001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.configuration2.builder.combined; 018 019import java.util.ArrayList; 020import java.util.Collection; 021import java.util.Collections; 022import java.util.HashMap; 023import java.util.LinkedList; 024import java.util.Map; 025 026import org.apache.commons.configuration2.ConfigurationUtils; 027import org.apache.commons.configuration2.HierarchicalConfiguration; 028import org.apache.commons.configuration2.builder.BasicBuilderParameters; 029import org.apache.commons.configuration2.builder.BuilderParameters; 030import org.apache.commons.configuration2.builder.ConfigurationBuilder; 031import org.apache.commons.configuration2.builder.DefaultParametersHandler; 032import org.apache.commons.configuration2.builder.DefaultParametersManager; 033 034/** 035 * <p> 036 * A specialized parameters object for a {@link CombinedConfigurationBuilder}. 037 * </p> 038 * <p> 039 * This class defines methods for setting properties for customizing a builder for combined configurations. Note that 040 * some of these properties can also be set in the configuration definition file. If this is the case, the settings in 041 * the definition file override the content of this object. 042 * </p> 043 * <p> 044 * This class is not thread-safe. It is intended that an instance is constructed and initialized by a single thread 045 * during configuration of a {@code ConfigurationBuilder}. 046 * </p> 047 * 048 * @since 2.0 049 */ 050public class CombinedBuilderParametersImpl extends BasicBuilderParameters implements CombinedBuilderProperties<CombinedBuilderParametersImpl> { 051 /** Constant for the key in the parameters map used by this class. */ 052 private static final String PARAM_KEY = RESERVED_PARAMETER_PREFIX + CombinedBuilderParametersImpl.class.getName(); 053 054 /** The definition configuration builder. */ 055 private ConfigurationBuilder<? extends HierarchicalConfiguration<?>> definitionBuilder; 056 057 /** A parameters object for the definition configuration builder. */ 058 private BuilderParameters definitionBuilderParameters; 059 060 /** A map with registered configuration builder providers. */ 061 private final Map<String, ConfigurationBuilderProvider> providers; 062 063 /** A list with default parameters for child configuration sources. */ 064 private final Collection<BuilderParameters> childParameters; 065 066 /** The manager for default handlers. */ 067 private DefaultParametersManager childDefaultParametersManager; 068 069 /** The base path for configuration sources to be loaded. */ 070 private String basePath; 071 072 /** A flag whether settings should be inherited by child builders. */ 073 private boolean inheritSettings; 074 075 /** 076 * Creates a new instance of {@code CombinedBuilderParametersImpl}. 077 */ 078 public CombinedBuilderParametersImpl() { 079 providers = new HashMap<>(); 080 childParameters = new LinkedList<>(); 081 inheritSettings = true; 082 } 083 084 /** 085 * Looks up an instance of this class in the specified parameters map. This is equivalent to 086 * {@code fromParameters(params, false);} 087 * 088 * @param params the map with parameters (must not be <b>null</b> 089 * @return the instance obtained from the map or <b>null</b> 090 * @throws NullPointerException if the map is <b>null</b> 091 */ 092 public static CombinedBuilderParametersImpl fromParameters(final Map<String, ?> params) { 093 return fromParameters(params, false); 094 } 095 096 /** 097 * Looks up an instance of this class in the specified parameters map and optionally creates a new one if none is found. 098 * This method can be used to obtain an instance of this class which has been stored in a parameters map. It is 099 * compatible with the {@code getParameters()} method. 100 * 101 * @param params the map with parameters (must not be <b>null</b> 102 * @param createIfMissing determines the behavior if no instance is found in the map; if <b>true</b>, a new instance 103 * with default settings is created; if <b>false</b>, <b>null</b> is returned 104 * @return the instance obtained from the map or <b>null</b> 105 * @throws NullPointerException if the map is <b>null</b> 106 */ 107 public static CombinedBuilderParametersImpl fromParameters(final Map<String, ?> params, final boolean createIfMissing) { 108 CombinedBuilderParametersImpl result = (CombinedBuilderParametersImpl) params.get(PARAM_KEY); 109 if (result == null && createIfMissing) { 110 result = new CombinedBuilderParametersImpl(); 111 } 112 return result; 113 } 114 115 /** 116 * {@inheritDoc} This implementation additionally copies some properties defined by this class. 117 */ 118 @Override 119 public void inheritFrom(final Map<String, ?> source) { 120 super.inheritFrom(source); 121 122 final CombinedBuilderParametersImpl srcParams = fromParameters(source); 123 if (srcParams != null) { 124 setChildDefaultParametersManager(srcParams.getChildDefaultParametersManager()); 125 setInheritSettings(srcParams.isInheritSettings()); 126 } 127 } 128 129 /** 130 * Returns the current value of the flag that controls whether the settings of the parent combined configuration builder 131 * should be inherited by its child configurations. 132 * 133 * @return the flag whether settings should be inherited by child configurations 134 */ 135 public boolean isInheritSettings() { 136 return inheritSettings; 137 } 138 139 @Override 140 public CombinedBuilderParametersImpl setInheritSettings(final boolean inheritSettings) { 141 this.inheritSettings = inheritSettings; 142 return this; 143 } 144 145 /** 146 * Gets the {@code ConfigurationBuilder} object for obtaining the definition configuration. 147 * 148 * @return the definition {@code ConfigurationBuilder} 149 */ 150 public ConfigurationBuilder<? extends HierarchicalConfiguration<?>> getDefinitionBuilder() { 151 return definitionBuilder; 152 } 153 154 /** 155 * Sets the {@code ConfigurationBuilder} for the definition configuration. This is the configuration which contains the 156 * configuration sources that form the combined configuration. 157 * 158 * @param builder the definition {@code ConfigurationBuilder} 159 * @return a reference to this object for method chaining 160 */ 161 @Override 162 public CombinedBuilderParametersImpl setDefinitionBuilder(final ConfigurationBuilder<? extends HierarchicalConfiguration<?>> builder) { 163 definitionBuilder = builder; 164 return this; 165 } 166 167 /** 168 * Registers the given {@code ConfigurationBuilderProvider} for the specified tag name. This means that whenever this 169 * tag is encountered in a configuration definition file, the corresponding builder provider is invoked. 170 * 171 * @param tagName the name of the tag (must not be <b>null</b>) 172 * @param provider the {@code ConfigurationBuilderProvider} (must not be <b>null</b>) 173 * @return a reference to this object for method chaining 174 * @throws IllegalArgumentException if a required parameter is missing 175 */ 176 @Override 177 public CombinedBuilderParametersImpl registerProvider(final String tagName, final ConfigurationBuilderProvider provider) { 178 if (tagName == null) { 179 throw new IllegalArgumentException("Tag name must not be null!"); 180 } 181 if (provider == null) { 182 throw new IllegalArgumentException("Provider must not be null!"); 183 } 184 185 providers.put(tagName, provider); 186 return this; 187 } 188 189 /** 190 * Registers all {@code ConfigurationBuilderProvider}s in the given map to this object which have not yet been 191 * registered. This method is mainly used for internal purposes: a {@code CombinedConfigurationBuilder} takes the 192 * providers contained in a parameters object and adds all standard providers. This way it is possible to override a 193 * standard provider by registering a provider object for the same tag name at the parameters object. 194 * 195 * @param providers a map with tag names and corresponding providers (must not be <b>null</b> or contain <b>null</b> 196 * entries) 197 * @return a reference to this object for method chaining 198 * @throws IllegalArgumentException if the map with providers is <b>null</b> or contains <b>null</b> entries 199 */ 200 public CombinedBuilderParametersImpl registerMissingProviders(final Map<String, ConfigurationBuilderProvider> providers) { 201 if (providers == null) { 202 throw new IllegalArgumentException("Map with providers must not be null!"); 203 } 204 providers.forEach((k, v) -> { 205 if (!this.providers.containsKey(k)) { 206 registerProvider(k, v); 207 } 208 }); 209 return this; 210 } 211 212 /** 213 * Registers all {@code ConfigurationBuilderProvider}s in the given parameters object which have not yet been 214 * registered. This method works like the method with the same name, but the map with providers is obtained from the 215 * passed in parameters object. 216 * 217 * @param params the parameters object from which to copy providers(must not be <b>null</b>) 218 * @return a reference to this object for method chaining 219 * @throws IllegalArgumentException if the source parameters object is <b>null</b> 220 */ 221 public CombinedBuilderParametersImpl registerMissingProviders(final CombinedBuilderParametersImpl params) { 222 if (params == null) { 223 throw new IllegalArgumentException("Source parameters must not be null!"); 224 } 225 return registerMissingProviders(params.getProviders()); 226 } 227 228 /** 229 * Gets an (unmodifiable) map with the currently registered {@code ConfigurationBuilderProvider} objects. 230 * 231 * @return the map with {@code ConfigurationBuilderProvider} objects (the keys are the tag names) 232 */ 233 public Map<String, ConfigurationBuilderProvider> getProviders() { 234 return Collections.unmodifiableMap(providers); 235 } 236 237 /** 238 * Returns the {@code ConfigurationBuilderProvider} which is registered for the specified tag name or <b>null</b> if 239 * there is no registration for this tag. 240 * 241 * @param tagName the tag name 242 * @return the provider registered for this tag or <b>null</b> 243 */ 244 public ConfigurationBuilderProvider providerForTag(final String tagName) { 245 return providers.get(tagName); 246 } 247 248 /** 249 * Gets the base path for relative names of configuration sources. Result may be <b>null</b> if no base path has been 250 * set. 251 * 252 * @return the base path for resolving relative file names 253 */ 254 public String getBasePath() { 255 return basePath; 256 } 257 258 /** 259 * Sets the base path for this combined configuration builder. Normally it it not necessary to set the base path 260 * explicitly. Per default, relative file names of configuration sources are resolved based on the location of the 261 * definition file. If this is not desired or if the definition configuration is loaded by a different means, the base 262 * path for relative file names can be specified using this method. 263 * 264 * @param path the base path for resolving relative file names 265 * @return a reference to this object for method chaining 266 */ 267 @Override 268 public CombinedBuilderParametersImpl setBasePath(final String path) { 269 basePath = path; 270 return this; 271 } 272 273 /** 274 * Gets the parameters object for the definition configuration builder if present. 275 * 276 * @return the parameters object for the definition configuration builder or <b>null</b> 277 */ 278 public BuilderParameters getDefinitionBuilderParameters() { 279 return definitionBuilderParameters; 280 } 281 282 /** 283 * Sets the parameters object for the definition configuration builder. This property is evaluated only if the 284 * definition configuration builder is not set explicitly (using the {@link #setDefinitionBuilder(ConfigurationBuilder)} 285 * method). In this case, a builder for an XML configuration is created and configured with this parameters object. 286 * 287 * @param params the parameters object for the definition configuration builder 288 * @return a reference to this object for method chaining 289 */ 290 @Override 291 public CombinedBuilderParametersImpl setDefinitionBuilderParameters(final BuilderParameters params) { 292 definitionBuilderParameters = params; 293 return this; 294 } 295 296 /** 297 * Gets a collection with default parameter objects for child configuration sources. This collection contains the 298 * same objects (in the same order) that were passed to {@code addChildParameters()}. The returned collection is a 299 * defensive copy; it can be modified, but this has no effect on the parameters stored in this object. 300 * 301 * @return a map with default parameters for child sources 302 */ 303 public Collection<? extends BuilderParameters> getDefaultChildParameters() { 304 return new ArrayList<>(childParameters); 305 } 306 307 /** 308 * Gets the {@code DefaultParametersManager} object for initializing parameter objects for child configuration 309 * sources. This method never returns <b>null</b>. If no manager was set, a new instance is created right now. 310 * 311 * @return the {@code DefaultParametersManager} for child configuration sources 312 */ 313 public DefaultParametersManager getChildDefaultParametersManager() { 314 if (childDefaultParametersManager == null) { 315 childDefaultParametersManager = new DefaultParametersManager(); 316 } 317 return childDefaultParametersManager; 318 } 319 320 /** 321 * {@inheritDoc} This implementation stores the passed in manager object. An already existing manager object (either 322 * explicitly set or created on demand) is overridden. This also removes all default handlers registered before! 323 */ 324 @Override 325 public CombinedBuilderParametersImpl setChildDefaultParametersManager(final DefaultParametersManager manager) { 326 childDefaultParametersManager = manager; 327 return this; 328 } 329 330 /** 331 * {@inheritDoc} This implementation registers the passed in handler at an internal {@link DefaultParametersManager} 332 * instance. If none was set, a new instance is created now. 333 */ 334 @Override 335 public <D> CombinedBuilderParametersImpl registerChildDefaultsHandler(final Class<D> paramClass, final DefaultParametersHandler<? super D> handler) { 336 getChildDefaultParametersManager().registerDefaultsHandler(paramClass, handler); 337 return this; 338 } 339 340 /** 341 * {@inheritDoc} This implementation registers the passed in handler at an internal {@link DefaultParametersManager} 342 * instance. If none was set, a new instance is created now. 343 */ 344 @Override 345 public <D> CombinedBuilderParametersImpl registerChildDefaultsHandler(final Class<D> paramClass, final DefaultParametersHandler<? super D> handler, 346 final Class<?> startClass) { 347 getChildDefaultParametersManager().registerDefaultsHandler(paramClass, handler, startClass); 348 return this; 349 } 350 351 /** 352 * {@inheritDoc} This implementation returns a map which contains this object itself under a specific key. The static 353 * {@code fromParameters()} method can be used to extract an instance from a parameters map. 354 */ 355 @Override 356 public Map<String, Object> getParameters() { 357 final Map<String, Object> params = super.getParameters(); 358 params.put(PARAM_KEY, this); 359 return params; 360 } 361 362 /** 363 * {@inheritDoc} This implementation also clones the parameters object for the definition builder if possible. 364 */ 365 @Override 366 public CombinedBuilderParametersImpl clone() { 367 final CombinedBuilderParametersImpl copy = (CombinedBuilderParametersImpl) super.clone(); 368 copy.setDefinitionBuilderParameters((BuilderParameters) ConfigurationUtils.cloneIfPossible(getDefinitionBuilderParameters())); 369 return copy; 370 } 371}