/*

 * Copyright 2008-2022 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.Optional;

​

/**

 * Interface for generic CRUD operations on a repository for a specific type.

 *

 * @author Oliver Gierke

 * @author Eberhard Wolff

 * @author Jens Schauder

 */

@NoRepositoryBean

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 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);

​

    /**

     * Saves all given entities.

     *

     * @param entities must not be {@literal null} nor must it contain {@literal null}.

     * @return the saved entities; will never be {@literal null}. The returned {@literal Iterable} will have the same size

     *         as the {@literal Iterable} passed as an argument.

     * @throws IllegalArgumentException in case the given {@link Iterable entities} or one of its entities is

     *           {@literal null}.

     */

    <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 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.

     *

     * @return all entities

     */

    Iterable<T> findAll();

​

    /**

     * Returns all instances of the type {@code T} with the given IDs.

     * <p>

     * If some or all ids are not found, no entities are returned for these IDs.

     * <p>

     * Note that the order of elements in the result is not guaranteed.

     *

     * @param ids must not be {@literal null} nor contain any {@literal null} values.

     * @return guaranteed to be not {@literal null}. The size can be equal or less than the number of given

     *         {@literal ids}.

     * @throws IllegalArgumentException in case the given {@link Iterable ids} or one of its items is {@literal null}.

     */

    Iterable<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}.

     * @since 2.5

     */

    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();

}

​