Polishing.

Let List… interface variants extend their base parent so that List-based variants participate in the type hierarchy.

See #2538
Original pull request: #2538.

Author: mp911de

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

@@ -16,36 +16,21 @@
 package org.springframework.data.querydsl;
 
 import java.util.List;
-import java.util.Optional;
-import java.util.function.Function;
 
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
-import org.springframework.data.repository.query.FluentQuery;
 
 import com.querydsl.core.types.OrderSpecifier;
 import com.querydsl.core.types.Predicate;
 
 /**
- * Interface to allow execution of QueryDsl {@link Predicate} instances.This identical to *
- * {@link QuerydslPredicateExecutor} but returns {@link List} instead of {@link Iterable} where applicable.
+ * Interface to allow execution of QueryDsl {@link Predicate} instances. This an extension to
+ * {@link QuerydslPredicateExecutor} returning {@link List} instead of {@link Iterable} where applicable.
  *
  * @author Jens Schauder
  * @since 3.0
  * @see QuerydslPredicateExecutor
  */
-public interface ListQuerydslPredicateExecutor<T> {
-
-	/**
-	 * Returns a single entity matching the given {@link Predicate} or {@link Optional#empty()} if none was found.
-	 *
-	 * @param predicate must not be {@literal null}.
-	 * @return a single entity matching the given {@link Predicate} or {@link Optional#empty()} if none was found.
-	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if the predicate yields more than one
-	 *           result.
-	 */
-	Optional<T> findOne(Predicate predicate);
+public interface ListQuerydslPredicateExecutor<T> extends QuerydslPredicateExecutor<T> {
 
 	/**
 	 * Returns all entities matching the given {@link Predicate}. In case no match could be found an empty {@link List} is
@@ -54,6 +39,7 @@ public interface ListQuerydslPredicateExecutor<T> {
 	 * @param predicate must not be {@literal null}.
 	 * @return all entities matching the given {@link Predicate}.
 	 */
+	@Override
 	List<T> findAll(Predicate predicate);
 
 	/**
@@ -65,6 +51,7 @@ public interface ListQuerydslPredicateExecutor<T> {
 	 *          {@literal null}.
 	 * @return all entities matching the given {@link Predicate}.
 	 */
+	@Override
 	List<T> findAll(Predicate predicate, Sort sort);
 
 	/**
@@ -75,6 +62,7 @@ public interface ListQuerydslPredicateExecutor<T> {
 	 * @param orders the {@link OrderSpecifier}s to sort the results by, must not be {@literal null}.
 	 * @return all entities matching the given {@link Predicate} applying the given {@link OrderSpecifier}s.
 	 */
+	@Override
 	List<T> findAll(Predicate predicate, OrderSpecifier<?>... orders);
 
 	/**
@@ -83,41 +71,7 @@ public interface ListQuerydslPredicateExecutor<T> {
 	 * @param orders the {@link OrderSpecifier}s to sort the results by, must not be {@literal null}.
 	 * @return all entities ordered by the given {@link OrderSpecifier}s.
 	 */
+	@Override
 	List<T> findAll(OrderSpecifier<?>... orders);
 
-	/**
-	 * Returns a {@link Page} of entities matching the given {@link Predicate}. In case no match could be found, an empty
-	 * {@link Page} is returned.
-	 *
-	 * @param predicate must not be {@literal null}.
-	 * @param pageable may be {@link Pageable#unpaged()}, must not be {@literal null}.
-	 * @return a {@link Page} of entities matching the given {@link Predicate}.
-	 */
-	Page<T> findAll(Predicate predicate, Pageable pageable);
-
-	/**
-	 * Returns the number of instances matching the given {@link Predicate}.
-	 *
-	 * @param predicate the {@link Predicate} to count instances for, must not be {@literal null}.
-	 * @return the number of instances matching the {@link Predicate}.
-	 */
-	long count(Predicate predicate);
-
-	/**
-	 * Checks whether the data store contains elements that match the given {@link Predicate}.
-	 *
-	 * @param predicate the {@link Predicate} to use for the existence check, must not be {@literal null}.
-	 * @return {@literal true} if the data store contains elements that match the given {@link Predicate}.
-	 */
-	boolean exists(Predicate predicate);
-
-	/**
-	 * Returns entities matching the given {@link Predicate} applying the {@link Function queryFunction} that defines the
-	 * query and its result type.
-	 *
-	 * @param predicate must not be {@literal null}.
-	 * @param queryFunction the query function defining projection, sorting, and the result type
-	 * @return all entities matching the given {@link Predicate}.
-	 */
-	<S extends T, R> R findBy(Predicate predicate, Function<FluentQuery.FetchableFluentQuery<S>, R> queryFunction);
 }

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

@@ -33,6 +33,7 @@
  * @author Thomas Darimont
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @see ListQuerydslPredicateExecutor
  */
 public interface QuerydslPredicateExecutor<T> {
 

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

@@ -16,28 +16,17 @@
 package org.springframework.data.repository;
 
 import java.util.List;
-import java.util.Optional;
 
 /**
- * Interface for generic CRUD operations on a repository for a specific type. This identical to {@link CrudRepository}
- * but returns {@link List} instead of {@link Iterable} where applicable.
- * 
+ * Interface for generic CRUD operations on a repository for a specific type. This an extension to
+ * {@link CrudRepository} returning {@link List} instead of {@link Iterable} where applicable.
+ *
  * @author Jens Schauder
  * @see CrudRepository
  * @since 3.0
  */
 @NoRepositoryBean
-public interface ListCrudRepository<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 must not be {@literal null}.
-	 * @return the saved entity; will never be {@literal null}.
-	 * @throws IllegalArgumentException in case the given {@literal entity} is {@literal null}.
-	 */
-	<S extends T> S save(S entity);
+public interface ListCrudRepository<T, ID> extends CrudRepository<T, ID> {
 
 	/**
 	 * Saves all given entities.
@@ -50,24 +39,6 @@ public interface ListCrudRepository<T, ID> extends Repository<T, ID> {
 	 */
 	<S extends T> List<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 Optional#empty()} if none found.
-	 * @throws IllegalArgumentException if {@literal id} is {@literal null}.
-	 */
-	Optional<T> findById(ID id);
-
-	/**
-	 * Returns whether an entity with the given id exists.
-	 *
-	 * @param id must not be {@literal null}.
-	 * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
-	 * @throws IllegalArgumentException if {@literal id} is {@literal null}.
-	 */
-	boolean existsById(ID id);
-
 	/**
 	 * Returns all instances of the type.
 	 *
@@ -89,47 +60,4 @@ public interface ListCrudRepository<T, ID> extends Repository<T, ID> {
 	 */
 	List<T> findAllById(Iterable<ID> ids);
 
-	/**
-	 * Returns the number of entities available.
-	 *
-	 * @return the number of entities.
-	 */
-	long count();
-
-	/**
-	 * Deletes the entity with the given id.
-	 *
-	 * @param id must not be {@literal null}.
-	 * @throws IllegalArgumentException in case the given {@literal id} is {@literal null}
-	 */
-	void deleteById(ID id);
-
-	/**
-	 * Deletes a given entity.
-	 *
-	 * @param entity must not be {@literal null}.
-	 * @throws IllegalArgumentException in case the given entity is {@literal null}.
-	 */
-	void delete(T entity);
-
-	/**
-	 * Deletes all instances of the type {@code T} with the given IDs.
-	 *
-	 * @param ids must not be {@literal null}. Must not contain {@literal null} elements.
-	 * @throws IllegalArgumentException in case the given {@literal ids} or one of its elements is {@literal null}.
-	 */
-	void deleteAllById(Iterable<? extends ID> ids);
-
-	/**
-	 * Deletes the given entities.
-	 *
-	 * @param entities must not be {@literal null}. Must not contain {@literal null} elements.
-	 * @throws IllegalArgumentException in case the given {@literal entities} or one of its entities is {@literal null}.
-	 */
-	void deleteAll(Iterable<? extends T> entities);
-
-	/**
-	 * Deletes all entities managed by the repository.
-	 */
-	void deleteAll();
 }

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

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2008-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.repository;
+
+import java.util.List;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+
+/**
+ * Repository fragment to provide methods to retrieve entities using the pagination and sorting abstraction. This an
+ * extension to {@link PagingAndSortingRepository} returning {@link List} instead of {@link Iterable} where applicable.
+ *
+ * @author Oliver Gierke
+ * @author Jens Schauder
+ * @see Sort
+ * @see Pageable
+ * @see Page
+ * @see CrudRepository
+ */
+@NoRepositoryBean
+public interface ListPagingAndSortingRepository<T, ID> extends PagingAndSortingRepository<T, ID> {
+
+	/**
+	 * Returns all entities sorted by the given options.
+	 *
+	 * @param sort
+	 * @return all entities sorted by the given options
+	 */
+	List<T> findAll(Sort sort);
+
+}

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

@@ -16,33 +16,20 @@
 package org.springframework.data.repository.query;
 
 import java.util.List;
-import java.util.Optional;
-import java.util.function.Function;
 
 import org.springframework.data.domain.Example;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 
 /**
- * Interface to allow execution of Query by Example {@link Example} instances. This identical to
- * {@link QueryByExampleExecutor} but returns {@link List} instead of {@link Iterable} where applicable.
+ * Interface to allow execution of Query by Example {@link Example} instances. This an extension to
+ * {@link QueryByExampleExecutor} returning {@link List} instead of {@link Iterable} where applicable.
  *
  * @param <T> the type of entity for which this executor acts on.
  * @author Jens Schauder
  * @since 3.0
  * @see QueryByExampleExecutor
  */
-public interface ListQueryByExampleExecutor<T> {
-
-	/**
-	 * Returns a single entity matching the given {@link Example} or {@link Optional#empty()} if none was found.
-	 *
-	 * @param example must not be {@literal null}.
-	 * @return a single entity matching the given {@link Example} or {@link Optional#empty()} if none was found.
-	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if the Example yields more than one result.
-	 */
-	<S extends T> Optional<S> findOne(Example<S> example);
+public interface ListQueryByExampleExecutor<T> extends QueryByExampleExecutor<T> {
 
 	/**
 	 * Returns all entities matching the given {@link Example}. In case no match could be found an empty {@link List} is
@@ -51,6 +38,7 @@ public interface ListQueryByExampleExecutor<T> {
 	 * @param example must not be {@literal null}.
 	 * @return all entities matching the given {@link Example}.
 	 */
+	@Override
 	<S extends T> List<S> findAll(Example<S> example);
 
 	/**
@@ -61,41 +49,7 @@ public interface ListQueryByExampleExecutor<T> {
 	 * @param sort the {@link Sort} specification to sort the results by, must not be {@literal null}.
 	 * @return all entities matching the given {@link Example}.
 	 */
+	@Override
 	<S extends T> List<S> findAll(Example<S> example, Sort sort);
 
-	/**
-	 * Returns a {@link Page} of entities matching the given {@link Example}. In case no match could be found, an empty
-	 * {@link Page} is returned.
-	 *
-	 * @param example must not be {@literal null}.
-	 * @param pageable can be {@literal null}.
-	 * @return a {@link Page} of entities matching the given {@link Example}.
-	 */
-	<S extends T> Page<S> findAll(Example<S> example, Pageable pageable);
-
-	/**
-	 * Returns the number of instances matching the given {@link Example}.
-	 *
-	 * @param example the {@link Example} to count instances for. Must not be {@literal null}.
-	 * @return the number of instances matching the {@link Example}.
-	 */
-	<S extends T> long count(Example<S> example);
-
-	/**
-	 * Checks whether the data store contains elements that match the given {@link Example}.
-	 *
-	 * @param example the {@link Example} to use for the existence check. Must not be {@literal null}.
-	 * @return {@literal true} if the data store contains elements that match the given {@link Example}.
-	 */
-	<S extends T> boolean exists(Example<S> example);
-
-	/**
-	 * Returns entities matching the given {@link Example} applying the {@link Function queryFunction} that defines the
-	 * query and its result type.
-	 *
-	 * @param example must not be {@literal null}.
-	 * @param queryFunction the query function defining projection, sorting, and the result type
-	 * @return all entities matching the given {@link Example}.
-	 */
-	<S extends T, R> R findBy(Example<S> example, Function<FluentQuery.FetchableFluentQuery<S>, R> queryFunction);
 }

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

@@ -30,6 +30,7 @@
  * @author Mark Paluch
  * @author Christoph Strobl
  * @since 1.12
+ * @see ListQueryByExampleExecutor
  */
 public interface QueryByExampleExecutor<T> {