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 } |
|