1 /*
2 * #%L
3 * settings4j
4 * ===============================================================
5 * Copyright (C) 2008 - 2015 Brabenetz Harald, Austria
6 * ===============================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package org.settings4j;
21
22 import org.settings4j.settings.position.ConnectorPositionAfterFirstClass;
23 import org.settings4j.settings.position.ConnectorPositionAfterLastClass;
24 import org.settings4j.settings.position.ConnectorPositionAfterName;
25 import org.settings4j.settings.position.ConnectorPositionAtFirst;
26 import org.settings4j.settings.position.ConnectorPositionAtLast;
27 import org.settings4j.settings.position.ConnectorPositionBeforeFirstClass;
28 import org.settings4j.settings.position.ConnectorPositionBeforeLastClass;
29 import org.settings4j.settings.position.ConnectorPositionBeforeName;
30 import org.settings4j.settings.position.ConnectorPositionFirstValid;
31
32
33 /**
34 * ConnectorPostitions used for {@link Settings4jInstance#addConnector(Connector, ConnectorPosition)}.
35 * <h3>Exampe Usage:</h3>
36 *
37 * <pre>
38 * --------------------------------------
39 * Connector myConnector = ...
40 * if (Settings4j.getSettings().getConnector(myConnector.getName()) == null) {
41 * Settings4j.getSettings().addConnector(myConnector, ConnectorPositions.firstValid(//
42 * ConnectorPositions.afterLast(SystemPropertyConnector.class),
43 * ConnectorPositions.atFirst() // fallback if no SystemPropertyConnector exists.
44 * )
45 * );
46 * }
47 * --------------------------------------
48 * </pre>
49 * <p>
50 * It is even more readable with static import:
51 * </p>
52 *
53 * <pre>
54 * --------------------------------------
55 * import static org.settings4j.ConnectorPositions.*;
56 * ..
57 * Connector myConnector = ...
58 * if (Settings4j.getSettings().getConnector(myConnector.getName()) == null) {
59 * Settings4j.getSettings().addConnector(myConnector, //
60 * firstValid(afterLast(SystemPropertyConnector.class), atFirst())
61 * );
62 * }
63 * --------------------------------------
64 * </pre>
65 *
66 * @author brabenetz
67 */
68 public final class ConnectorPositions {
69
70 /** Hide constructor (Utility Pattern). */
71 private ConnectorPositions() {
72 super();
73 }
74
75 /**
76 * @param connectorName The {@link Connector#getName()} to search for.
77 * @return {@link ConnectorPositionBeforeName}
78 */
79 public static ConnectorPosition before(final String connectorName) {
80 return new ConnectorPositionBeforeName(connectorName);
81 }
82
83 /**
84 * @param connectorClass the connector class to search in the given connectors list.
85 * @return {@link ConnectorPositionBeforeFirstClass}
86 */
87 public static ConnectorPosition beforeFirst(final Class<? extends Connector> connectorClass) {
88 return new ConnectorPositionBeforeFirstClass(connectorClass);
89 }
90
91 /**
92 * @param connectorClass the connector class to search in the given connectors list.
93 * @return {@link ConnectorPositionBeforeLastClass}
94 */
95 public static ConnectorPosition beforeLast(final Class<? extends Connector> connectorClass) {
96 return new ConnectorPositionBeforeLastClass(connectorClass);
97 }
98
99 /**
100 * @param connectorName The {@link Connector#getName()} to search for.
101 * @return {@link ConnectorPositionAfterName}
102 */
103 public static ConnectorPosition after(final String connectorName) {
104 return new ConnectorPositionAfterName(connectorName);
105 }
106
107 /**
108 * @param connectorClass the connector class to search in the given connectors list.
109 * @return {@link ConnectorPositionAfterFirstClass}
110 */
111 public static ConnectorPosition afterFirst(final Class<? extends Connector> connectorClass) {
112 return new ConnectorPositionAfterFirstClass(connectorClass);
113 }
114
115 /**
116 * @param connectorClass the connector class to search in the given connectors list.
117 * @return {@link ConnectorPositionAfterLastClass}
118 */
119 public static ConnectorPosition afterLast(final Class<? extends Connector> connectorClass) {
120 return new ConnectorPositionAfterLastClass(connectorClass);
121 }
122
123 /**
124 * @return {@link ConnectorPositionAtFirst} which always returns an valid position.
125 */
126 public static ConnectorPosition atFirst() {
127 return new ConnectorPositionAtFirst();
128 }
129
130 /**
131 * @return {@link ConnectorPositionAtLast} which always returns an valid position.
132 */
133 public static ConnectorPosition atLast() {
134 return new ConnectorPositionAtLast();
135 }
136
137 /**
138 * @param connectorPosition the {@link ConnectorPosition}s to search for a valid position.
139 * @return ConnectorPositionFirstValid
140 */
141 public static ConnectorPosition firstValid(final ConnectorPosition... connectorPosition) {
142 return new ConnectorPositionFirstValid(connectorPosition);
143 }
144 }