comparison: src/main/java/de/uapcore/lightpit/dao/ChildEntityDao.java
src/main/java/de/uapcore/lightpit/dao/ChildEntityDao.java
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- 86b5d8a1662f
- parent 128
- 947d0f6a6a83
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| 158:4f912cd42876 | 159:86b5d8a1662f |
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| 1 /* | |
| 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. | |
| 3 * | |
| 4 * Copyright 2018 Mike Becker. All rights reserved. | |
| 5 * | |
| 6 * Redistribution and use in source and binary forms, with or without | |
| 7 * modification, are permitted provided that the following conditions are met: | |
| 8 * | |
| 9 * 1. Redistributions of source code must retain the above copyright | |
| 10 * notice, this list of conditions and the following disclaimer. | |
| 11 * | |
| 12 * 2. Redistributions in binary form must reproduce the above copyright | |
| 13 * notice, this list of conditions and the following disclaimer in the | |
| 14 * documentation and/or other materials provided with the distribution. | |
| 15 * | |
| 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE | |
| 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 26 * POSSIBILITY OF SUCH DAMAGE. | |
| 27 * | |
| 28 */ | |
| 29 package de.uapcore.lightpit.dao; | |
| 30 | |
| 31 import java.sql.SQLException; | |
| 32 import java.util.List; | |
| 33 | |
| 34 public interface ChildEntityDao<T, P> { | |
| 35 | |
| 36 /** | |
| 37 * Lists all entities being a child of the specified parent. | |
| 38 * @param parent the parent | |
| 39 * @return the list of child instances | |
| 40 * @throws SQLException on any kind of SQL errors | |
| 41 */ | |
| 42 List<T> list(P parent) throws SQLException; | |
| 43 | |
| 44 /** | |
| 45 * Finds an entity by its integer ID. | |
| 46 * It is not guaranteed that referenced entities are automatically joined. | |
| 47 * | |
| 48 * @param id the id | |
| 49 * @return the enity or null if there is no such entity | |
| 50 * @throws SQLException on any kind of SQL errors | |
| 51 */ | |
| 52 T find(int id) throws SQLException; | |
| 53 | |
| 54 /** | |
| 55 * Inserts an instance into database. | |
| 56 * It is not guaranteed that generated fields will be updated in the instance. | |
| 57 * | |
| 58 * @param instance the instance to insert | |
| 59 * @param parent a reference to the parent | |
| 60 * @throws SQLException on any kind of SQL errors | |
| 61 */ | |
| 62 void save(T instance, P parent) throws SQLException; | |
| 63 | |
| 64 /** | |
| 65 * Updates an instance in the database. | |
| 66 * | |
| 67 * @param instance the instance to insert | |
| 68 * @return true if an instance has been updated, false if no instance with the specified ID was found | |
| 69 * @throws SQLException on any kind of SQL errors | |
| 70 */ | |
| 71 boolean update(T instance) throws SQLException; | |
| 72 | |
| 73 /** | |
| 74 * Updates an instance in the database changing the parent. | |
| 75 * This operation is not supported by default. | |
| 76 * | |
| 77 * @param instance the instance to insert | |
| 78 * @param newParent a reference to the new parent | |
| 79 * @return true if an instance has been updated, false if no instance with the specified ID was found | |
| 80 * @throws SQLException on any kind of SQL errors | |
| 81 * @see #isChangingParentSupported() | |
| 82 */ | |
| 83 default boolean update(T instance, P newParent) throws SQLException { | |
| 84 throw new UnsupportedOperationException(); | |
| 85 } | |
| 86 | |
| 87 /** | |
| 88 * Returns true if changing the parent is supported by this DAO. | |
| 89 * This method must return true, if {@link #update(Object, Object)} is implemented. | |
| 90 * @return true, if changing the parent is supported | |
| 91 */ | |
| 92 default boolean isChangingParentSupported() { | |
| 93 return false; | |
| 94 } | |
| 95 | |
| 96 /** | |
| 97 * Inserts or updates an instance in the database. | |
| 98 * Tries an update first and if that fails, performs a save. | |
| 99 * If changing a parent is not supported by this DAO, | |
| 100 * specifying an alternate parent for an existing instance has no effect. | |
| 101 * | |
| 102 * @param instance the instance to insert or update | |
| 103 * @param parent a reference to the parent | |
| 104 * @throws SQLException on any kind of SQL errors | |
| 105 * @see #update(Object) | |
| 106 * @see #update(Object, Object) | |
| 107 * @see #save(Object, Object) | |
| 108 */ | |
| 109 default void saveOrUpdate(T instance, P parent) throws SQLException { | |
| 110 if (isChangingParentSupported()) { | |
| 111 if (!update(instance, parent)) save(instance, parent); | |
| 112 } else { | |
| 113 if (!update(instance)) save(instance, parent); | |
| 114 } | |
| 115 } | |
| 116 } |
