Interfaces Repository

Repository

/**
 * Central repository marker interface. Captures the domain type to manage as well as the domain type's id type. General
 * purpose is to hold type information as well as being able to discover interfaces that extend this one during
 * classpath scanning for easy Spring bean creation.
 * <p>
 * Domain repositories extending this interface can selectively expose CRUD methods by simply declaring methods of the
 * same signature as those declared in {@link CrudRepository}.
 * 
 * @see CrudRepository
 * @param <T> the domain type the repository manages
 * @param <ID> the type of the id of the entity the repository manages
 * @author Oliver Gierke
 */
@Indexed
public interface Repository<T, ID> {

}

CrudRepository

/**
 * Interface for generic CRUD operations on a repository for a specific type.
 * 
 * @author Oliver Gierke
 * @author Eberhard Wolff
 */
@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}.
     */
    <S extends T> S save(S entity);

    /**
     * Saves all given 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> 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 {@code 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 {@code 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 with the given IDs.
     * 
     * @param ids
     * @return
     */
    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 {@code id} is {@literal null}
     */
    void deleteById(ID id);

    /**
     * Deletes a given entity.
     * 
     * @param entity
     * @throws IllegalArgumentException in case the given entity is {@literal null}.
     */
    void delete(T entity);

    /**
     * Deletes the given entities.
     * 
     * @param entities
     * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
     */
    void deleteAll(Iterable<? extends T> entities);

    /**
     * Deletes all entities managed by the repository.
     */
    void deleteAll();
}

PagingAndSortingRepository

/**
 * Extension of {@link CrudRepository} to provide additional methods to retrieve entities using the pagination and
 * sorting abstraction.
 * 
 * @author Oliver Gierke
 * @see Sort
 * @see Pageable
 * @see Page
 */
@NoRepositoryBean
public interface PagingAndSortingRepository<T, ID> extends CrudRepository<T, ID> {

    /**
     * Returns all entities sorted by the given options.
     * 
     * @param sort
     * @return all entities sorted by the given options
     */
    Iterable<T> findAll(Sort sort);

    /**
     * Returns a {@link Page} of entities meeting the paging restriction provided in the {@code Pageable} object.
     * 
     * @param pageable
     * @return a page of entities
     */
    Page<T> findAll(Pageable pageable);
}