1 /*
2 * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.properties.api.core.app;
17
18 import javax.naming.Context;
19 import javax.naming.NameAlreadyBoundException;
20 import javax.naming.NameClassPair;
21 import javax.naming.NameNotFoundException;
22 import javax.naming.NamingEnumeration;
23 import javax.naming.NamingException;
24
25 import org.apache.commons.lang.ObjectUtils;
26 import org.apache.commons.lang.StringUtils;
27
28 /**
29 * Defines constants for this library.
30 */
31 public final class JndiContext
32 {
33 // ********************************* Fields *********************************
34
35 // --- constants ------------------------------------------------------------
36
37 /**
38 * The path within the JNDI context that provides information for
39 * smartics-properties.
40 */
41 private static final String JNDI_CONTEXT_PATH = "/smartics-properties";
42
43 /**
44 * The path within the JNDI context to access boot configuration properties.
45 */
46 public static final String JNDI_CONTEXT_PATH_BOOT = JNDI_CONTEXT_PATH
47 + "/boot";
48
49 /**
50 * The path within the JNDI context to access boot configuration properties.
51 */
52 private static final String JNDI_CONTEXT_PATH_CONFIG = JNDI_CONTEXT_PATH
53 + "/config";
54
55 // --- members --------------------------------------------------------------
56
57 /**
58 * The context to lookup the values.
59 */
60 private final Context context;
61
62 /**
63 * A path within the context to set the root of the configuration. May be
64 * <code>null</code> in which case the context is itself the root. The subpath
65 * is required to start with a slash ( <code>/</code>), but may be
66 * <code>null</code>. If it contains only whitespaces, the subpath is assumed
67 * to be <code>null</code>.
68 */
69 private final String path;
70
71 // ****************************** Initializer *******************************
72
73 // ****************************** Constructors ******************************
74
75 /**
76 * Default constructor.
77 *
78 * @param context the context to lookup the values.
79 * @param subpath a path within the context to set the root of the
80 * configuration. The subpath is required to start with a slash (
81 * <code>/</code>), but may be <code>null</code>. If it contains only
82 * whitespaces, the subpath is assumed to be <code>null</code>.
83 * @param configKey the configuration key which to be the last element of the
84 * subpath. The key is normalized so that all slashes are replaced by
85 * pipes.
86 * @throws IllegalArgumentException if the JNDI context cannot be initialized.
87 */
88 private JndiContext(final Context context, final String subpath,
89 final String configKey) throws IllegalArgumentException
90 {
91 this.context = context;
92 this.path = calcPath(subpath, configKey);
93
94 initialize();
95 }
96
97 // ****************************** Inner Classes *****************************
98
99 // ********************************* Methods ********************************
100
101 // --- init -----------------------------------------------------------------
102
103 private static String calcPath(final String path, final String configKey)
104 {
105 return path + normalizeKey(configKey);
106 }
107
108 private static String normalizeKey(final String configKey)
109 {
110 if (StringUtils.isBlank(configKey))
111 {
112 return "";
113 }
114
115 return '/' + configKey.replace('/', '|');
116 }
117
118 // --- factory --------------------------------------------------------------
119
120 /**
121 * Provides access to the boot properties within a JNDI context.
122 *
123 * @param context the root context.
124 * @return the JNDI context for boot properties.
125 * @throws IllegalArgumentException if the JNDI context cannot be initialized.
126 */
127 public static JndiContext boot(final Context context)
128 throws IllegalArgumentException
129 {
130 return new JndiContext(context, JNDI_CONTEXT_PATH_BOOT, null);
131 }
132
133 /**
134 * Provides access to the custom properties within a JNDI context.
135 *
136 * @param context the custom context.
137 * @param configKey the key to the configuration. Will be used as a path
138 * within the context to set the root of the configuration.
139 * @return the JNDI context for custom properties.
140 * @throws IllegalArgumentException if the JNDI context cannot be initialized.
141 */
142 public static JndiContext config(final Context context, final String configKey)
143 throws IllegalArgumentException
144 {
145 return new JndiContext(context, JNDI_CONTEXT_PATH_CONFIG, configKey);
146 }
147
148 // --- get&set --------------------------------------------------------------
149
150 // --- business -------------------------------------------------------------
151
152 /**
153 * Initialized the context.
154 *
155 * @throws NamingException on any problem encountered.
156 */
157 private void initialize() throws IllegalArgumentException
158 {
159 final String path = this.path.substring(1);
160 try
161 {
162 context.createSubcontext(path);
163 }
164 catch (final NameAlreadyBoundException e)
165 {
166 // OK, the context has already been established.
167 }
168 catch (final NamingException e)
169 {
170 throw new IllegalArgumentException("Cannot create subcontext for '"
171 + path + "'.", e);
172 }
173 }
174
175 /**
176 * Runs a lookup for the value with the given {@code key} in the JNDI context.
177 *
178 * @param key the key to the value.
179 * @return the value to the key in the context.
180 * @throws NamingException on any problem accessing the value.
181 */
182 public Object lookupObject(final String key) throws NamingException
183 {
184 try
185 {
186 final String jndiKey = createJndiKey(key);
187 final Object value = context.lookup(jndiKey);
188 return value;
189 }
190 catch (final NameNotFoundException e)
191 {
192 return null;
193 }
194
195 }
196
197 private String createJndiKey(final String key)
198 {
199 final String normalized = key.replace('.', '/');
200 return path + '/' + normalized;
201 }
202
203 /**
204 * Runs a lookup for the value with the given {@code key} in the JNDI context
205 * and returns the value as a {@link String}.
206 *
207 * @param key the key to the value.
208 * @return the value to the key in the context.
209 * @throws NamingException on any problem accessing the value.
210 */
211 public String lookup(final String key) throws NamingException
212 {
213 try
214 {
215 final String value = ObjectUtils.toString(lookupObject(key), null);
216 return value;
217 }
218 catch (final NameNotFoundException e)
219 {
220 return null;
221 }
222 }
223
224 /**
225 * Runs a lookup for the value with the given {@code key} in the JNDI context.
226 *
227 * @param key the key to the value.
228 * @return the value to the key in the context.
229 * @throws NamingException on any problem accessing the value.
230 */
231 public Boolean lookupBoolean(final String key) throws NamingException
232 {
233 final Object value = lookupObject(key);
234
235 if (value instanceof Boolean)
236 {
237 return (Boolean) value;
238 }
239
240 final Boolean booleanValue =
241 Boolean.valueOf(ObjectUtils.toString(value, null));
242 return booleanValue;
243 }
244
245 /**
246 * Sets the value for the given {@code key}.
247 *
248 * @param key the key to the value.
249 * @param value the value to the key in the context.
250 * @throws NamingException on any problem accessing the value.
251 */
252 public void set(final String key, final Object value) throws NamingException
253 {
254 final String jndiKey = createJndiKey(key);
255 if (value != null)
256 {
257 context.rebind(jndiKey, value);
258 }
259 else
260 {
261 try
262 {
263 if (context.lookup(jndiKey) != null)
264 {
265 context.unbind(jndiKey);
266 }
267 }
268 catch (final NameNotFoundException e)
269 {
270 // OK, not existing.
271 }
272 }
273 }
274
275 /**
276 * Returns the list of stored values in the context.
277 *
278 * @return the list of stored values in the context.
279 * @throws NamingException on any problem accessing the naming context.
280 */
281 public NamingEnumeration<NameClassPair> list() throws NamingException
282 {
283 return context.list(path);
284 }
285
286 /**
287 * Returns the name of the JNDI namespace.
288 *
289 * @return the name of the JNDI namespace.
290 */
291 public String getSourceId()
292 {
293 return "java:" + path;
294 }
295
296 // --- object basics --------------------------------------------------------
297
298 }