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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.configuration2.builder.combined;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import org.apache.commons.configuration2.CombinedConfiguration;
import org.apache.commons.configuration2.Configuration;
import org.apache.commons.configuration2.ConfigurationLookup;
import org.apache.commons.configuration2.HierarchicalConfiguration;
import org.apache.commons.configuration2.SystemConfiguration;
import org.apache.commons.configuration2.XMLConfiguration;
import org.apache.commons.configuration2.beanutils.BeanDeclaration;
import org.apache.commons.configuration2.beanutils.BeanHelper;
import org.apache.commons.configuration2.beanutils.CombinedBeanDeclaration;
import org.apache.commons.configuration2.beanutils.XMLBeanDeclaration;
import org.apache.commons.configuration2.builder.BasicBuilderParameters;
import org.apache.commons.configuration2.builder.BasicConfigurationBuilder;
import org.apache.commons.configuration2.builder.BuilderParameters;
import org.apache.commons.configuration2.builder.ConfigurationBuilder;
import org.apache.commons.configuration2.builder.ConfigurationBuilderEvent;
import org.apache.commons.configuration2.builder.FileBasedBuilderParametersImpl;
import org.apache.commons.configuration2.builder.FileBasedBuilderProperties;
import org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.XMLBuilderParametersImpl;
import org.apache.commons.configuration2.builder.XMLBuilderProperties;
import org.apache.commons.configuration2.event.EventListener;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.interpol.ConfigurationInterpolator;
import org.apache.commons.configuration2.interpol.Lookup;
import org.apache.commons.configuration2.io.FileSystem;
import org.apache.commons.configuration2.resolver.CatalogResolver;
import org.apache.commons.configuration2.tree.DefaultExpressionEngineSymbols;
import org.apache.commons.configuration2.tree.OverrideCombiner;
import org.apache.commons.configuration2.tree.UnionCombiner;
import org.xml.sax.EntityResolver;
/**
*
* A specialized {@code ConfigurationBuilder} implementation that creates a {@link CombinedConfiguration} from multiple
* configuration sources defined by an XML-based configuration definition file.
*
*
* This class provides an easy and flexible means for loading multiple configuration sources and combining the results
* into a single configuration object. The sources to be loaded are defined in an XML document that can contain certain
* tags representing the different supported configuration classes. If such a tag is found, a corresponding
* {@code ConfigurationBuilder} class is instantiated and initialized using the classes of the {@code beanutils} package
* (namely {@link org.apache.commons.configuration2.beanutils.XMLBeanDeclaration XMLBeanDeclaration} will be used to
* extract the configuration's initialization parameters, which allows for complex initialization scenarios).
*
*
* It is also possible to add custom tags to the configuration definition file. For this purpose an implementation of
* {@link CombinedConfigurationBuilderProvider} has to be created which is responsible for the creation of a
* {@code ConfigurationBuilder} associated with the custom tag. An instance of this class has to be registered at the
* {@link CombinedBuilderParametersImpl} object which is used to initialize this {@code CombinedConfigurationBuilder}.
* This provider will then be called when the corresponding custom tag is detected. For many default configuration
* classes providers are already registered.
*
*
* The configuration definition file has the following basic structure:
*
*
*
* <configuration systemProperties="properties file name">
* <header>
* <!-- Optional meta information about the combined configuration -->
* </header>
* <override>
* <!-- Declarations for override configurations -->
* </override>
* <additional>
* <!-- Declarations for union configurations -->
* </additional>
* </configuration>
*
*
*
* The name of the root element (here {@code configuration}) is arbitrary. The optional {@code systemProperties}
* attribute identifies the path to a property file containing properties that should be added to the system properties.
* If specified on the root element, the system properties are set before the rest of the configuration is processed.
*
*
* There are two sections (both of them are optional) for declaring override and additional
* configurations. Configurations in the former section are evaluated in the order of their declaration, and properties
* of configurations declared earlier hide those of configurations declared later. Configurations in the latter section
* are combined to a union configuration, i.e. all of their properties are added to a large hierarchical configuration.
* Configuration declarations that occur as direct children of the root element are treated as override declarations.
*
*
* Each configuration declaration consists of a tag whose name is associated with a
* {@code CombinedConfigurationBuilderProvider}. This can be one of the predefined tags like {@code properties}, or
* {@code xml}, or a custom tag, for which a configuration builder provider was registered (as described above).
* Attributes and sub elements with specific initialization parameters can be added. There are some reserved attributes
* with a special meaning that can be used in every configuration declaration:
*
*
* Standard attributes for configuration declarations
*
* Attribute
* Meaning
*
*
* {@code config-name}
* Allows specifying a name for this configuration. This name can be used to obtain a reference to the configuration
* from the resulting combined configuration (see below). It can also be passed to the {@link #getNamedBuilder(String)}
* method.
*
*
* {@code config-at}
* With this attribute an optional prefix can be specified for the properties of the corresponding
* configuration.
*
*
* {@code config-optional}
* Declares a configuration source as optional. This means that errors that occur when creating the configuration
* are ignored.
*
*
* {@code config-reload}
* Many configuration sources support a reloading mechanism. For those sources it is possible to enable reloading by
* providing this attribute with a value of true.
*
*
*
* The optional header section can contain some meta data about the created configuration itself. For instance,
* it is possible to set further properties of the {@code NodeCombiner} objects used for constructing the resulting
* configuration.
*
*
* The default configuration object returned by this builder is an instance of the {@link CombinedConfiguration} class.
* This allows for convenient access to the configuration objects maintained by the combined configuration (e.g. for
* updates of single configuration objects). It has also the advantage that the properties stored in all declared
* configuration objects are collected and transformed into a single hierarchical structure, which can be accessed using
* different expression engines. The actual {@code CombinedConfiguration} implementation can be overridden by specifying
* the class in the config-class attribute of the result element.
*
*
* A custom EntityResolver can be used for all XMLConfigurations by adding
*
*
*
* <entity-resolver config-class="EntityResolver fully qualified class name">
*
*
*
* A specific CatalogResolver can be specified for all XMLConfiguration sources by adding
*
*
*
* <entity-resolver catalogFiles="comma separated list of catalog files">
*
*
*
* Additional ConfigurationProviders can be added by configuring them in the header section.
*
*
*
* <providers>
* <provider config-tag="tag name" config-class="provider fully qualified class name"/>
* </providers>
*
*
*
* Additional variable resolvers can be added by configuring them in the header section.
*
*
*
* <lookups>
* <lookup config-prefix="prefix" config-class="StrLookup fully qualified class name"/>
* </lookups>
*
*
*
* All declared override configurations are directly added to the resulting combined configuration. If they are given
* names (using the {@code config-name} attribute), they can directly be accessed using the
* {@code getConfiguration(String)} method of {@code CombinedConfiguration}. The additional configurations are
* altogether added to another combined configuration, which uses a union combiner. Then this union configuration is
* added to the resulting combined configuration under the name defined by the {@code ADDITIONAL_NAME} constant. The
* {@link #getNamedBuilder(String)} method can be used to access the {@code ConfigurationBuilder} objects for all
* configuration sources which have been assigned a name; care has to be taken that these names are unique.
*
*
* @since 1.3
*/
public class CombinedConfigurationBuilder extends BasicConfigurationBuilder {
/**
* A data class for storing information about all configuration sources defined for a combined builder.
*/
private final class ConfigurationSourceData {
/** A list with data for all builders for override configurations. */
private final List overrideDeclarations;
/** A list with data for all builders for union configurations. */
private final List unionDeclarations;
/** A list with the builders for override configurations. */
private final List> overrideBuilders;
/** A list with the builders for union configurations. */
private final List> unionBuilders;
/** A map for direct access to a builder by its name. */
private final Map> namedBuilders;
/** A collection with all child builders. */
private final Collection> allBuilders;
/** A listener for reacting on changes of sub builders. */
private final EventListener changeListener;
/**
* Creates a new instance of {@code ConfigurationSourceData}.
*/
public ConfigurationSourceData() {
overrideDeclarations = new ArrayList<>();
unionDeclarations = new ArrayList<>();
overrideBuilders = new ArrayList<>();
unionBuilders = new ArrayList<>();
namedBuilders = new HashMap<>();
allBuilders = new LinkedList<>();
changeListener = createBuilderChangeListener();
}
/**
* Creates a new configuration using the specified builder and adds it to the resulting combined configuration.
*
* @param ccResult the resulting combined configuration
* @param decl the current {@code ConfigurationDeclaration}
* @param builder the configuration builder
* @throws ConfigurationException if an error occurs
*/
private void addChildConfiguration(final CombinedConfiguration ccResult, final ConfigurationDeclaration decl,
final ConfigurationBuilder builder) throws ConfigurationException {
try {
ccResult.addConfiguration(builder.getConfiguration(), decl.getName(), decl.getAt());
} catch (final ConfigurationException cex) {
// ignore exceptions for optional configurations
if (!decl.isOptional()) {
throw cex;
}
}
}
/**
* Returns a set with the names of all known named builders.
*
* @return the names of the available sub builders
*/
public Set builderNames() {
return namedBuilders.keySet();
}
/**
* Frees resources used by this object and performs clean up. This method is called when the owning builder is reset.
*/
public void cleanUp() {
getChildBuilders().forEach(b -> b.removeEventListener(ConfigurationBuilderEvent.RESET, changeListener));
namedBuilders.clear();
}
/**
* Processes the declaration of configuration builder providers, creates the corresponding builder if necessary, obtains
* configurations, and adds them to the specified result configuration.
*
* @param ccResult the result configuration.
* @param srcDecl the collection with the declarations of configuration sources to process.
* @param builders List of configuration builders.
* @return a list with configuration builders.
* @throws ConfigurationException if an error occurs.
*/
public List> createAndAddConfigurations(final CombinedConfiguration ccResult,
final List srcDecl, final List> builders) throws ConfigurationException {
final boolean createBuilders = builders.isEmpty();
final List> newBuilders;
if (createBuilders) {
newBuilders = new ArrayList<>(srcDecl.size());
} else {
newBuilders = builders;
}
for (int i = 0; i < srcDecl.size(); i++) {
final ConfigurationBuilder b;
if (createBuilders) {
b = createConfigurationBuilder(srcDecl.get(i));
newBuilders.add(b);
} else {
b = builders.get(i);
}
addChildConfiguration(ccResult, srcDecl.get(i), b);
}
return newBuilders;
}
/**
* Creates a listener for builder change events. This listener is registered at all builders for child configurations.
*/
private EventListener createBuilderChangeListener() {
return event -> resetResult();
}
/**
* Creates a configuration builder based on a source declaration in the definition configuration.
*
* @param decl the current {@code ConfigurationDeclaration}
* @return the newly created builder
* @throws ConfigurationException if an error occurs
*/
private ConfigurationBuilder createConfigurationBuilder(final ConfigurationDeclaration decl) throws ConfigurationException {
final ConfigurationBuilderProvider provider = providerForTag(decl.getConfiguration().getRootElementName());
if (provider == null) {
throw new ConfigurationException("Unsupported configuration source: " + decl.getConfiguration().getRootElementName());
}
final ConfigurationBuilder builder = provider.getConfigurationBuilder(decl);
if (decl.getName() != null) {
namedBuilders.put(decl.getName(), builder);
}
allBuilders.add(builder);
builder.addEventListener(ConfigurationBuilderEvent.RESET, changeListener);
return builder;
}
/**
* Finds the override configurations that are defined as top level elements in the configuration definition file. This
* method fetches the child elements of the root node and removes the nodes that represent other configuration sections.
* The remaining nodes are treated as definitions for override configurations.
*
* @param config the definition configuration
* @return a list with sub configurations for the top level override configurations
*/
private List> fetchTopLevelOverrideConfigs(final HierarchicalConfiguration config) {
final List> configs = config.childConfigurationsAt(null);
for (final Iterator> it = configs.iterator(); it.hasNext();) {
final String nodeName = it.next().getRootElementName();
for (final String element : CONFIG_SECTIONS) {
if (element.equals(nodeName)) {
it.remove();
break;
}
}
}
return configs;
}
/**
* Gets a collection containing the builders for all child configuration sources.
*
* @return the child configuration builders
*/
public Collection> getChildBuilders() {
return allBuilders;
}
/**
* Gets the {@code ConfigurationBuilder} with the given name. If no such builder is defined in the definition
* configuration, result is null.
*
* @param name the name of the builder in question
* @return the builder with this name or null
*/
public ConfigurationBuilder getNamedBuilder(final String name) {
return namedBuilders.get(name);
}
/**
* Gets a collection with all configuration source declarations defined in the override section.
*
* @return the override configuration builders
*/
public List getOverrideSources() {
return overrideDeclarations;
}
/**
* Gets a collection with all configuration source declarations defined in the union section.
*
* @return the union configuration builders
*/
public List getUnionSources() {
return unionDeclarations;
}
/**
* Initializes this object from the specified definition configuration.
*
* @param config the definition configuration
* @throws ConfigurationException if an error occurs
*/
public void initFromDefinitionConfiguration(final HierarchicalConfiguration config) throws ConfigurationException {
overrideDeclarations.addAll(createDeclarations(fetchTopLevelOverrideConfigs(config)));
overrideDeclarations.addAll(createDeclarations(config.childConfigurationsAt(KEY_OVERRIDE)));
unionDeclarations.addAll(createDeclarations(config.childConfigurationsAt(KEY_UNION)));
}
}
/**
* Constant for the name of the additional configuration. If the configuration definition file contains an
* {@code additional} section, a special union configuration is created and added under this name to the resulting
* combined configuration.
*/
public static final String ADDITIONAL_NAME = CombinedConfigurationBuilder.class.getName() + "/ADDITIONAL_CONFIG";
/** Constant for the name of the configuration bean factory. */
static final String CONFIG_BEAN_FACTORY_NAME = CombinedConfigurationBuilder.class.getName() + ".CONFIG_BEAN_FACTORY_NAME";
/** Constant for the reserved name attribute. */
static final String ATTR_NAME = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + XMLBeanDeclaration.RESERVED_PREFIX + "name"
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the name of the at attribute. */
static final String ATTR_ATNAME = "at";
/** Constant for the reserved at attribute. */
static final String ATTR_AT_RES = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + XMLBeanDeclaration.RESERVED_PREFIX + ATTR_ATNAME
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the at attribute without the reserved prefix. */
static final String ATTR_AT = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + ATTR_ATNAME + DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the name of the optional attribute. */
static final String ATTR_OPTIONALNAME = "optional";
/** Constant for the reserved optional attribute. */
static final String ATTR_OPTIONAL_RES = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + XMLBeanDeclaration.RESERVED_PREFIX + ATTR_OPTIONALNAME
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the optional attribute without the reserved prefix. */
static final String ATTR_OPTIONAL = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + ATTR_OPTIONALNAME
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the forceCreate attribute. */
static final String ATTR_FORCECREATE = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + XMLBeanDeclaration.RESERVED_PREFIX + "forceCreate"
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/** Constant for the reload attribute. */
static final String ATTR_RELOAD = DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_START + XMLBeanDeclaration.RESERVED_PREFIX + "reload"
+ DefaultExpressionEngineSymbols.DEFAULT_ATTRIBUTE_END;
/**
* Constant for the tag attribute for providers.
*/
static final String KEY_SYSTEM_PROPS = "[@systemProperties]";
/** Constant for the name of the header section. */
static final String SEC_HEADER = "header";
/** Constant for an expression that selects the union configurations. */
static final String KEY_UNION = "additional";
/** An array with the names of top level configuration sections. */
static final String[] CONFIG_SECTIONS = {"additional", "override", SEC_HEADER};
/**
* Constant for an expression that selects override configurations in the override section.
*/
static final String KEY_OVERRIDE = "override";
/**
* Constant for the key that points to the list nodes definition of the override combiner.
*/
static final String KEY_OVERRIDE_LIST = SEC_HEADER + ".combiner.override.list-nodes.node";
/**
* Constant for the key that points to the list nodes definition of the additional combiner.
*/
static final String KEY_ADDITIONAL_LIST = SEC_HEADER + ".combiner.additional.list-nodes.node";
/**
* Constant for the key for defining providers in the configuration file.
*/
static final String KEY_CONFIGURATION_PROVIDERS = SEC_HEADER + ".providers.provider";
/**
* Constant for the tag attribute for providers.
*/
static final String KEY_PROVIDER_KEY = XMLBeanDeclaration.ATTR_PREFIX + "tag]";
/**
* Constant for the key for defining variable resolvers
*/
static final String KEY_CONFIGURATION_LOOKUPS = SEC_HEADER + ".lookups.lookup";
/**
* Constant for the key for defining entity resolvers
*/
static final String KEY_ENTITY_RESOLVER = SEC_HEADER + ".entity-resolver";
/**
* Constant for the prefix attribute for lookups.
*/
static final String KEY_LOOKUP_KEY = XMLBeanDeclaration.ATTR_PREFIX + "prefix]";
/**
* Constant for the FileSystem.
*/
static final String FILE_SYSTEM = SEC_HEADER + ".fileSystem";
/**
* Constant for the key of the result declaration. This key can point to a bean declaration, which defines properties of
* the resulting combined configuration.
*/
static final String KEY_RESULT = SEC_HEADER + ".result";
/** Constant for the key of the combiner in the result declaration. */
static final String KEY_COMBINER = KEY_RESULT + ".nodeCombiner";
/** Constant for the XML file extension. */
static final String EXT_XML = "xml";
/** Constant for the basic configuration builder class. */
private static final String BASIC_BUILDER = "org.apache.commons.configuration2.builder.BasicConfigurationBuilder";
/** Constant for the file-based configuration builder class. */
private static final String FILE_BUILDER = "org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder";
/** Constant for the reloading file-based configuration builder class. */
private static final String RELOADING_BUILDER = "org.apache.commons.configuration2.builder.ReloadingFileBasedConfigurationBuilder";
/** Constant for the name of the file-based builder parameters class. */
private static final String FILE_PARAMS = "org.apache.commons.configuration2.builder.FileBasedBuilderParametersImpl";
/** Constant for the provider for properties files. */
private static final ConfigurationBuilderProvider PROPERTIES_PROVIDER = new FileExtensionConfigurationBuilderProvider(FILE_BUILDER, RELOADING_BUILDER,
"org.apache.commons.configuration2.XMLPropertiesConfiguration", "org.apache.commons.configuration2.PropertiesConfiguration", EXT_XML,
Collections.singletonList(FILE_PARAMS));
/** Constant for the provider for XML files. */
private static final ConfigurationBuilderProvider XML_PROVIDER = new BaseConfigurationBuilderProvider(FILE_BUILDER, RELOADING_BUILDER,
"org.apache.commons.configuration2.XMLConfiguration", Collections.singletonList("org.apache.commons.configuration2.builder.XMLBuilderParametersImpl"));
/** Constant for the provider for JNDI sources. */
private static final BaseConfigurationBuilderProvider JNDI_PROVIDER = new BaseConfigurationBuilderProvider(BASIC_BUILDER, null,
"org.apache.commons.configuration2.JNDIConfiguration",
Collections.singletonList("org.apache.commons.configuration2.builder.JndiBuilderParametersImpl"));
/** Constant for the provider for system properties. */
private static final BaseConfigurationBuilderProvider SYSTEM_PROVIDER = new BaseConfigurationBuilderProvider(BASIC_BUILDER, null,
"org.apache.commons.configuration2.SystemConfiguration", Collections.singletonList("org.apache.commons.configuration2.builder.BasicBuilderParameters"));
/** Constant for the provider for ini files. */
private static final BaseConfigurationBuilderProvider INI_PROVIDER = new BaseConfigurationBuilderProvider(FILE_BUILDER, RELOADING_BUILDER,
"org.apache.commons.configuration2.INIConfiguration", Collections.singletonList(FILE_PARAMS));
/** Constant for the provider for environment properties. */
private static final BaseConfigurationBuilderProvider ENV_PROVIDER = new BaseConfigurationBuilderProvider(BASIC_BUILDER, null,
"org.apache.commons.configuration2.EnvironmentConfiguration",
Collections.singletonList("org.apache.commons.configuration2.builder.BasicBuilderParameters"));
/** Constant for the provider for plist files. */
private static final BaseConfigurationBuilderProvider PLIST_PROVIDER = new FileExtensionConfigurationBuilderProvider(FILE_BUILDER, RELOADING_BUILDER,
"org.apache.commons.configuration2.plist.XMLPropertyListConfiguration", "org.apache.commons.configuration2.plist.PropertyListConfiguration", EXT_XML,
Collections.singletonList(FILE_PARAMS));
/** Constant for the provider for configuration definition files. */
private static final BaseConfigurationBuilderProvider COMBINED_PROVIDER = new CombinedConfigurationBuilderProvider();
/** Constant for the provider for multiple XML configurations. */
private static final MultiFileConfigurationBuilderProvider MULTI_XML_PROVIDER = new MultiFileConfigurationBuilderProvider(
"org.apache.commons.configuration2.XMLConfiguration", "org.apache.commons.configuration2.builder.XMLBuilderParametersImpl");
/** An array with the names of the default tags. */
private static final String[] DEFAULT_TAGS = {"properties", "xml", "hierarchicalXml", "plist", "ini", "system", "env", "jndi", "configuration",
"multiFile"};
/** An array with the providers for the default tags. */
private static final ConfigurationBuilderProvider[] DEFAULT_PROVIDERS = {PROPERTIES_PROVIDER, XML_PROVIDER, XML_PROVIDER, PLIST_PROVIDER, INI_PROVIDER,
SYSTEM_PROVIDER, ENV_PROVIDER, JNDI_PROVIDER, COMBINED_PROVIDER, MULTI_XML_PROVIDER};
/** A map with the default configuration builder providers. */
private static final Map DEFAULT_PROVIDERS_MAP;
static {
DEFAULT_PROVIDERS_MAP = createDefaultProviders();
}
/**
* Creates the map with the default configuration builder providers.
*
* @return the map with default providers
*/
private static Map createDefaultProviders() {
final Map providers = new HashMap<>();
for (int i = 0; i < DEFAULT_TAGS.length; i++) {
providers.put(DEFAULT_TAGS[i], DEFAULT_PROVIDERS[i]);
}
return providers;
}
/**
* Initializes the list nodes of the node combiner for the given combined configuration. This information can be set in
* the header section of the configuration definition file for both the override and the union combiners.
*
* @param cc the combined configuration to initialize
* @param defConfig the definition configuration
* @param key the key for the list nodes
*/
private static void initNodeCombinerListNodes(final CombinedConfiguration cc, final HierarchicalConfiguration defConfig, final String key) {
defConfig.getList(key).forEach(listNode -> cc.getNodeCombiner().addListNode((String) listNode));
}
/** The builder for the definition configuration. */
private ConfigurationBuilder> definitionBuilder;
/** Stores temporarily the configuration with the builder definitions. */
private HierarchicalConfiguration definitionConfiguration;
/** The object with data about configuration sources. */
private ConfigurationSourceData sourceData;
/** Stores the current parameters object. */
private CombinedBuilderParametersImpl currentParameters;
/** The current XML parameters object. */
private XMLBuilderParametersImpl currentXMLParameters;
/** The configuration that is currently constructed. */
private CombinedConfiguration currentConfiguration;
/**
* A {@code ConfigurationInterpolator} to be used as parent for all child configurations to enable cross-source
* interpolation.
*/
private ConfigurationInterpolator parentInterpolator;
/**
* Creates a new instance of {@code CombinedConfigurationBuilder}. No parameters are set.
*/
public CombinedConfigurationBuilder() {
super(CombinedConfiguration.class);
}
/**
*
* Creates a new instance of {@code CombinedConfigurationBuilder} and sets the specified initialization parameters.
*
* @param params a map with initialization parameters
*/
public CombinedConfigurationBuilder(final Map params) {
super(CombinedConfiguration.class, params);
}
/**
*
* Creates a new instance of {@code CombinedConfigurationBuilder} and sets the specified initialization parameters and
* the allowFailOnInit flag.
*
* @param params a map with initialization parameters
* @param allowFailOnInit the allowFailOnInit flag
*/
public CombinedConfigurationBuilder(final Map params, final boolean allowFailOnInit) {
super(CombinedConfiguration.class, params, allowFailOnInit);
}
/**
* Adds a listener at the given definition builder which resets this builder when a reset of the definition builder
* happens. This way it is ensured that this builder produces a new combined configuration when its definition
* configuration changes.
*
* @param defBuilder the definition builder
*/
private void addDefinitionBuilderChangeListener(final ConfigurationBuilder> defBuilder) {
defBuilder.addEventListener(ConfigurationBuilderEvent.RESET, event -> {
synchronized (this) {
reset();
definitionBuilder = defBuilder;
}
});
}
/**
*
* Returns a set with the names of all child configuration builders. A tag defining a configuration source in the
* configuration definition file can have the {@code config-name} attribute. If this attribute is present, the
* corresponding builder is assigned this name and can be directly accessed through the {@link #getNamedBuilder(String)}
* method. This method returns a collection with all available builder names.
*
*
* Important note: This method only returns a meaningful result after the result configuration has been
* created by calling {@code getConfiguration()}. If called before, always an empty set is returned.
*
*
* @return a set with the names of all builders
*/
public synchronized Set builderNames() {
if (sourceData == null) {
return Collections.emptySet();
}
return Collections.unmodifiableSet(sourceData.builderNames());
}
/**
* {@inheritDoc} This method is overridden to adapt the return type.
*/
@Override
public CombinedConfigurationBuilder configure(final BuilderParameters... params) {
super.configure(params);
return this;
}
/**
* Creates and initializes a default {@code EntityResolver} if the definition configuration contains a corresponding
* declaration.
*
* @param config the definition configuration
* @param xmlParams the (already partly initialized) object with XML parameters; here the new resolver is to be stored
* @throws ConfigurationException if an error occurs
*/
protected void configureEntityResolver(final HierarchicalConfiguration config, final XMLBuilderParametersImpl xmlParams) throws ConfigurationException {
if (config.getMaxIndex(KEY_ENTITY_RESOLVER) == 0) {
final XMLBeanDeclaration decl = new XMLBeanDeclaration(config, KEY_ENTITY_RESOLVER, true);
final EntityResolver resolver = (EntityResolver) fetchBeanHelper().createBean(decl, CatalogResolver.class);
final FileSystem fileSystem = xmlParams.getFileHandler().getFileSystem();
if (fileSystem != null) {
BeanHelper.setProperty(resolver, "fileSystem", fileSystem);
}
final String basePath = xmlParams.getFileHandler().getBasePath();
if (basePath != null) {
BeanHelper.setProperty(resolver, "baseDir", basePath);
}
final ConfigurationInterpolator ci = new ConfigurationInterpolator();
ci.registerLookups(fetchPrefixLookups());
BeanHelper.setProperty(resolver, "interpolator", ci);
xmlParams.setEntityResolver(resolver);
}
}
/**
* Creates the {@code CombinedConfiguration} for the configuration sources in the {@code <additional>} section.
* This method is called when the builder constructs the final configuration. It creates a new
* {@code CombinedConfiguration} and initializes some properties from the result configuration.
*
* @param resultConfig the result configuration (this is the configuration that will be returned by the builder)
* @return the {@code CombinedConfiguration} for the additional configuration sources
* @since 1.7
*/
protected CombinedConfiguration createAdditionalsConfiguration(final CombinedConfiguration resultConfig) {
final CombinedConfiguration addConfig = new CombinedConfiguration(new UnionCombiner());
addConfig.setListDelimiterHandler(resultConfig.getListDelimiterHandler());
return addConfig;
}
/**
* Creates {@code ConfigurationDeclaration} objects for the specified configurations.
*
* @param configs the list with configurations
* @return a collection with corresponding declarations
*/
private Collection createDeclarations(final Collection> configs) {
return configs.stream().map(c -> new ConfigurationDeclaration(this, c)).collect(Collectors.toList());
}
/**
* {@inheritDoc} This implementation evaluates the {@code result} property of the definition configuration. It creates a
* combined bean declaration with both the properties specified in the definition file and the properties defined as
* initialization parameters.
*/
@Override
protected BeanDeclaration createResultDeclaration(final Map params) throws ConfigurationException {
final BeanDeclaration paramsDecl = super.createResultDeclaration(params);
final XMLBeanDeclaration resultDecl = new XMLBeanDeclaration(getDefinitionConfiguration(), KEY_RESULT, true, CombinedConfiguration.class.getName());
return new CombinedBeanDeclaration(resultDecl, paramsDecl);
}
/**
* Creates the data object for configuration sources and the corresponding builders.
*
* @return the newly created data object
* @throws ConfigurationException if an error occurs
*/
private ConfigurationSourceData createSourceData() throws ConfigurationException {
final ConfigurationSourceData result = new ConfigurationSourceData();
result.initFromDefinitionConfiguration(getDefinitionConfiguration());
return result;
}
/**
* Creates a default builder for the definition configuration and initializes it with a parameters object. This method
* is called if no definition builder is defined in this builder's parameters. This implementation creates a default
* file-based builder which produces an {@code XMLConfiguration}; it expects a corresponding file specification. Note:
* This method is called in a synchronized block.
*
* @param builderParams the parameters object for the builder
* @return the standard builder for the definition configuration
*/
protected ConfigurationBuilder> createXMLDefinitionBuilder(final BuilderParameters builderParams) {
return new FileBasedConfigurationBuilder<>(XMLConfiguration.class).configure(builderParams);
}
/**
* Returns a map with the current prefix lookup objects. This map is obtained from the {@code ConfigurationInterpolator}
* of the configuration under construction.
*
* @return the map with current prefix lookups (may be null)
*/
private Map fetchPrefixLookups() {
final CombinedConfiguration cc = getConfigurationUnderConstruction();
return cc != null ? cc.getInterpolator().getLookups() : null;
}
/**
* Gets the current base path of this configuration builder. This is used for instance by all file-based child
* configurations.
*
* @return the base path
*/
private String getBasePath() {
return currentXMLParameters.getFileHandler().getBasePath();
}
/**
* Gets a collection with the builders for all child configuration sources. This method can be used by derived
* classes providing additional functionality on top of the declared configuration sources. It only returns a defined
* value during construction of the result configuration instance.
*
* @return a collection with the builders for child configuration sources
*/
protected synchronized Collection> getChildBuilders() {
return sourceData.getChildBuilders();
}
/**
* Gets the configuration object that is currently constructed. This method can be called during construction of the
* result configuration. It is intended for internal usage, e.g. some specialized builder providers need access to this
* configuration to perform advanced initialization.
*
* @return the configuration that us currently under construction
*/
CombinedConfiguration getConfigurationUnderConstruction() {
return currentConfiguration;
}
/**
* Gets the {@code ConfigurationBuilder} which creates the definition configuration.
*
* @return the builder for the definition configuration
* @throws ConfigurationException if an error occurs
*/
public synchronized ConfigurationBuilder> getDefinitionBuilder() throws ConfigurationException {
if (definitionBuilder == null) {
definitionBuilder = setupDefinitionBuilder(getParameters());
addDefinitionBuilderChangeListener(definitionBuilder);
}
return definitionBuilder;
}
/**
* Gets the configuration containing the definition of the combined configuration to be created. This method only
* returns a defined result during construction of the result configuration. The definition configuration is obtained
* from the definition builder at first access and then stored temporarily to ensure that during result construction
* always the same configuration instance is used. (Otherwise, it would be possible that the definition builder returns
* a different instance when queried multiple times.)
*
* @return the definition configuration
* @throws ConfigurationException if an error occurs
*/
protected HierarchicalConfiguration getDefinitionConfiguration() throws ConfigurationException {
if (definitionConfiguration == null) {
definitionConfiguration = getDefinitionBuilder().getConfiguration();
}
return definitionConfiguration;
}
/**
*
* Gets the configuration builder with the given name. With this method a builder of a child configuration which was
* given a name in the configuration definition file can be accessed directly.
*
*
* Important note: This method only returns a meaningful result after the result configuration has been
* created by calling {@code getConfiguration()}. If called before, always an exception is thrown.
*
*
* @param name the name of the builder in question
* @return the child configuration builder with this name
* @throws ConfigurationException if information about named builders is not yet available or no builder with this name
* exists
*/
public synchronized ConfigurationBuilder getNamedBuilder(final String name) throws ConfigurationException {
if (sourceData == null) {
throw new ConfigurationException("Information about child builders" + " has not been setup yet! Call getConfiguration() first.");
}
final ConfigurationBuilder builder = sourceData.getNamedBuilder(name);
if (builder == null) {
throw new ConfigurationException("Builder cannot be resolved: " + name);
}
return builder;
}
/**
* Obtains the data object for the configuration sources and the corresponding builders. This object is created on first
* access and reset when the definition builder sends a change event. This method is called in a synchronized block.
*
* @return the object with information about configuration sources
* @throws ConfigurationException if an error occurs
*/
private ConfigurationSourceData getSourceData() throws ConfigurationException {
if (sourceData == null) {
if (currentParameters == null) {
setUpCurrentParameters();
setUpCurrentXMLParameters();
}
sourceData = createSourceData();
}
return sourceData;
}
/**
* Initializes a bean using the current {@code BeanHelper}. This is needed by builder providers when the configuration
* objects for sub builders are constructed.
*
* @param bean the bean to be initialized
* @param decl the {@code BeanDeclaration}
*/
void initBean(final Object bean, final BeanDeclaration decl) {
fetchBeanHelper().initBean(bean, decl);
}
/**
* Initializes basic builder parameters for a child configuration with default settings set for this builder. This
* implementation ensures that all {@code Lookup} objects are propagated to child configurations and interpolation is
* setup correctly.
*
* @param params the parameters object
*/
private void initChildBasicParameters(final BasicBuilderParameters params) {
params.setPrefixLookups(fetchPrefixLookups());
params.setParentInterpolator(parentInterpolator);
if (currentParameters.isInheritSettings()) {
params.inheritFrom(getParameters());
}
}
/**
* Initializes a parameters object for a child builder. This combined configuration builder has a bunch of properties
* which may be inherited by child configurations, e.g. the base path, the file system, etc. While processing the
* builders for child configurations, this method is called for each parameters object for a child builder. It
* initializes some properties of the passed in parameters objects which are derived from this parent builder.
*
* @param params the parameters object to be initialized
*/
protected void initChildBuilderParameters(final BuilderParameters params) {
initDefaultChildParameters(params);
if (params instanceof BasicBuilderParameters) {
initChildBasicParameters((BasicBuilderParameters) params);
}
if (params instanceof XMLBuilderProperties) {
initChildXMLParameters((XMLBuilderProperties) params);
}
if (params instanceof FileBasedBuilderProperties) {
initChildFileBasedParameters((FileBasedBuilderProperties) params);
}
if (params instanceof CombinedBuilderParametersImpl) {
initChildCombinedParameters((CombinedBuilderParametersImpl) params);
}
}
/**
* Initializes a parameters object for a combined configuration builder with properties already set for this parent
* builder. This implementation deals only with a subset of properties. Other properties are already handled by the
* specialized builder provider.
*
* @param params the parameters object
*/
private void initChildCombinedParameters(final CombinedBuilderParametersImpl params) {
params.registerMissingProviders(currentParameters);
params.setBasePath(getBasePath());
}
/**
* Initializes the event listeners of the specified builder from this object. This method is used to inherit all
* listeners from a parent builder.
*
* @param dest the destination builder object which is to be initialized
*/
void initChildEventListeners(final BasicConfigurationBuilder dest) {
copyEventListeners(dest);
}
/**
* Initializes a parameters object for a file-based configuration with properties already set for this parent builder.
* This method handles properties like a default file system or a base path.
*
* @param params the parameters object
*/
private void initChildFileBasedParameters(final FileBasedBuilderProperties params) {
params.setBasePath(getBasePath());
params.setFileSystem(currentXMLParameters.getFileHandler().getFileSystem());
}
/**
* Initializes a parameters object for an XML configuration with properties already set for this parent builder.
*
* @param params the parameters object
*/
private void initChildXMLParameters(final XMLBuilderProperties params) {
params.setEntityResolver(currentXMLParameters.getEntityResolver());
}
/**
* Initializes the default base path for all file-based child configuration sources. The base path can be explicitly
* defined in the parameters of this builder. Otherwise, if the definition builder is a file-based builder, it is
* obtained from there.
*
* @throws ConfigurationException if an error occurs
*/
private void initDefaultBasePath() throws ConfigurationException {
assert currentParameters != null : "Current parameters undefined!";
if (currentParameters.getBasePath() != null) {
currentXMLParameters.setBasePath(currentParameters.getBasePath());
} else {
final ConfigurationBuilder> defBuilder = getDefinitionBuilder();
if (defBuilder instanceof FileBasedConfigurationBuilder) {
@SuppressWarnings("rawtypes")
final FileBasedConfigurationBuilder fileBuilder = (FileBasedConfigurationBuilder) defBuilder;
final URL url = fileBuilder.getFileHandler().getURL();
currentXMLParameters.setBasePath(url != null ? url.toExternalForm() : fileBuilder.getFileHandler().getBasePath());
}
}
}
/**
* Executes the {@link org.apache.commons.configuration2.builder.DefaultParametersManager DefaultParametersManager}
* stored in the current parameters on the passed in parameters object. If default handlers have been registered for
* this type of parameters, an initialization is now performed. This method is called before the parameters object is
* initialized from the configuration definition file. So default values can be overridden later with concrete property
* definitions.
*
* @param params the parameters to be initialized
* @throws org.apache.commons.configuration2.ex.ConfigurationRuntimeException if an error occurs when copying properties
*/
private void initDefaultChildParameters(final BuilderParameters params) {
currentParameters.getChildDefaultParametersManager().initializeParameters(params);
}
/**
* Creates and initializes a default {@code FileSystem} if the definition configuration contains a corresponding
* declaration. The file system returned by this method is used as default for all file-based child configuration
* sources.
*
* @param config the definition configuration
* @return the default {@code FileSystem} (may be null)
* @throws ConfigurationException if an error occurs
*/
protected FileSystem initFileSystem(final HierarchicalConfiguration config) throws ConfigurationException {
if (config.getMaxIndex(FILE_SYSTEM) == 0) {
final XMLBeanDeclaration decl = new XMLBeanDeclaration(config, FILE_SYSTEM);
return (FileSystem) fetchBeanHelper().createBean(decl);
}
return null;
}
/**
* {@inheritDoc} This implementation processes the definition configuration in order to
*
* - initialize the resulting {@code CombinedConfiguration}
* - determine the builders for all configuration sources
* - populate the resulting {@code CombinedConfiguration}
*
*/
@Override
protected void initResultInstance(final CombinedConfiguration result) throws ConfigurationException {
super.initResultInstance(result);
currentConfiguration = result;
final HierarchicalConfiguration config = getDefinitionConfiguration();
if (config.getMaxIndex(KEY_COMBINER) < 0) {
// No combiner defined => set default
result.setNodeCombiner(new OverrideCombiner());
}
setUpCurrentParameters();
initNodeCombinerListNodes(result, config, KEY_OVERRIDE_LIST);
registerConfiguredProviders(config);
setUpCurrentXMLParameters();
currentXMLParameters.setFileSystem(initFileSystem(config));
initSystemProperties(config, getBasePath());
registerConfiguredLookups(config, result);
configureEntityResolver(config, currentXMLParameters);
setUpParentInterpolator(currentConfiguration, config);
final ConfigurationSourceData data = getSourceData();
final boolean createBuilders = data.getChildBuilders().isEmpty();
final List> overrideBuilders = data.createAndAddConfigurations(result, data.getOverrideSources(),
data.overrideBuilders);
if (createBuilders) {
data.overrideBuilders.addAll(overrideBuilders);
}
if (!data.getUnionSources().isEmpty()) {
final CombinedConfiguration addConfig = createAdditionalsConfiguration(result);
result.addConfiguration(addConfig, ADDITIONAL_NAME);
initNodeCombinerListNodes(addConfig, config, KEY_ADDITIONAL_LIST);
final List> unionBuilders = data.createAndAddConfigurations(addConfig, data.unionDeclarations,
data.unionBuilders);
if (createBuilders) {
data.unionBuilders.addAll(unionBuilders);
}
}
result.isEmpty(); // this sets up the node structure
currentConfiguration = null;
}
/**
* Handles a file with system properties that may be defined in the definition configuration. If such property file is
* configured, all of its properties are added to the system properties.
*
* @param config the definition configuration
* @param basePath the base path defined for this builder (may be null)
* @throws ConfigurationException if an error occurs.
*/
protected void initSystemProperties(final HierarchicalConfiguration config, final String basePath) throws ConfigurationException {
final String fileName = config.getString(KEY_SYSTEM_PROPS);
if (fileName != null) {
try {
SystemConfiguration.setSystemProperties(basePath, fileName);
} catch (final Exception ex) {
throw new ConfigurationException("Error setting system properties from " + fileName, ex);
}
}
}
/**
* Returns the {@code ConfigurationBuilderProvider} for the given tag. This method is called during creation of the
* result configuration. (It is not allowed to call it at another point of time; result is then unpredictable!) It
* supports all default providers and custom providers added through the parameters object as well.
*
* @param tagName the name of the tag
* @return the provider that was registered for this tag or null if there is none
*/
protected ConfigurationBuilderProvider providerForTag(final String tagName) {
return currentParameters.providerForTag(tagName);
}
/**
* Processes custom {@link Lookup} objects that might be declared in the definition configuration. Each {@code Lookup}
* object is registered at the definition configuration and at the result configuration. It is also added to all child
* configurations added to the resulting combined configuration.
*
* @param defConfig the definition configuration
* @param resultConfig the resulting configuration
* @throws ConfigurationException if an error occurs
*/
protected void registerConfiguredLookups(final HierarchicalConfiguration defConfig, final Configuration resultConfig) throws ConfigurationException {
final Map lookups = defConfig.configurationsAt(KEY_CONFIGURATION_LOOKUPS).stream().collect(
Collectors.toMap(config -> config.getString(KEY_LOOKUP_KEY), config -> (Lookup) fetchBeanHelper().createBean(new XMLBeanDeclaration(config))));
if (!lookups.isEmpty()) {
final ConfigurationInterpolator defCI = defConfig.getInterpolator();
if (defCI != null) {
defCI.registerLookups(lookups);
}
resultConfig.getInterpolator().registerLookups(lookups);
}
}
/**
* Registers providers defined in the configuration.
*
* @param defConfig the definition configuration
*/
private void registerConfiguredProviders(final HierarchicalConfiguration defConfig) {
defConfig.configurationsAt(KEY_CONFIGURATION_PROVIDERS).forEach(config -> {
final XMLBeanDeclaration decl = new XMLBeanDeclaration(config);
final String key = config.getString(KEY_PROVIDER_KEY);
currentParameters.registerProvider(key, (ConfigurationBuilderProvider) fetchBeanHelper().createBean(decl));
});
}
/**
* {@inheritDoc} This implementation resets some specific internal state of this builder.
*/
@Override
public synchronized void resetParameters() {
super.resetParameters();
definitionBuilder = null;
definitionConfiguration = null;
currentParameters = null;
currentXMLParameters = null;
if (sourceData != null) {
sourceData.cleanUp();
sourceData = null;
}
}
/**
* Initializes the current parameters object. This object has either been passed at builder configuration time or it is
* newly created. In any case, it is manipulated during result creation.
*/
private void setUpCurrentParameters() {
currentParameters = CombinedBuilderParametersImpl.fromParameters(getParameters(), true);
currentParameters.registerMissingProviders(DEFAULT_PROVIDERS_MAP);
}
/**
* Sets up an XML parameters object which is used to store properties related to XML and file-based configurations
* during creation of the result configuration. The properties stored in this object can be inherited to child
* configurations.
*
* @throws ConfigurationException if an error occurs
*/
private void setUpCurrentXMLParameters() throws ConfigurationException {
currentXMLParameters = new XMLBuilderParametersImpl();
initDefaultBasePath();
}
/**
* Obtains the {@code ConfigurationBuilder} object which provides access to the configuration containing the definition
* of the combined configuration to create. If a definition builder is defined in the parameters, it is used. Otherwise,
* we check whether the combined builder parameters object contains a parameters object for the definition builder. If
* this is the case, a builder for an {@code XMLConfiguration} is created and configured with this object. As a last
* resort, it is looked for a {@link FileBasedBuilderParametersImpl} object in the properties. If found, also a XML
* configuration builder is created which loads this file. Note: This method is called from a synchronized block.
*
* @param params the current parameters for this builder
* @return the builder for the definition configuration
* @throws ConfigurationException if an error occurs
*/
protected ConfigurationBuilder> setupDefinitionBuilder(final Map params)
throws ConfigurationException {
final CombinedBuilderParametersImpl cbParams = CombinedBuilderParametersImpl.fromParameters(params);
if (cbParams != null) {
final ConfigurationBuilder> defBuilder = cbParams.getDefinitionBuilder();
if (defBuilder != null) {
return defBuilder;
}
if (cbParams.getDefinitionBuilderParameters() != null) {
return createXMLDefinitionBuilder(cbParams.getDefinitionBuilderParameters());
}
}
final BuilderParameters fileParams = FileBasedBuilderParametersImpl.fromParameters(params);
if (fileParams != null) {
return createXMLDefinitionBuilder(fileParams);
}
throw new ConfigurationException("No builder for configuration definition specified!");
}
/**
* Sets up a parent {@code ConfigurationInterpolator} object. This object has a default {@link Lookup} querying the
* resulting combined configuration. Thus interpolation works globally across all configuration sources.
*
* @param resultConfig the result configuration
* @param defConfig the definition configuration
*/
private void setUpParentInterpolator(final Configuration resultConfig, final Configuration defConfig) {
parentInterpolator = new ConfigurationInterpolator();
parentInterpolator.addDefaultLookup(new ConfigurationLookup(resultConfig));
final ConfigurationInterpolator defInterpolator = defConfig.getInterpolator();
if (defInterpolator != null) {
defInterpolator.setParentInterpolator(parentInterpolator);
}
}
}