universe@34: /*
universe@34:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@34:  *
universe@34:  * Copyright 2018 Mike Becker. All rights reserved.
universe@34:  *
universe@34:  * Redistribution and use in source and binary forms, with or without
universe@34:  * modification, are permitted provided that the following conditions are met:
universe@34:  *
universe@34:  *   1. Redistributions of source code must retain the above copyright
universe@34:  *      notice, this list of conditions and the following disclaimer.
universe@34:  *
universe@34:  *   2. Redistributions in binary form must reproduce the above copyright
universe@34:  *      notice, this list of conditions and the following disclaimer in the
universe@34:  *      documentation and/or other materials provided with the distribution.
universe@34:  *
universe@34:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@34:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@34:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@34:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@34:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@34:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@34:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@34:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@34:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@34:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@34:  * POSSIBILITY OF SUCH DAMAGE.
universe@34:  *
universe@34:  */
universe@34: package de.uapcore.lightpit.dao;
universe@34: 
universe@34: import java.sql.SQLException;
universe@128: import java.util.List;
universe@34: 
universe@128: public interface ChildEntityDao<T, P> {
universe@128: 
universe@128:     /**
universe@128:      * Lists all entities being a child of the specified parent.
universe@128:      * @param parent the parent
universe@128:      * @return the list of child instances
universe@128:      * @throws SQLException on any kind of SQL errors
universe@128:      */
universe@128:     List<T> list(P parent) throws SQLException;
universe@38: 
universe@38:     /**
universe@47:      * Finds an entity by its integer ID.
universe@75:      * It is not guaranteed that referenced entities are automatically joined.
universe@47:      *
universe@47:      * @param id the id
universe@47:      * @return the enity or null if there is no such entity
universe@47:      * @throws SQLException on any kind of SQL errors
universe@47:      */
universe@47:     T find(int id) throws SQLException;
universe@47: 
universe@47:     /**
universe@38:      * Inserts an instance into database.
universe@75:      * It is not guaranteed that generated fields will be updated in the instance.
universe@38:      *
universe@38:      * @param instance the instance to insert
universe@128:      * @param parent a reference to the parent
universe@38:      * @throws SQLException on any kind of SQL errors
universe@38:      */
universe@128:     void save(T instance, P parent) throws SQLException;
universe@38: 
universe@38:     /**
universe@38:      * Updates an instance in the database.
universe@38:      *
universe@38:      * @param instance the instance to insert
universe@38:      * @return true if an instance has been updated, false if no instance with the specified ID was found
universe@38:      * @throws SQLException on any kind of SQL errors
universe@38:      */
universe@38:     boolean update(T instance) throws SQLException;
universe@38: 
universe@38:     /**
universe@128:      * Updates an instance in the database changing the parent.
universe@128:      * This operation is not supported by default.
universe@128:      *
universe@128:      * @param instance the instance to insert
universe@128:      * @param newParent a reference to the new parent
universe@128:      * @return true if an instance has been updated, false if no instance with the specified ID was found
universe@128:      * @throws SQLException on any kind of SQL errors
universe@128:      * @see #isChangingParentSupported()
universe@128:      */
universe@128:     default boolean update(T instance, P newParent) throws SQLException {
universe@128:         throw new UnsupportedOperationException();
universe@128:     }
universe@128: 
universe@128:     /**
universe@128:      * Returns true if changing the parent is supported by this DAO.
universe@128:      * This method must return true, if {@link #update(Object, Object)} is implemented.
universe@128:      * @return true, if changing the parent is supported
universe@128:      */
universe@128:     default boolean isChangingParentSupported() {
universe@128:         return false;
universe@128:     }
universe@128: 
universe@128:     /**
universe@38:      * Inserts or updates an instance in the database.
universe@38:      * Tries an update first and if that fails, performs a save.
universe@128:      * If changing a parent is not supported by this DAO,
universe@128:      * specifying an alternate parent for an existing instance has no effect.
universe@38:      *
universe@38:      * @param instance the instance to insert or update
universe@128:      * @param parent a reference to the parent
universe@38:      * @throws SQLException on any kind of SQL errors
universe@38:      * @see #update(Object)
universe@128:      * @see #update(Object, Object)
universe@128:      * @see #save(Object, Object)
universe@38:      */
universe@128:     default void saveOrUpdate(T instance, P parent) throws SQLException {
universe@128:         if (isChangingParentSupported()) {
universe@128:             if (!update(instance, parent)) save(instance, parent);
universe@128:         } else {
universe@128:             if (!update(instance)) save(instance, parent);
universe@128:         }
universe@38:     }
universe@34: }