Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
CombinedConfiguration |
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| 2.1951219512195124;2,195 | ||||
CombinedConfiguration$ConfigData |
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| 2.1951219512195124;2,195 |
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 | * http://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.configuration; | |
18 | ||
19 | import java.io.ByteArrayOutputStream; | |
20 | import java.io.PrintStream; | |
21 | import java.util.ArrayList; | |
22 | import java.util.Collection; | |
23 | import java.util.HashMap; | |
24 | import java.util.Iterator; | |
25 | import java.util.List; | |
26 | import java.util.Map; | |
27 | import java.util.Set; | |
28 | ||
29 | import org.apache.commons.configuration.event.ConfigurationEvent; | |
30 | import org.apache.commons.configuration.event.ConfigurationListener; | |
31 | import org.apache.commons.configuration.tree.ConfigurationNode; | |
32 | import org.apache.commons.configuration.tree.DefaultConfigurationKey; | |
33 | import org.apache.commons.configuration.tree.DefaultConfigurationNode; | |
34 | import org.apache.commons.configuration.tree.DefaultExpressionEngine; | |
35 | import org.apache.commons.configuration.tree.ExpressionEngine; | |
36 | import org.apache.commons.configuration.tree.NodeCombiner; | |
37 | import org.apache.commons.configuration.tree.TreeUtils; | |
38 | import org.apache.commons.configuration.tree.UnionCombiner; | |
39 | import org.apache.commons.configuration.tree.ViewNode; | |
40 | ||
41 | /** | |
42 | * <p> | |
43 | * A hierarchical composite configuration class. | |
44 | * </p> | |
45 | * <p> | |
46 | * This class maintains a list of configuration objects, which can be added | |
47 | * using the divers {@code addConfiguration()} methods. After that the | |
48 | * configurations can be accessed either by name (if one was provided when the | |
49 | * configuration was added) or by index. For the whole set of managed | |
50 | * configurations a logical node structure is constructed. For this purpose a | |
51 | * {@link org.apache.commons.configuration.tree.NodeCombiner NodeCombiner} | |
52 | * object can be set. This makes it possible to specify different algorithms for | |
53 | * the combination process. | |
54 | * </p> | |
55 | * <p> | |
56 | * The big advantage of this class is that it creates a truly hierarchical | |
57 | * structure of all the properties stored in the contained configurations - even | |
58 | * if some of them are no hierarchical configurations per se. So all enhanced | |
59 | * features provided by a hierarchical configuration (e.g. choosing an | |
60 | * expression engine) are applicable. | |
61 | * </p> | |
62 | * <p> | |
63 | * The class works by registering itself as an event listener at all added | |
64 | * configurations. So it gets notified whenever one of these configurations is | |
65 | * changed and can invalidate its internal node structure. The next time a | |
66 | * property is accessed the node structure will be re-constructed using the | |
67 | * current state of the managed configurations. Note that, depending on the used | |
68 | * {@code NodeCombiner}, this may be a complex operation. | |
69 | * </p> | |
70 | * <p> | |
71 | * Because of the way a {@code CombinedConfiguration} is working it has | |
72 | * more or less view character: it provides a logic view on the configurations | |
73 | * it contains. In this constellation not all methods defined for hierarchical | |
74 | * configurations - especially methods that update the stored properties - can | |
75 | * be implemented in a consistent manner. Using such methods (like | |
76 | * {@code addProperty()}, or {@code clearProperty()} on a | |
77 | * {@code CombinedConfiguration} is not strictly forbidden, however, | |
78 | * depending on the current {@link NodeCombiner} and the involved | |
79 | * properties, the results may be different than expected. Some examples may | |
80 | * illustrate this: | |
81 | * </p> | |
82 | * <p> | |
83 | * <ul> | |
84 | * <li>Imagine a {@code CombinedConfiguration} <em>cc</em> containing | |
85 | * two child configurations with the following content: | |
86 | * <dl> | |
87 | * <dt>user.properties</dt> | |
88 | * <dd> | |
89 | * | |
90 | * <pre> | |
91 | * gui.background = blue | |
92 | * gui.position = (10, 10, 400, 200) | |
93 | * </pre> | |
94 | * | |
95 | * </dd> | |
96 | * <dt>default.properties</dt> | |
97 | * <dd> | |
98 | * | |
99 | * <pre> | |
100 | * gui.background = black | |
101 | * gui.foreground = white | |
102 | * home.dir = /data | |
103 | * </pre> | |
104 | * | |
105 | * </dd> | |
106 | * </dl> | |
107 | * As a {@code NodeCombiner} a | |
108 | * {@link org.apache.commons.configuration.tree.OverrideCombiner OverrideCombiner} | |
109 | * is used. This combiner will ensure that defined user settings take precedence | |
110 | * over the default values. If the resulting {@code CombinedConfiguration} | |
111 | * is queried for the background color, {@code blue} will be returned | |
112 | * because this value is defined in {@code user.properties}. Now | |
113 | * consider what happens if the key {@code gui.background} is removed | |
114 | * from the {@code CombinedConfiguration}: | |
115 | * | |
116 | * <pre>cc.clearProperty("gui.background");</pre> | |
117 | * | |
118 | * Will a {@code cc.containsKey("gui.background")} now return <b>false</b>? | |
119 | * No, it won't! The {@code clearProperty()} operation is executed on the | |
120 | * node set of the combined configuration, which was constructed from the nodes | |
121 | * of the two child configurations. It causes the value of the | |
122 | * <em>background</em> node to be cleared, which is also part of the first | |
123 | * child configuration. This modification of one of its child configurations | |
124 | * causes the {@code CombinedConfiguration} to be re-constructed. This | |
125 | * time the {@code OverrideCombiner} cannot find a | |
126 | * {@code gui.background} property in the first child configuration, but | |
127 | * it finds one in the second, and adds it to the resulting combined | |
128 | * configuration. So the property is still present (with a different value now).</li> | |
129 | * <li>{@code addProperty()} can also be problematic: Most node | |
130 | * combiners use special view nodes for linking parts of the original | |
131 | * configurations' data together. If new properties are added to such a special | |
132 | * node, they do not belong to any of the managed configurations and thus hang | |
133 | * in the air. Using the same configurations as in the last example, the | |
134 | * statement | |
135 | * | |
136 | * <pre> | |
137 | * addProperty("database.user", "scott"); | |
138 | * </pre> | |
139 | * | |
140 | * would cause such a hanging property. If now one of the child configurations | |
141 | * is changed and the {@code CombinedConfiguration} is re-constructed, | |
142 | * this property will disappear! (Add operations are not problematic if they | |
143 | * result in a child configuration being updated. For instance an | |
144 | * {@code addProperty("home.url", "localhost");} will alter the second | |
145 | * child configuration - because the prefix <em>home</em> is here already | |
146 | * present; when the {@code CombinedConfiguration} is re-constructed, | |
147 | * this change is taken into account.)</li> | |
148 | * </ul> | |
149 | * Because of such problems it is recommended to perform updates only on the | |
150 | * managed child configurations. | |
151 | * </p> | |
152 | * <p> | |
153 | * Whenever the node structure of a {@code CombinedConfiguration} becomes | |
154 | * invalid (either because one of the contained configurations was modified or | |
155 | * because the {@code invalidate()} method was directly called) an event | |
156 | * is generated. So this can be detected by interested event listeners. This | |
157 | * also makes it possible to add a combined configuration into another one. | |
158 | * </p> | |
159 | * <p> | |
160 | * Implementation note: Adding and removing configurations to and from a | |
161 | * combined configuration is not thread-safe. If a combined configuration is | |
162 | * manipulated by multiple threads, the developer has to take care about | |
163 | * properly synchronization. | |
164 | * </p> | |
165 | * | |
166 | * @author <a | |
167 | * href="http://commons.apache.org/configuration/team-list.html">Commons | |
168 | * Configuration team</a> | |
169 | * @since 1.3 | |
170 | * @version $Id: CombinedConfiguration.java 1234985 2012-01-23 21:09:09Z oheger $ | |
171 | */ | |
172 | 20 | public class CombinedConfiguration extends HierarchicalReloadableConfiguration implements |
173 | ConfigurationListener, Cloneable | |
174 | { | |
175 | /** | |
176 | * Constant for the invalidate event that is fired when the internal node | |
177 | * structure becomes invalid. | |
178 | */ | |
179 | public static final int EVENT_COMBINED_INVALIDATE = 40; | |
180 | ||
181 | /** | |
182 | * The serial version ID. | |
183 | */ | |
184 | private static final long serialVersionUID = 8338574525528692307L; | |
185 | ||
186 | /** Constant for the expression engine for parsing the at path. */ | |
187 | 1 | private static final DefaultExpressionEngine AT_ENGINE = new DefaultExpressionEngine(); |
188 | ||
189 | /** Constant for the default node combiner. */ | |
190 | 1 | private static final NodeCombiner DEFAULT_COMBINER = new UnionCombiner(); |
191 | ||
192 | /** Constant for the name of the property used for the reload check.*/ | |
193 | private static final String PROP_RELOAD_CHECK = "CombinedConfigurationReloadCheck"; | |
194 | ||
195 | /** Stores the combiner. */ | |
196 | private NodeCombiner nodeCombiner; | |
197 | ||
198 | /** Stores the combined root node. */ | |
199 | private volatile ConfigurationNode combinedRoot; | |
200 | ||
201 | /** Stores a list with the contained configurations. */ | |
202 | private List<ConfigData> configurations; | |
203 | ||
204 | /** Stores a map with the named configurations. */ | |
205 | private Map<String, AbstractConfiguration> namedConfigurations; | |
206 | ||
207 | /** The default behavior is to ignore exceptions that occur during reload */ | |
208 | 222 | private boolean ignoreReloadExceptions = true; |
209 | ||
210 | /** Set to true when the backing file has changed */ | |
211 | private boolean reloadRequired; | |
212 | ||
213 | /** | |
214 | * An expression engine used for converting child configurations to | |
215 | * hierarchical ones. | |
216 | */ | |
217 | private ExpressionEngine conversionExpressionEngine; | |
218 | ||
219 | /** A flag whether an enhanced reload check is to be performed.*/ | |
220 | private boolean forceReloadCheck; | |
221 | ||
222 | /** | |
223 | * Creates a new instance of {@code CombinedConfiguration} and | |
224 | * initializes the combiner to be used. | |
225 | * | |
226 | * @param comb the node combiner (can be <b>null</b>, then a union combiner | |
227 | * is used as default) | |
228 | */ | |
229 | public CombinedConfiguration(NodeCombiner comb) | |
230 | 87 | { |
231 | 87 | setNodeCombiner((comb != null) ? comb : DEFAULT_COMBINER); |
232 | 87 | clear(); |
233 | 87 | } |
234 | ||
235 | public CombinedConfiguration(NodeCombiner comb, Lock lock) | |
236 | { | |
237 | 135 | super(lock); |
238 | 135 | setNodeCombiner((comb != null) ? comb : DEFAULT_COMBINER); |
239 | 135 | clear(); |
240 | 135 | } |
241 | ||
242 | public CombinedConfiguration(Lock lock) | |
243 | { | |
244 | 0 | this(null, lock); |
245 | 0 | } |
246 | ||
247 | /** | |
248 | * Creates a new instance of {@code CombinedConfiguration} that uses | |
249 | * a union combiner. | |
250 | * | |
251 | * @see org.apache.commons.configuration.tree.UnionCombiner | |
252 | */ | |
253 | public CombinedConfiguration() | |
254 | { | |
255 | 135 | this(null, null); |
256 | 135 | } |
257 | ||
258 | /** | |
259 | * Returns the node combiner that is used for creating the combined node | |
260 | * structure. | |
261 | * | |
262 | * @return the node combiner | |
263 | */ | |
264 | public NodeCombiner getNodeCombiner() | |
265 | { | |
266 | 2191 | return nodeCombiner; |
267 | } | |
268 | ||
269 | /** | |
270 | * Sets the node combiner. This object will be used when the combined node | |
271 | * structure is to be constructed. It must not be <b>null</b>, otherwise an | |
272 | * {@code IllegalArgumentException} exception is thrown. Changing the | |
273 | * node combiner causes an invalidation of this combined configuration, so | |
274 | * that the new combiner immediately takes effect. | |
275 | * | |
276 | * @param nodeCombiner the node combiner | |
277 | */ | |
278 | public void setNodeCombiner(NodeCombiner nodeCombiner) | |
279 | { | |
280 | 260 | if (nodeCombiner == null) |
281 | { | |
282 | 1 | throw new IllegalArgumentException( |
283 | "Node combiner must not be null!"); | |
284 | } | |
285 | 259 | this.nodeCombiner = nodeCombiner; |
286 | 259 | invalidate(); |
287 | 259 | } |
288 | ||
289 | /** | |
290 | * Returns a flag whether an enhanced reload check must be performed. | |
291 | * | |
292 | * @return the force reload check flag | |
293 | * @since 1.4 | |
294 | */ | |
295 | public boolean isForceReloadCheck() | |
296 | { | |
297 | 44633 | return forceReloadCheck; |
298 | } | |
299 | ||
300 | /** | |
301 | * Sets the force reload check flag. If this flag is set, each property | |
302 | * access on this configuration will cause a reload check on the contained | |
303 | * configurations. This is a workaround for a problem with some reload | |
304 | * implementations that only check if a reload is required when they are | |
305 | * triggered. Per default this mode is disabled. If the force reload check | |
306 | * flag is set to <b>true</b>, accessing properties will be less | |
307 | * efficient, but reloads on contained configurations will be detected. | |
308 | * | |
309 | * @param forceReloadCheck the value of the flag | |
310 | * @since 1.4 | |
311 | */ | |
312 | public void setForceReloadCheck(boolean forceReloadCheck) | |
313 | { | |
314 | 129 | this.forceReloadCheck = forceReloadCheck; |
315 | 129 | } |
316 | ||
317 | /** | |
318 | * Returns the {@code ExpressionEngine} for converting flat child | |
319 | * configurations to hierarchical ones. | |
320 | * | |
321 | * @return the conversion expression engine | |
322 | * @since 1.6 | |
323 | */ | |
324 | public ExpressionEngine getConversionExpressionEngine() | |
325 | { | |
326 | 4331 | return conversionExpressionEngine; |
327 | } | |
328 | ||
329 | /** | |
330 | * Sets the {@code ExpressionEngine} for converting flat child | |
331 | * configurations to hierarchical ones. When constructing the root node for | |
332 | * this combined configuration the properties of all child configurations | |
333 | * must be combined to a single hierarchical node structure. In this | |
334 | * process, non hierarchical configurations are converted to hierarchical | |
335 | * ones first. This can be problematic if a child configuration contains | |
336 | * keys that are no compatible with the default expression engine used by | |
337 | * hierarchical configurations. Therefore it is possible to specify a | |
338 | * specific expression engine to be used for this purpose. | |
339 | * | |
340 | * @param conversionExpressionEngine the conversion expression engine | |
341 | * @see ConfigurationUtils#convertToHierarchical(Configuration, ExpressionEngine) | |
342 | * @since 1.6 | |
343 | */ | |
344 | public void setConversionExpressionEngine( | |
345 | ExpressionEngine conversionExpressionEngine) | |
346 | { | |
347 | 64 | this.conversionExpressionEngine = conversionExpressionEngine; |
348 | 64 | } |
349 | ||
350 | /** | |
351 | * Retrieves the value of the ignoreReloadExceptions flag. | |
352 | * @return true if exceptions are ignored, false otherwise. | |
353 | */ | |
354 | public boolean isIgnoreReloadExceptions() | |
355 | { | |
356 | 89 | return ignoreReloadExceptions; |
357 | } | |
358 | ||
359 | /** | |
360 | * If set to true then exceptions that occur during reloading will be | |
361 | * ignored. If false then the exceptions will be allowed to be thrown | |
362 | * back to the caller. | |
363 | * @param ignoreReloadExceptions true if exceptions should be ignored. | |
364 | */ | |
365 | public void setIgnoreReloadExceptions(boolean ignoreReloadExceptions) | |
366 | { | |
367 | 123 | this.ignoreReloadExceptions = ignoreReloadExceptions; |
368 | 123 | } |
369 | ||
370 | /** | |
371 | * Adds a new configuration to this combined configuration. It is possible | |
372 | * (but not mandatory) to give the new configuration a name. This name must | |
373 | * be unique, otherwise a {@code ConfigurationRuntimeException} will | |
374 | * be thrown. With the optional {@code at} argument you can specify | |
375 | * where in the resulting node structure the content of the added | |
376 | * configuration should appear. This is a string that uses dots as property | |
377 | * delimiters (independent on the current expression engine). For instance | |
378 | * if you pass in the string {@code "database.tables"}, | |
379 | * all properties of the added configuration will occur in this branch. | |
380 | * | |
381 | * @param config the configuration to add (must not be <b>null</b>) | |
382 | * @param name the name of this configuration (can be <b>null</b>) | |
383 | * @param at the position of this configuration in the combined tree (can be | |
384 | * <b>null</b>) | |
385 | */ | |
386 | public void addConfiguration(AbstractConfiguration config, String name, | |
387 | String at) | |
388 | { | |
389 | 390 | if (config == null) |
390 | { | |
391 | 1 | throw new IllegalArgumentException( |
392 | "Added configuration must not be null!"); | |
393 | } | |
394 | 389 | if (name != null && namedConfigurations.containsKey(name)) |
395 | { | |
396 | 1 | throw new ConfigurationRuntimeException( |
397 | "A configuration with the name '" | |
398 | + name | |
399 | + "' already exists in this combined configuration!"); | |
400 | } | |
401 | ||
402 | 388 | ConfigData cd = new ConfigData(config, name, at); |
403 | 388 | if (getLogger().isDebugEnabled()) |
404 | { | |
405 | 30 | getLogger().debug("Adding configuration " + config + " with name " + name); |
406 | } | |
407 | 388 | configurations.add(cd); |
408 | 388 | if (name != null) |
409 | { | |
410 | 264 | namedConfigurations.put(name, config); |
411 | } | |
412 | ||
413 | 388 | config.addConfigurationListener(this); |
414 | 388 | invalidate(); |
415 | 388 | } |
416 | ||
417 | /** | |
418 | * Adds a new configuration to this combined configuration with an optional | |
419 | * name. The new configuration's properties will be added under the root of | |
420 | * the combined node structure. | |
421 | * | |
422 | * @param config the configuration to add (must not be <b>null</b>) | |
423 | * @param name the name of this configuration (can be <b>null</b>) | |
424 | */ | |
425 | public void addConfiguration(AbstractConfiguration config, String name) | |
426 | { | |
427 | 47 | addConfiguration(config, name, null); |
428 | 47 | } |
429 | ||
430 | /** | |
431 | * Adds a new configuration to this combined configuration. The new | |
432 | * configuration is not given a name. Its properties will be added under the | |
433 | * root of the combined node structure. | |
434 | * | |
435 | * @param config the configuration to add (must not be <b>null</b>) | |
436 | */ | |
437 | public void addConfiguration(AbstractConfiguration config) | |
438 | { | |
439 | 23 | addConfiguration(config, null, null); |
440 | 22 | } |
441 | ||
442 | /** | |
443 | * Returns the number of configurations that are contained in this combined | |
444 | * configuration. | |
445 | * | |
446 | * @return the number of contained configurations | |
447 | */ | |
448 | public int getNumberOfConfigurations() | |
449 | { | |
450 | 2184 | return configurations.size(); |
451 | } | |
452 | ||
453 | /** | |
454 | * Returns the configuration at the specified index. The contained | |
455 | * configurations are numbered in the order they were added to this combined | |
456 | * configuration. The index of the first configuration is 0. | |
457 | * | |
458 | * @param index the index | |
459 | * @return the configuration at this index | |
460 | */ | |
461 | public Configuration getConfiguration(int index) | |
462 | { | |
463 | 54 | ConfigData cd = configurations.get(index); |
464 | 54 | return cd.getConfiguration(); |
465 | } | |
466 | ||
467 | /** | |
468 | * Returns the configuration with the given name. This can be <b>null</b> | |
469 | * if no such configuration exists. | |
470 | * | |
471 | * @param name the name of the configuration | |
472 | * @return the configuration with this name | |
473 | */ | |
474 | public Configuration getConfiguration(String name) | |
475 | { | |
476 | 33 | return namedConfigurations.get(name); |
477 | } | |
478 | ||
479 | /** | |
480 | * Returns a List of all the configurations that have been added. | |
481 | * @return A List of all the configurations. | |
482 | * @since 1.7 | |
483 | */ | |
484 | public List<AbstractConfiguration> getConfigurations() | |
485 | { | |
486 | 5 | List<AbstractConfiguration> list = new ArrayList<AbstractConfiguration>(configurations.size()); |
487 | 5 | for (ConfigData cd : configurations) |
488 | { | |
489 | 15 | list.add(cd.getConfiguration()); |
490 | } | |
491 | 5 | return list; |
492 | } | |
493 | ||
494 | /** | |
495 | * Returns a List of the names of all the configurations that have been | |
496 | * added in the order they were added. A NULL value will be present in | |
497 | * the list for each configuration that was added without a name. | |
498 | * @return A List of all the configuration names. | |
499 | * @since 1.7 | |
500 | */ | |
501 | public List<String> getConfigurationNameList() | |
502 | { | |
503 | 1 | List<String> list = new ArrayList<String>(configurations.size()); |
504 | 1 | for (ConfigData cd : configurations) |
505 | { | |
506 | 3 | list.add(cd.getName()); |
507 | } | |
508 | 1 | return list; |
509 | } | |
510 | ||
511 | /** | |
512 | * Removes the specified configuration from this combined configuration. | |
513 | * | |
514 | * @param config the configuration to be removed | |
515 | * @return a flag whether this configuration was found and could be removed | |
516 | */ | |
517 | public boolean removeConfiguration(Configuration config) | |
518 | { | |
519 | 5 | for (int index = 0; index < getNumberOfConfigurations(); index++) |
520 | { | |
521 | 4 | if (configurations.get(index).getConfiguration() == config) |
522 | { | |
523 | 4 | removeConfigurationAt(index); |
524 | 4 | return true; |
525 | } | |
526 | } | |
527 | ||
528 | 1 | return false; |
529 | } | |
530 | ||
531 | /** | |
532 | * Removes the configuration at the specified index. | |
533 | * | |
534 | * @param index the index | |
535 | * @return the removed configuration | |
536 | */ | |
537 | public Configuration removeConfigurationAt(int index) | |
538 | { | |
539 | 6 | ConfigData cd = configurations.remove(index); |
540 | 6 | if (cd.getName() != null) |
541 | { | |
542 | 4 | namedConfigurations.remove(cd.getName()); |
543 | } | |
544 | 6 | cd.getConfiguration().removeConfigurationListener(this); |
545 | 6 | invalidate(); |
546 | 6 | return cd.getConfiguration(); |
547 | } | |
548 | ||
549 | /** | |
550 | * Removes the configuration with the specified name. | |
551 | * | |
552 | * @param name the name of the configuration to be removed | |
553 | * @return the removed configuration (<b>null</b> if this configuration | |
554 | * was not found) | |
555 | */ | |
556 | public Configuration removeConfiguration(String name) | |
557 | { | |
558 | 3 | Configuration conf = getConfiguration(name); |
559 | 3 | if (conf != null) |
560 | { | |
561 | 2 | removeConfiguration(conf); |
562 | } | |
563 | 3 | return conf; |
564 | } | |
565 | ||
566 | /** | |
567 | * Returns a set with the names of all configurations contained in this | |
568 | * combined configuration. Of course here are only these configurations | |
569 | * listed, for which a name was specified when they were added. | |
570 | * | |
571 | * @return a set with the names of the contained configurations (never | |
572 | * <b>null</b>) | |
573 | */ | |
574 | public Set<String> getConfigurationNames() | |
575 | { | |
576 | 15 | return namedConfigurations.keySet(); |
577 | } | |
578 | ||
579 | /** | |
580 | * Invalidates this combined configuration. This means that the next time a | |
581 | * property is accessed the combined node structure must be re-constructed. | |
582 | * Invalidation of a combined configuration also means that an event of type | |
583 | * {@code EVENT_COMBINED_INVALIDATE} is fired. Note that while other | |
584 | * events most times appear twice (once before and once after an update), | |
585 | * this event is only fired once (after update). | |
586 | */ | |
587 | public void invalidate() | |
588 | { | |
589 | 15505 | reloadRequired = true; |
590 | 15505 | fireEvent(EVENT_COMBINED_INVALIDATE, null, null, false); |
591 | 15505 | } |
592 | ||
593 | /** | |
594 | * Event listener call back for configuration update events. This method is | |
595 | * called whenever one of the contained configurations was modified. It | |
596 | * invalidates this combined configuration. | |
597 | * | |
598 | * @param event the update event | |
599 | */ | |
600 | public void configurationChanged(ConfigurationEvent event) | |
601 | { | |
602 | 29255 | if (event.getType() == AbstractFileConfiguration.EVENT_CONFIG_CHANGED) |
603 | { | |
604 | 0 | fireEvent(event.getType(), event.getPropertyName(), event.getPropertyValue(), event.isBeforeUpdate()); |
605 | } | |
606 | 29255 | else if (!event.isBeforeUpdate()) |
607 | { | |
608 | 14656 | invalidate(); |
609 | } | |
610 | 29255 | } |
611 | ||
612 | /** | |
613 | * Returns the configuration root node of this combined configuration. This | |
614 | * method will construct a combined node structure using the current node | |
615 | * combiner if necessary. | |
616 | * | |
617 | * @return the combined root node | |
618 | */ | |
619 | @Override | |
620 | public ConfigurationNode getRootNode() | |
621 | { | |
622 | 44582 | synchronized (getReloadLock()) |
623 | { | |
624 | 44582 | if (reloadRequired || combinedRoot == null) |
625 | { | |
626 | 2140 | combinedRoot = constructCombinedNode(); |
627 | 2140 | reloadRequired = false; |
628 | } | |
629 | 44582 | return combinedRoot; |
630 | 0 | } |
631 | } | |
632 | ||
633 | /** | |
634 | * Clears this configuration. All contained configurations will be removed. | |
635 | */ | |
636 | @Override | |
637 | public void clear() | |
638 | { | |
639 | 196 | fireEvent(EVENT_CLEAR, null, null, true); |
640 | 196 | configurations = new ArrayList<ConfigData>(); |
641 | 196 | namedConfigurations = new HashMap<String, AbstractConfiguration>(); |
642 | 196 | fireEvent(EVENT_CLEAR, null, null, false); |
643 | 196 | invalidate(); |
644 | 196 | } |
645 | ||
646 | /** | |
647 | * Returns a copy of this object. This implementation performs a deep clone, | |
648 | * i.e. all contained configurations will be cloned, too. For this to work, | |
649 | * all contained configurations must be cloneable. Registered event | |
650 | * listeners won't be cloned. The clone will use the same node combiner than | |
651 | * the original. | |
652 | * | |
653 | * @return the copied object | |
654 | */ | |
655 | @Override | |
656 | public Object clone() | |
657 | { | |
658 | 2 | CombinedConfiguration copy = (CombinedConfiguration) super.clone(); |
659 | 2 | copy.clear(); |
660 | 2 | for (ConfigData cd : configurations) |
661 | { | |
662 | 4 | copy.addConfiguration((AbstractConfiguration) ConfigurationUtils |
663 | .cloneConfiguration(cd.getConfiguration()), cd.getName(), | |
664 | cd.getAt()); | |
665 | } | |
666 | ||
667 | 2 | copy.setRootNode(new DefaultConfigurationNode()); |
668 | 2 | return copy; |
669 | } | |
670 | ||
671 | /** | |
672 | * Returns the configuration source, in which the specified key is defined. | |
673 | * This method will determine the configuration node that is identified by | |
674 | * the given key. The following constellations are possible: | |
675 | * <ul> | |
676 | * <li>If no node object is found for this key, <b>null</b> is returned.</li> | |
677 | * <li>If the key maps to multiple nodes belonging to different | |
678 | * configuration sources, a {@code IllegalArgumentException} is | |
679 | * thrown (in this case no unique source can be determined).</li> | |
680 | * <li>If exactly one node is found for the key, the (child) configuration | |
681 | * object, to which the node belongs is determined and returned.</li> | |
682 | * <li>For keys that have been added directly to this combined | |
683 | * configuration and that do not belong to the namespaces defined by | |
684 | * existing child configurations this configuration will be returned.</li> | |
685 | * </ul> | |
686 | * | |
687 | * @param key the key of a configuration property | |
688 | * @return the configuration, to which this property belongs or <b>null</b> | |
689 | * if the key cannot be resolved | |
690 | * @throws IllegalArgumentException if the key maps to multiple properties | |
691 | * and the source cannot be determined, or if the key is <b>null</b> | |
692 | * @since 1.5 | |
693 | */ | |
694 | public Configuration getSource(String key) | |
695 | { | |
696 | 7 | if (key == null) |
697 | { | |
698 | 1 | throw new IllegalArgumentException("Key must not be null!"); |
699 | } | |
700 | ||
701 | 6 | List<ConfigurationNode> nodes = fetchNodeList(key); |
702 | 6 | if (nodes.isEmpty()) |
703 | { | |
704 | 1 | return null; |
705 | } | |
706 | ||
707 | 5 | Iterator<ConfigurationNode> it = nodes.iterator(); |
708 | 5 | Configuration source = findSourceConfiguration(it.next()); |
709 | 9 | while (it.hasNext()) |
710 | { | |
711 | 5 | Configuration src = findSourceConfiguration(it.next()); |
712 | 5 | if (src != source) |
713 | { | |
714 | 1 | throw new IllegalArgumentException("The key " + key |
715 | + " is defined by multiple sources!"); | |
716 | } | |
717 | 4 | } |
718 | ||
719 | 4 | return source; |
720 | } | |
721 | ||
722 | /** | |
723 | * Evaluates the passed in property key and returns a list with the matching | |
724 | * configuration nodes. This implementation also evaluates the | |
725 | * <em>force reload check</em> flag. If it is set, | |
726 | * {@code performReloadCheck()} is invoked. | |
727 | * | |
728 | * @param key the property key | |
729 | * @return a list with the matching configuration nodes | |
730 | */ | |
731 | @Override | |
732 | protected List<ConfigurationNode> fetchNodeList(String key) | |
733 | { | |
734 | 44543 | if (isForceReloadCheck()) |
735 | { | |
736 | 43346 | performReloadCheck(); |
737 | } | |
738 | ||
739 | 44540 | return super.fetchNodeList(key); |
740 | } | |
741 | ||
742 | /** | |
743 | * Triggers the contained configurations to perform a reload check if | |
744 | * necessary. This method is called when a property of this combined | |
745 | * configuration is accessed and the {@code forceReloadCheck} property | |
746 | * is set to <b>true</b>. | |
747 | * | |
748 | * @see #setForceReloadCheck(boolean) | |
749 | * @since 1.6 | |
750 | */ | |
751 | protected void performReloadCheck() | |
752 | { | |
753 | 43346 | for (ConfigData cd : configurations) |
754 | { | |
755 | try | |
756 | { | |
757 | // simply retrieve a property; this is enough for | |
758 | // triggering a reload | |
759 | 86695 | cd.getConfiguration().getProperty(PROP_RELOAD_CHECK); |
760 | } | |
761 | 3 | catch (Exception ex) |
762 | { | |
763 | 3 | if (!ignoreReloadExceptions) |
764 | { | |
765 | 3 | throw new ConfigurationRuntimeException(ex); |
766 | } | |
767 | 173384 | } |
768 | } | |
769 | 43343 | } |
770 | ||
771 | /** | |
772 | * Creates the root node of this combined configuration. | |
773 | * | |
774 | * @return the combined root node | |
775 | */ | |
776 | private ConfigurationNode constructCombinedNode() | |
777 | { | |
778 | 2140 | if (getNumberOfConfigurations() < 1) |
779 | { | |
780 | 21 | if (getLogger().isDebugEnabled()) |
781 | { | |
782 | 0 | getLogger().debug("No configurations defined for " + this); |
783 | } | |
784 | 21 | return new ViewNode(); |
785 | } | |
786 | ||
787 | else | |
788 | { | |
789 | 2119 | Iterator<ConfigData> it = configurations.iterator(); |
790 | 2119 | ConfigurationNode node = it.next().getTransformedRoot(); |
791 | 4268 | while (it.hasNext()) |
792 | { | |
793 | 2149 | node = getNodeCombiner().combine(node, |
794 | it.next().getTransformedRoot()); | |
795 | } | |
796 | 2119 | if (getLogger().isDebugEnabled()) |
797 | { | |
798 | 13 | ByteArrayOutputStream os = new ByteArrayOutputStream(); |
799 | 13 | PrintStream stream = new PrintStream(os); |
800 | 13 | TreeUtils.printTree(stream, node); |
801 | 13 | getLogger().debug(os.toString()); |
802 | } | |
803 | 2119 | return node; |
804 | } | |
805 | } | |
806 | ||
807 | /** | |
808 | * Determines the configuration that owns the specified node. | |
809 | * | |
810 | * @param node the node | |
811 | * @return the owning configuration | |
812 | */ | |
813 | private Configuration findSourceConfiguration(ConfigurationNode node) | |
814 | { | |
815 | 10 | synchronized (getReloadLock()) |
816 | { | |
817 | 10 | ConfigurationNode root = null; |
818 | 10 | ConfigurationNode current = node; |
819 | ||
820 | // find the root node in this hierarchy | |
821 | 40 | while (current != null) |
822 | { | |
823 | 30 | root = current; |
824 | 30 | current = current.getParentNode(); |
825 | } | |
826 | ||
827 | // Check with the root nodes of the child configurations | |
828 | 10 | for (ConfigData cd : configurations) |
829 | { | |
830 | 13 | if (root == cd.getRootNode()) |
831 | { | |
832 | 9 | return cd.getConfiguration(); |
833 | } | |
834 | } | |
835 | 1 | } |
836 | ||
837 | 1 | return this; |
838 | } | |
839 | ||
840 | /** | |
841 | * An internal helper class for storing information about contained | |
842 | * configurations. | |
843 | */ | |
844 | class ConfigData | |
845 | { | |
846 | /** Stores a reference to the configuration. */ | |
847 | private AbstractConfiguration configuration; | |
848 | ||
849 | /** Stores the name under which the configuration is stored. */ | |
850 | private String name; | |
851 | ||
852 | /** Stores the at information as path of nodes. */ | |
853 | private Collection<String> atPath; | |
854 | ||
855 | /** Stores the at string.*/ | |
856 | private String at; | |
857 | ||
858 | /** Stores the root node for this child configuration.*/ | |
859 | private ConfigurationNode rootNode; | |
860 | ||
861 | /** | |
862 | * Creates a new instance of {@code ConfigData} and initializes | |
863 | * it. | |
864 | * | |
865 | * @param config the configuration | |
866 | * @param n the name | |
867 | * @param at the at position | |
868 | */ | |
869 | public ConfigData(AbstractConfiguration config, String n, String at) | |
870 | 388 | { |
871 | 388 | configuration = config; |
872 | 388 | name = n; |
873 | 388 | atPath = parseAt(at); |
874 | 388 | this.at = at; |
875 | 388 | } |
876 | ||
877 | /** | |
878 | * Returns the stored configuration. | |
879 | * | |
880 | * @return the configuration | |
881 | */ | |
882 | public AbstractConfiguration getConfiguration() | |
883 | { | |
884 | 91061 | return configuration; |
885 | } | |
886 | ||
887 | /** | |
888 | * Returns the configuration's name. | |
889 | * | |
890 | * @return the name | |
891 | */ | |
892 | public String getName() | |
893 | { | |
894 | 17 | return name; |
895 | } | |
896 | ||
897 | /** | |
898 | * Returns the at position of this configuration. | |
899 | * | |
900 | * @return the at position | |
901 | */ | |
902 | public String getAt() | |
903 | { | |
904 | 4 | return at; |
905 | } | |
906 | ||
907 | /** | |
908 | * Returns the root node for this child configuration. | |
909 | * | |
910 | * @return the root node of this child configuration | |
911 | * @since 1.5 | |
912 | */ | |
913 | public ConfigurationNode getRootNode() | |
914 | { | |
915 | 13 | return rootNode; |
916 | } | |
917 | ||
918 | /** | |
919 | * Returns the transformed root node of the stored configuration. The | |
920 | * term "transformed" means that an eventually defined at path | |
921 | * has been applied. | |
922 | * | |
923 | * @return the transformed root node | |
924 | */ | |
925 | public ConfigurationNode getTransformedRoot() | |
926 | { | |
927 | 4268 | ViewNode result = new ViewNode(); |
928 | 4268 | ViewNode atParent = result; |
929 | ||
930 | 4268 | if (atPath != null) |
931 | { | |
932 | // Build the complete path | |
933 | 18 | for (String p : atPath) |
934 | { | |
935 | 20 | ViewNode node = new ViewNode(); |
936 | 20 | node.setName(p); |
937 | 20 | atParent.addChild(node); |
938 | 20 | atParent = node; |
939 | 20 | } |
940 | } | |
941 | ||
942 | // Copy data of the root node to the new path | |
943 | 4268 | ConfigurationNode root = ConfigurationUtils |
944 | .convertToHierarchical(getConfiguration(), | |
945 | getConversionExpressionEngine()).getRootNode(); | |
946 | 4268 | atParent.appendChildren(root); |
947 | 4268 | atParent.appendAttributes(root); |
948 | 4268 | rootNode = root; |
949 | ||
950 | 4268 | return result; |
951 | } | |
952 | ||
953 | /** | |
954 | * Splits the at path into its components. | |
955 | * | |
956 | * @param at the at string | |
957 | * @return a collection with the names of the single components | |
958 | */ | |
959 | private Collection<String> parseAt(String at) | |
960 | { | |
961 | 388 | if (at == null) |
962 | { | |
963 | 368 | return null; |
964 | } | |
965 | ||
966 | 20 | Collection<String> result = new ArrayList<String>(); |
967 | 20 | DefaultConfigurationKey.KeyIterator it = new DefaultConfigurationKey( |
968 | AT_ENGINE, at).iterator(); | |
969 | 42 | while (it.hasNext()) |
970 | { | |
971 | 22 | result.add(it.nextKey()); |
972 | } | |
973 | 20 | return result; |
974 | } | |
975 | } | |
976 | } |