1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.configuration2.interpol;
18
19 import org.apache.commons.text.lookup.StringLookupFactory;
20
21 /**
22 * Enumerates built-in {@code Lookup} objects available for
23 * {@code Configuration} instances.
24 * <p>
25 * When a new configuration object derived from {@code AbstractConfiguration} is created, it installs a
26 * {@link ConfigurationInterpolator} containing a default set of {@link Lookup} objects. These lookups are
27 * defined by this enumeration class, however not all lookups may be included in the defaults. See
28 * {@link ConfigurationInterpolator#getDefaultPrefixLookups()} for details.
29 * </p>
30 * <p>
31 * All the {@code Lookup}s defined here are state-less, thus their instances can be shared between multiple
32 * configuration objects. Therefore, it makes sense to keep shared instances in this enumeration class.
33 * </p>
34 *
35 * Provides access to lookups defined in Apache Commons Text:
36 * <ul>
37 * <li>"base64Decoder" for the {@code Base64DecoderStringLookup} since Apache Commons Text 1.6.</li>
38 * <li>"base64Encoder" for the {@code Base64EncoderStringLookup} since Apache Commons Text 1.6.</li>
39 * <li>"const" for the {@code ConstantStringLookup} since Apache Commons Text 1.5.</li>
40 * <li>"date" for the {@code DateStringLookup}.</li>
41 * <li>"env" for the {@code EnvironmentVariableStringLookup}.</li>
42 * <li>"file" for the {@code FileStringLookup} since Apache Commons Text 1.5.</li>
43 * <li>"java" for the {@code JavaPlatformStringLookup}.</li>
44 * <li>"localhost" for the {@code LocalHostStringLookup}, see {@code #localHostStringLookup()} for key names; since
45 * Apache Commons Text 1.3.</li>
46 * <li>"properties" for the {@code PropertiesStringLookup} since Apache Commons Text 1.5.</li>
47 * <li>"resourceBundle" for the {@code ResourceBundleStringLookup} since Apache Commons Text 1.5.</li>
48 * <li>"script" for the {@code ScriptStringLookup} since Apache Commons Text 1.5.</li>
49 * <li>"sys" for the {@code SystemPropertyStringLookup}.</li>
50 * <li>"url" for the {@code UrlStringLookup} since Apache Commons Text 1.5.</li>
51 * <li>"urlDecoder" for the {@code UrlDecoderStringLookup} since Apache Commons Text 1.6.</li>
52 * <li>"urlEncoder" for the {@code UrlEncoderStringLookup} since Apache Commons Text 1.6.</li>
53 * <li>"xml" for the {@code XmlStringLookup} since Apache Commons Text 1.5.</li>
54 * </ul>
55 *
56 * @since 2.0
57 */
58 public enum DefaultLookups {
59
60 /**
61 * The lookup for Base64 decoding, accessed using the prefix {@code "base64Decoder"}.
62 *
63 * @see StringLookupFactory#base64DecoderStringLookup()
64 * @since 2.4
65 */
66 BASE64_DECODER(StringLookupFactory.KEY_BASE64_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64DecoderStringLookup())),
67
68 /**
69 * The lookup for Base64 encoding, accessed using the prefix {@code "base64Encoder"}.
70 *
71 * @see StringLookupFactory#base64EncoderStringLookup()
72 * @since 2.4
73 */
74 BASE64_ENCODER(StringLookupFactory.KEY_BASE64_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64EncoderStringLookup())),
75
76 /**
77 * The lookup for Java constants, accessed using the prefix {@code "const"}.
78 *
79 * @see StringLookupFactory#constantStringLookup()
80 * @since 2.4
81 */
82 CONST(StringLookupFactory.KEY_CONST, new StringLookupAdapter(StringLookupFactory.INSTANCE.constantStringLookup())),
83
84 /**
85 * The lookup for the current date in a specified format, accessed using the prefix {@code "date"}.
86 *
87 * @see StringLookupFactory#dateStringLookup()
88 * @since 2.4
89 */
90 DATE(StringLookupFactory.KEY_DATE, new StringLookupAdapter(StringLookupFactory.INSTANCE.dateStringLookup())),
91
92 /**
93 * The lookup for DNS, accessed using the prefix {@code "dns"}.
94 *
95 * @see StringLookupFactory#dnsStringLookup()
96 * @since 2.6
97 */
98 DNS(StringLookupFactory.KEY_DNS, new StringLookupAdapter(StringLookupFactory.INSTANCE.dnsStringLookup())),
99
100 /**
101 * The lookup for environment properties, accessed using the prefix {@code "env"}.
102 *
103 * @see StringLookupFactory#environmentVariableStringLookup()
104 */
105 ENVIRONMENT(StringLookupFactory.KEY_ENV, new StringLookupAdapter(StringLookupFactory.INSTANCE.environmentVariableStringLookup())),
106
107 /**
108 * The lookup for file content, accessed using the prefix {@code "file"}.
109 *
110 * @see StringLookupFactory#fileStringLookup()
111 * @since 2.4
112 */
113 FILE(StringLookupFactory.KEY_FILE, new StringLookupAdapter(StringLookupFactory.INSTANCE.fileStringLookup())),
114
115 /**
116 * The lookup for Java platform information, accessed using the prefix {@code "java"}.
117 *
118 * @see StringLookupFactory#javaPlatformStringLookup()
119 * @since 2.4
120 */
121 JAVA(StringLookupFactory.KEY_JAVA, new StringLookupAdapter(StringLookupFactory.INSTANCE.javaPlatformStringLookup())),
122
123 /**
124 * The lookup for localhost information, accessed using the prefix {@code "localhost"}.
125 *
126 * @see StringLookupFactory#localHostStringLookup()
127 * @since 2.4
128 */
129 LOCAL_HOST(StringLookupFactory.KEY_LOCALHOST, new StringLookupAdapter(StringLookupFactory.INSTANCE.localHostStringLookup())),
130
131 /**
132 * The lookup for properties, accessed using the prefix {@code "properties"}.
133 *
134 * @see StringLookupFactory#propertiesStringLookup()
135 * @since 2.4
136 */
137 PROPERTIES(StringLookupFactory.KEY_PROPERTIES, new StringLookupAdapter(StringLookupFactory.INSTANCE.propertiesStringLookup())),
138
139 /**
140 * The lookup for resource bundles, accessed using the prefix {@code "resourceBundle"}.
141 *
142 * @see StringLookupFactory#resourceBundleStringLookup()
143 * @since 2.4
144 */
145 RESOURCE_BUNDLE(StringLookupFactory.KEY_RESOURCE_BUNDLE, new StringLookupAdapter(StringLookupFactory.INSTANCE.resourceBundleStringLookup())),
146
147 /**
148 * The lookup for scripts, accessed using the prefix {@code "script"}.
149 *
150 * @see StringLookupFactory#scriptStringLookup()
151 * @since 2.4
152 */
153 SCRIPT(StringLookupFactory.KEY_SCRIPT, new StringLookupAdapter(StringLookupFactory.INSTANCE.scriptStringLookup())),
154
155 /**
156 * The lookup for system properties, accessed using the prefix {@code "sys"}.
157 *
158 * @see StringLookupFactory#systemPropertyStringLookup()
159 */
160 SYSTEM_PROPERTIES(StringLookupFactory.KEY_SYS, new StringLookupAdapter(StringLookupFactory.INSTANCE.systemPropertyStringLookup())),
161
162 /**
163 * The lookup for URLs, accessed using the prefix {@code "url"}.
164 *
165 * @see StringLookupFactory#urlStringLookup()
166 * @since 2.4
167 */
168 URL(StringLookupFactory.KEY_URL, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlStringLookup())),
169
170 /**
171 * The lookup for URL decoding, accessed using the prefix {@code "urlDecoder"}.
172 *
173 * @see StringLookupFactory#urlDecoderStringLookup()
174 * @since 2.4
175 */
176 URL_DECODER(StringLookupFactory.KEY_URL_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlDecoderStringLookup())),
177
178 /**
179 * The lookup for URL encoding, accessed using the prefix {@code "urlEncoder"}.
180 *
181 * @see StringLookupFactory#urlEncoderStringLookup()
182 * @since 2.4
183 */
184 URL_ENCODER(StringLookupFactory.KEY_URL_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlEncoderStringLookup())),
185
186 /**
187 * The lookup for XML content, accessed using the prefix {@code "xml"}.
188 *
189 * @see StringLookupFactory#xmlStringLookup()
190 * @since 2.4
191 */
192 XML(StringLookupFactory.KEY_XML, new StringLookupAdapter(StringLookupFactory.INSTANCE.xmlStringLookup()));
193
194 /** The associated lookup instance. */
195 private final Lookup lookup;
196
197 /** The prefix under which the associated lookup object is registered. */
198 private final String prefix;
199
200 /**
201 * Creates a new instance of {@code DefaultLookups} and sets the prefix and the associated lookup instance.
202 *
203 * @param prefix the prefix
204 * @param lookup the {@code Lookup} instance
205 */
206 DefaultLookups(final String prefix, final Lookup lookup) {
207 this.prefix = prefix;
208 this.lookup = lookup;
209 }
210
211 /**
212 * Gets the standard {@code Lookup} instance of this kind.
213 *
214 * @return the associated {@code Lookup} object
215 */
216 public Lookup getLookup() {
217 return lookup;
218 }
219
220 /**
221 * Gets the standard prefix for the lookup object of this kind.
222 *
223 * @return the prefix
224 */
225 public String getPrefix() {
226 return prefix;
227 }
228 }