = new DefaultRepositoryInformation(metadata, CrudRepository.class,
 				Optional.empty());
 
-		Method method = BossRepository.class.getMethod("save", Iterable.class);
-		Method reference = CrudRepository.class.getMethod("save", Iterable.class);
+		Method method = BossRepository.class.getMethod("saveAll", Iterable.class);
+		Method reference = CrudRepository.class.getMethod("saveAll", Iterable.class);
 
 		assertThat(information.getTargetClassMethod(method)).isEqualTo(reference);
 	}
@@ -268,10 +267,10 @@ public class DefaultRepositoryInformationUnitTests {
 		RepositoryInformation information = new DefaultRepositoryInformation(metadata, DummyRepositoryImpl.class,
 				Optional.empty());
 
-		Method method = DummyRepository.class.getMethod("save", Iterable.class);
+		Method method = DummyRepository.class.getMethod("saveAll", Iterable.class);
 
 		assertThat(information.getTargetClassMethod(method))
-				.isEqualTo(DummyRepositoryImpl.class.getMethod("save", Iterable.class));
+				.isEqualTo(DummyRepositoryImpl.class.getMethod("saveAll", Iterable.class));
 	}
 
 	@Test // DATACMNS-1008, DATACMNS-912, DATACMNS-854
@@ -291,7 +290,7 @@ public class DefaultRepositoryInformationUnitTests {
 		return Arrays.stream(type.getMethods())//
 				.filter(method -> method.getName().equals(name))//
 				.findFirst()//
-				.orElseThrow(() -> new IllegalStateException("No method found wwith name ".concat(name).concat("!")));
+				.orElseThrow(() -> new IllegalStateException("No method found with name ".concat(name).concat("!")));
 	}
 
 	@Target(ElementType.METHOD)
@@ -303,10 +302,10 @@ public class DefaultRepositoryInformationUnitTests {
 	interface FooRepository extends CrudRepository<User, Integer>, FooRepositoryCustom {
 
 		// Redeclared method
-		Optional<User> findOne(Integer primaryKey);
+		Optional<User> findById(Integer primaryKey);
 
 		// Not a redeclared method
-		User findOne(Long primaryKey);
+		User findById(Long primaryKey);
 
 		static void staticMethod() {}
 
@@ -340,7 +339,7 @@ public class DefaultRepositoryInformationUnitTests {
 		}
 	}
 
-	interface BaseRepository<S, ID extends Serializable> extends CrudRepository<S, ID> {
+	interface BaseRepository<S, ID> extends CrudRepository<S, ID> {
 
 		S findBySomething(String something);
 
@@ -351,7 +350,7 @@ public class DefaultRepositoryInformationUnitTests {
 		void delete(S entity);
 
 		@MyQuery
-		Optional<S> findOne(ID id);
+		Optional<S> findById(ID id);
 	}
 
 	interface ConcreteRepository extends BaseRepository<User, Integer> {
@@ -361,9 +360,9 @@ public class DefaultRepositoryInformationUnitTests {
 		User genericMethodToOverride(String something);
 	}
 
-	interface ReadOnlyRepository<T, ID extends Serializable> extends Repository<T, ID> {
+	interface ReadOnlyRepository<T, ID> extends Repository<T, ID> {
 
-		T findOne(ID id);
+		T findById(ID id);
 
 		Iterable<T> findAll();
 
@@ -371,7 +370,7 @@ public class DefaultRepositoryInformationUnitTests {
 
 		List<T> findAll(Sort sort);
 
-		boolean exists(ID id);
+		boolean existsById(ID id);
 
 		long count();
 	}
@@ -405,10 +404,10 @@ public class DefaultRepositoryInformationUnitTests {
 	interface DummyRepository extends CrudRepository<User, Integer> {
 
 		@Override
-		<S extends User> List<S> save(Iterable<S> entites);
+		<S extends User> List<S> saveAll(Iterable<S> entites);
 	}
 
-	static class DummyRepositoryImpl<T, ID extends Serializable> implements CrudRepository<T, ID> {
+	static class DummyRepositoryImpl<T, ID> implements CrudRepository<T, ID> {
 
 		private @Delegate CrudRepository<T, ID> delegate;
 	}

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

@@ -168,7 +168,7 @@ public class DefaultRepositoryMetadataUnitTests {
 
 	static abstract class DummyGenericRepositorySupport<T, ID extends Serializable> implements CrudRepository<T, ID> {
 
-		public java.util.Optional<T> findOne(ID id) {
+		public java.util.Optional<T> findById(ID id) {
 			return java.util.Optional.empty();
 		}
 	}

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

@@ -17,7 +17,6 @@ package org.springframework.data.repository.core.support;
 
 import static org.mockito.Mockito.*;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -61,7 +60,7 @@ public class DummyRepositoryFactory extends RepositoryFactorySupport {
 	 */
 	@Override
 	@SuppressWarnings("unchecked")
-	public <T, ID extends Serializable> EntityInformation<T, ID> getEntityInformation(Class<T> domainClass) {
+	public <T, ID> EntityInformation<T, ID> getEntityInformation(Class<T> domainClass) {
 		return mock(EntityInformation.class);
 	}
 

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

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.core.support;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Set;
 
@@ -36,7 +35,7 @@ public final class DummyRepositoryInformation implements RepositoryInformation {
 		this.metadata = metadata;
 	}
 
-	public Class<? extends Serializable> getIdType() {
+	public Class<?> getIdType() {
 		return metadata.getIdType();
 	}
 

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

@@ -16,12 +16,12 @@
 package org.springframework.data.repository.core.support;
 
 import static org.assertj.core.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
 import static org.mockito.Mockito.*;
 
 import lombok.Getter;
 import lombok.Value;
 
-import java.io.Serializable;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -122,7 +122,7 @@ public class EventPublishingRepositoryProxyPostProcessorUnitTests {
 	@Test // DATACMNS-928
 	public void doesNotInterceptNonSaveMethod() throws Throwable {
 
-		doReturn(SampleRepository.class.getMethod("findOne", Serializable.class)).when(invocation).getMethod();
+		doReturn(SampleRepository.class.getMethod("findById", Object.class)).when(invocation).getMethod();
 
 		EventPublishingMethodInterceptor//
 				.of(EventPublishingMethod.of(MultipleEvents.class), publisher)//
@@ -164,7 +164,7 @@ public class EventPublishingRepositoryProxyPostProcessorUnitTests {
 		MultipleEvents sample = MultipleEvents.of(Collections.singletonList(event));
 		doReturn(new Object[] { Collections.singletonList(sample) }).when(invocation).getArguments();
 
-		doReturn(SampleRepository.class.getMethod("save", Iterable.class)).when(invocation).getMethod();
+		doReturn(SampleRepository.class.getMethod("saveAll", Iterable.class)).when(invocation).getMethod();
 
 		EventPublishingMethodInterceptor//
 				.of(EventPublishingMethod.of(MultipleEvents.class), publisher)//

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

@@ -22,7 +22,6 @@ import io.reactivex.Flowable;
 import reactor.core.publisher.Flux;
 import rx.Observable;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Optional;
 
@@ -60,10 +59,11 @@ public class ReactiveRepositoryInformationUnitTests {
 	@Test // DATACMNS-836
 	public void discoversRxJava1MethodWithConvertibleArguments() throws Exception {
 
-		Method reference = extractTargetMethodFromRepository(RxJava1InterfaceWithGenerics.class, "save", Observable.class);
+		Method reference = extractTargetMethodFromRepository(RxJava1InterfaceWithGenerics.class, "saveAll",
+				Observable.class);
 
 		assertEquals(ReactiveCrudRepository.class, reference.getDeclaringClass());
-		assertThat(reference.getName(), is("save"));
+		assertThat(reference.getName(), is("saveAll"));
 		assertThat(reference.getParameterTypes()[0], is(equalTo(Publisher.class)));
 	}
 
@@ -79,31 +79,31 @@ public class ReactiveRepositoryInformationUnitTests {
 	@Test // DATACMNS-988
 	public void discoversRxJava2MethodWithConvertibleArguments() throws Exception {
 
-		Method reference = extractTargetMethodFromRepository(RxJava2InterfaceWithGenerics.class, "save", Flowable.class);
+		Method reference = extractTargetMethodFromRepository(RxJava2InterfaceWithGenerics.class, "saveAll", Flowable.class);
 
 		assertEquals(ReactiveCrudRepository.class, reference.getDeclaringClass());
-		assertThat(reference.getName(), is("save"));
+		assertThat(reference.getName(), is("saveAll"));
 		assertThat(reference.getParameterTypes()[0], is(equalTo(Publisher.class)));
 	}
 
 	@Test // DATACMNS-836
 	public void discoversMethodAssignableArguments() throws Exception {
 
-		Method reference = extractTargetMethodFromRepository(ReactiveSortingRepository.class, "save", Publisher.class);
+		Method reference = extractTargetMethodFromRepository(ReactiveSortingRepository.class, "saveAll", Publisher.class);
 
 		assertEquals(ReactiveCrudRepository.class, reference.getDeclaringClass());
-		assertThat(reference.getName(), is("save"));
+		assertThat(reference.getName(), is("saveAll"));
 		assertThat(reference.getParameterTypes()[0], is(equalTo(Publisher.class)));
 	}
 
 	@Test // DATACMNS-836
 	public void discoversMethodExactIterableArguments() throws Exception {
 
-		Method reference = extractTargetMethodFromRepository(ReactiveJavaInterfaceWithGenerics.class, "save",
+		Method reference = extractTargetMethodFromRepository(ReactiveJavaInterfaceWithGenerics.class, "saveAll",
 				Iterable.class);
 
 		assertEquals(ReactiveCrudRepository.class, reference.getDeclaringClass());
-		assertThat(reference.getName(), is("save"));
+		assertThat(reference.getName(), is("saveAll"));
 		assertThat(reference.getParameterTypes()[0], is(equalTo(Iterable.class)));
 	}
 
@@ -120,12 +120,12 @@ public class ReactiveRepositoryInformationUnitTests {
 	@Test // DATACMNS-1023
 	public void usesCorrectSaveOverload() throws Exception {
 
-		Method reference = extractTargetMethodFromRepository(DummyRepository.class, "save", Iterable.class);
+		Method reference = extractTargetMethodFromRepository(DummyRepository.class, "saveAll", Iterable.class);
 
-		assertThat(reference, is(ReactiveCrudRepository.class.getMethod("save", Iterable.class)));
+		assertThat(reference, is(ReactiveCrudRepository.class.getMethod("saveAll", Iterable.class)));
 	}
 
-	private Method extractTargetMethodFromRepository(Class<?> repositoryType, String methodName, Class... args)
+	private Method extractTargetMethodFromRepository(Class<?> repositoryType, String methodName, Class<?>... args)
 			throws NoSuchMethodException {
 
 		RepositoryInformation information = new ReactiveRepositoryInformation(new DefaultRepositoryMetadata(repositoryType),
@@ -139,15 +139,14 @@ public class ReactiveRepositoryInformationUnitTests {
 
 	interface ReactiveJavaInterfaceWithGenerics extends ReactiveCrudRepository<User, String> {}
 
-	static abstract class DummyGenericReactiveRepositorySupport<T, ID extends Serializable>
-			implements ReactiveCrudRepository<T, ID> {
+	static abstract class DummyGenericReactiveRepositorySupport<T, ID> implements ReactiveCrudRepository<T, ID> {
 
 	}
 
 	interface DummyRepository extends ReactiveCrudRepository<User, Integer> {
 
 		@Override
-		<S extends User> Flux<S> save(Iterable<S> entities);
+		<S extends User> Flux<S> saveAll(Iterable<S> entities);
 	}
 
 	static class User {

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

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.repository.core.support;
 
+import static org.mockito.ArgumentMatchers.*;
 import static org.mockito.Mockito.*;
 
 import io.reactivex.Completable;
@@ -59,10 +60,10 @@ public class ReactiveWrapperRepositoryFactorySupportUnitTests {
 	public void invokesCustomMethodIfItRedeclaresACRUDOne() {
 
 		ObjectRepository repository = factory.getRepository(ObjectRepository.class, customImplementation);
-		repository.findOne(1);
+		repository.findById(1);
 
-		verify(customImplementation, times(1)).findOne(1);
-		verify(backingRepo, times(0)).findOne(1);
+		verify(customImplementation, times(1)).findById(1);
+		verify(backingRepo, times(0)).findById(1);
 	}
 
 	@Test // DATACMNS-836
@@ -70,10 +71,10 @@ public class ReactiveWrapperRepositoryFactorySupportUnitTests {
 
 		Serializable id = 1L;
 		RxJava1ConvertingRepository repository = factory.getRepository(RxJava1ConvertingRepository.class);
-		repository.exists(id);
-		repository.exists((Long) id);
+		repository.existsById(id);
+		repository.existsById((Long) id);
 
-		verify(backingRepo, times(2)).exists(id);
+		verify(backingRepo, times(2)).existsById(id);
 	}
 
 	@Test // DATACMNS-836
@@ -83,9 +84,9 @@ public class ReactiveWrapperRepositoryFactorySupportUnitTests {
 		Single<Long> ids = Single.just(1L);
 
 		RxJava1ConvertingRepository repository = factory.getRepository(RxJava1ConvertingRepository.class);
-		repository.exists(ids);
+		repository.existsById(ids);
 
-		verify(backingRepo, times(1)).exists(any(Mono.class));
+		verify(backingRepo, times(1)).existsById(any(Mono.class));
 	}
 
 	@Test // DATACMNS-988
@@ -93,9 +94,9 @@ public class ReactiveWrapperRepositoryFactorySupportUnitTests {
 
 		Long id = 1L;
 		RxJava2ConvertingRepository repository = factory.getRepository(RxJava2ConvertingRepository.class);
-		repository.findOne(id);
+		repository.findById(id);
 
-		verify(backingRepo, times(1)).findOne(id);
+		verify(backingRepo, times(1)).findById(id);
 	}
 
 	@Test // DATACMNS-988
@@ -104,36 +105,36 @@ public class ReactiveWrapperRepositoryFactorySupportUnitTests {
 		Serializable id = 1L;
 
 		RxJava2ConvertingRepository repository = factory.getRepository(RxJava2ConvertingRepository.class);
-		repository.delete(id);
+		repository.deleteById(id);
 
-		verify(backingRepo, times(1)).delete(id);
+		verify(backingRepo, times(1)).deleteById(id);
 	}
 
 	interface RxJava1ConvertingRepository extends Repository<Object, Long> {
 
-		Single<Boolean> exists(Single<Long> id);
+		Single<Boolean> existsById(Single<Long> id);
 
-		Single<Boolean> exists(Serializable id);
+		Single<Boolean> existsById(Serializable id);
 
-		Single<Boolean> exists(Long id);
+		Single<Boolean> existsById(Long id);
 	}
 
 	interface RxJava2ConvertingRepository extends Repository<Object, Long> {
 
-		Maybe<Boolean> findOne(Serializable id);
+		Maybe<Boolean> findById(Serializable id);
 
-		Single<Boolean> exists(Long id);
+		Single<Boolean> existsById(Long id);
 
-		Completable delete(Serializable id);
+		Completable deleteById(Serializable id);
 	}
 
 	interface ObjectRepository
-			extends Repository<Object, Serializable>, RepositoryFactorySupportUnitTests.ObjectRepositoryCustom {
+			extends Repository<Object, Object>, RepositoryFactorySupportUnitTests.ObjectRepositoryCustom {
 
 	}
 
 	interface ObjectRepositoryCustom {
 
-		Object findOne(Serializable id);
+		Object findById(Object id);
 	}
 }

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

@@ -22,9 +22,9 @@ import static org.mockito.Mockito.*;
 
 import java.io.Serializable;
 import java.lang.reflect.Method;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
@@ -77,7 +77,7 @@ public class RepositoryFactorySupportUnitTests {
 
 	DummyRepositoryFactory factory;
 
-	@Mock PagingAndSortingRepository<Object, Serializable> backingRepo;
+	@Mock PagingAndSortingRepository<Object, Object> backingRepo;
 	@Mock ObjectRepositoryCustom customImplementation;
 
 	@Mock MyQueryCreationListener listener;
@@ -119,10 +119,10 @@ public class RepositoryFactorySupportUnitTests {
 	public void invokesCustomMethodIfItRedeclaresACRUDOne() {
 
 		ObjectRepository repository = factory.getRepository(ObjectRepository.class, customImplementation);
-		repository.findOne(1);
+		repository.findById(1);
 
-		verify(customImplementation, times(1)).findOne(1);
-		verify(backingRepo, times(0)).findOne(1);
+		verify(customImplementation, times(1)).findById(1);
+		verify(backingRepo, times(0)).findById(1);
 	}
 
 	@Test
@@ -316,7 +316,7 @@ public class RepositoryFactorySupportUnitTests {
 
 	interface SimpleRepository extends Repository<Object, Serializable> {}
 
-	interface ObjectRepository extends Repository<Object, Serializable>, ObjectRepositoryCustom {
+	interface ObjectRepository extends Repository<Object, Object>, ObjectRepositoryCustom {
 
 		Object findByClass(Class<?> clazz);
 
@@ -335,7 +335,7 @@ public class RepositoryFactorySupportUnitTests {
 
 	interface ObjectRepositoryCustom {
 
-		Object findOne(Serializable id);
+		Object findById(Object id);
 	}
 
 	interface PlainQueryCreationListener extends QueryCreationListener<RepositoryQuery> {
@@ -352,7 +352,7 @@ public class RepositoryFactorySupportUnitTests {
 
 	interface ReadOnlyRepository<T, ID extends Serializable> extends Repository<T, ID> {
 
-		T findOne(ID id);
+		Optional<T> findById(ID id);
 
 		Iterable<T> findAll();
 
@@ -360,7 +360,7 @@ public class RepositoryFactorySupportUnitTests {
 
 		List<T> findAll(Sort sort);
 
-		boolean exists(ID id);
+		boolean existsById(ID id);
 
 		long count();
 	}

src/test/java/org/springframework/data/repository/sample/ProductRepository.java

@@ -4,7 +4,7 @@ import org.springframework.data.repository.Repository;
 
 public interface ProductRepository extends Repository<Product, Long> {
 
-	Product findOne(Long id);
+	Product findById(Long id);
 
 	Product save(Product product);
 }

src/test/java/org/springframework/data/repository/support/CrudRepositoryInvokerUnitTests.java

@@ -18,7 +18,6 @@ package org.springframework.data.repository.support;
 import static org.mockito.Mockito.*;
 import static org.springframework.data.repository.support.RepositoryInvocationTestUtils.*;
 
-import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.Date;
@@ -62,12 +61,12 @@ public class CrudRepositoryInvokerUnitTests {
 
 	@Test // DATACMNS-589, DATAREST-216
 	public void invokesRedeclaredFindOne() {
-		getInvokerFor(orderRepository, expectInvocationOnType(OrderRepository.class)).invokeFindOne(1L);
+		getInvokerFor(orderRepository, expectInvocationOnType(OrderRepository.class)).invokeFindById(1L);
 	}
 
 	@Test // DATACMNS-589
 	public void invokesRedeclaredDelete() throws Exception {
-		getInvokerFor(orderRepository, expectInvocationOnType(OrderRepository.class)).invokeDelete(1L);
+		getInvokerFor(orderRepository, expectInvocationOnType(OrderRepository.class)).invokeDeleteById(1L);
 	}
 
 	@Test // DATACMNS-589
@@ -80,15 +79,15 @@ public class CrudRepositoryInvokerUnitTests {
 	@Test // DATACMNS-589
 	public void invokesFindOneOnCrudRepository() throws Exception {
 
-		Method method = CrudRepository.class.getMethod("findOne", Serializable.class);
-		getInvokerFor(personRepository, expectInvocationOf(method)).invokeFindOne(1L);
+		Method method = CrudRepository.class.getMethod("findById", Object.class);
+		getInvokerFor(personRepository, expectInvocationOf(method)).invokeFindById(1L);
 	}
 
 	@Test // DATACMNS-589, DATAREST-216
 	public void invokesDeleteOnCrudRepository() throws Exception {
 
-		Method method = CrudRepository.class.getMethod("delete", Serializable.class);
-		getInvokerFor(personRepository, expectInvocationOf(method)).invokeDelete(1L);
+		Method method = CrudRepository.class.getMethod("deleteById", Object.class);
+		getInvokerFor(personRepository, expectInvocationOf(method)).invokeDeleteById(1L);
 	}
 
 	@Test // DATACMNS-589
@@ -142,10 +141,10 @@ public class CrudRepositoryInvokerUnitTests {
 		<S extends Order> S save(S entity);
 
 		@Override
-		Optional<Order> findOne(Long id);
+		Optional<Order> findById(Long id);
 
 		@Override
-		void delete(Long id);
+		void deleteById(Long id);
 	}
 
 	static class Person {}
@@ -172,6 +171,6 @@ public class CrudRepositoryInvokerUnitTests {
 
 	interface CrudWithRedeclaredDelete extends CrudRepository<Order, Long> {
 
-		void delete(Long id);
+		void deleteById(Long id);
 	}
 }

src/test/java/org/springframework/data/repository/support/DefaultRepositoryInvokerFactoryIntegrationTests.java

@@ -59,9 +59,9 @@ public class DefaultRepositoryInvokerFactoryIntegrationTests {
 
 		// Mockito.reset(productRepository);
 		Product product = new Product();
-		when(productRepository.findOne(4711L)).thenReturn(product);
+		when(productRepository.findById(4711L)).thenReturn(product);
 
-		Optional<Object> invokeFindOne = factory.getInvokerFor(Product.class).invokeFindOne(4711L);
+		Optional<Object> invokeFindOne = factory.getInvokerFor(Product.class).invokeFindById(4711L);
 
 		assertThat(invokeFindOne).isEqualTo(Optional.of(product));
 	}

src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java

@@ -121,7 +121,7 @@ public class DomainClassConverterUnitTests {
 		UserRepository bean = context.getBean(UserRepository.class);
 		UserRepository repo = (UserRepository) ((Advised) bean).getTargetSource().getTarget();
 
-		verify(repo, times(1)).findOne(1L);
+		verify(repo, times(1)).findById(1L);
 	}
 
 	@Test // DATACMNS-133

src/test/java/org/springframework/data/repository/support/ReflectionRepositoryInvokerUnitTests.java

@@ -82,22 +82,22 @@ public class ReflectionRepositoryInvokerUnitTests {
 	public void invokesFindOneCorrectly() throws Exception {
 
 		ManualCrudRepository repository = mock(ManualCrudRepository.class);
-		Method method = ManualCrudRepository.class.getMethod("findOne", Long.class);
+		Method method = ManualCrudRepository.class.getMethod("findById", Long.class);
 
-		getInvokerFor(repository, expectInvocationOf(method)).invokeFindOne("1");
-		getInvokerFor(repository, expectInvocationOf(method)).invokeFindOne(1L);
+		getInvokerFor(repository, expectInvocationOf(method)).invokeFindById("1");
+		getInvokerFor(repository, expectInvocationOf(method)).invokeFindById(1L);
 	}
 
 	@Test // DATACMNS-589
 	public void invokesDeleteWithDomainCorrectly() throws Exception {
 
 		RepoWithDomainDeleteAndFindOne repository = mock(RepoWithDomainDeleteAndFindOne.class);
-		when(repository.findOne(1L)).thenReturn(new Domain());
+		when(repository.findById(1L)).thenReturn(new Domain());
 
-		Method findOneMethod = RepoWithDomainDeleteAndFindOne.class.getMethod("findOne", Long.class);
+		Method findOneMethod = RepoWithDomainDeleteAndFindOne.class.getMethod("findById", Long.class);
 		Method deleteMethod = RepoWithDomainDeleteAndFindOne.class.getMethod("delete", Domain.class);
 
-		getInvokerFor(repository, expectInvocationOf(findOneMethod, deleteMethod)).invokeDelete(1L);
+		getInvokerFor(repository, expectInvocationOf(findOneMethod, deleteMethod)).invokeDeleteById(1L);
 	}
 
 	@Test // DATACMNS-589
@@ -164,9 +164,9 @@ public class ReflectionRepositoryInvokerUnitTests {
 	public void invokesOverriddenDeleteMethodCorrectly() throws Exception {
 
 		MyRepo repository = mock(MyRepo.class);
-		Method method = CustomRepo.class.getMethod("delete", Long.class);
+		Method method = CustomRepo.class.getMethod("deleteById", Long.class);
 
-		getInvokerFor(repository, expectInvocationOf(method)).invokeDelete("1");
+		getInvokerFor(repository, expectInvocationOf(method)).invokeDeleteById("1");
 	}
 
 	@Test(expected = IllegalStateException.class) // DATACMNS-589
@@ -175,7 +175,7 @@ public class ReflectionRepositoryInvokerUnitTests {
 		RepositoryInvoker invoker = getInvokerFor(mock(EmptyRepository.class));
 
 		assertThat(invoker.hasDeleteMethod()).isFalse();
-		invoker.invokeDelete(1L);
+		invoker.invokeDeleteById(1L);
 	}
 
 	@Test(expected = IllegalStateException.class) // DATACMNS-589
@@ -184,7 +184,7 @@ public class ReflectionRepositoryInvokerUnitTests {
 		RepositoryInvoker invoker = getInvokerFor(mock(EmptyRepository.class));
 
 		assertThat(invoker.hasFindOneMethod()).isFalse();
-		invoker.invokeFindOne(1L);
+		invoker.invokeFindById(1L);
 	}
 
 	@Test(expected = IllegalStateException.class) // DATACMNS-589
@@ -245,11 +245,11 @@ public class ReflectionRepositoryInvokerUnitTests {
 	public void convertsWrapperTypeToJdkOptional() {
 
 		GuavaRepository mock = mock(GuavaRepository.class);
-		when(mock.findOne(any())).thenReturn(com.google.common.base.Optional.of(new Domain()));
+		when(mock.findById(any())).thenReturn(com.google.common.base.Optional.of(new Domain()));
 
 		RepositoryInvoker invoker = getInvokerFor(mock);
 
-		Optional<Object> invokeFindOne = invoker.invokeFindOne(1L);
+		Optional<Object> invokeFindOne = invoker.invokeFindById(1L);
 
 		assertThat(invokeFindOne).isPresent();
 	}
@@ -262,8 +262,8 @@ public class ReflectionRepositoryInvokerUnitTests {
 
 		Method method = ManualCrudRepository.class.getMethod("findAll");
 
-		Optional<Object> result = getInvokerFor(mock).invokeQueryMethod(method, new LinkedMultiValueMap<>(), Pageable.unpaged(),
-				Sort.unsorted());
+		Optional<Object> result = getInvokerFor(mock).invokeQueryMethod(method, new LinkedMultiValueMap<>(),
+				Pageable.unpaged(), Sort.unsorted());
 
 		assertThat(result).hasValueSatisfying(it -> {
 			assertThat(it).isInstanceOf(Collection.class);
@@ -287,20 +287,20 @@ public class ReflectionRepositoryInvokerUnitTests {
 	class Domain {}
 
 	interface CustomRepo {
-		void delete(Long id);
+		void deleteById(Long id);
 	}
 
 	interface EmptyRepository extends Repository<Domain, Long> {}
 
 	interface ManualCrudRepository extends Repository<Domain, Long> {
 
-		Domain findOne(Long id);
+		Domain findById(Long id);
 
 		Iterable<Domain> findAll();
 
 		<T extends Domain> T save(T entity);
 
-		void delete(Long id);
+		void deleteById(Long id);
 	}
 
 	interface RepoWithFindAllWithoutParameters extends Repository<Domain, Long> {
@@ -320,7 +320,7 @@ public class ReflectionRepositoryInvokerUnitTests {
 
 	interface RepoWithDomainDeleteAndFindOne extends Repository<Domain, Long> {
 
-		Domain findOne(Long id);
+		Domain findById(Long id);
 
 		void delete(Domain entity);
 	}
@@ -332,6 +332,6 @@ public class ReflectionRepositoryInvokerUnitTests {
 
 	interface GuavaRepository extends Repository<Domain, Long> {
 
-		com.google.common.base.Optional<Domain> findOne(Long id);
+		com.google.common.base.Optional<Domain> findById(Long id);
 	}
 }