    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.Set;
    020
    021import org.apache.commons.configuration2.HierarchicalConfiguration;
    022import org.apache.commons.configuration2.beanutils.XMLBeanDeclaration;
    023
    024/**
    025 * <p>
    026 * A specialized {@code BeanDeclaration} implementation that represents the declaration of a configuration source.
    027 * </p>
    028 * <p>
    029 * Instances of this class are able to extract all information about a configuration source from the configuration
    030 * definition file. The declaration of a configuration source is very similar to a bean declaration processed by
    031 * {@code XMLBeanDeclaration}. There are very few differences, e.g. some reserved attributes like {@code optional} and
    032 * {@code at}, and the fact that a bean factory is never needed.
    033 * </p>
    034 *
    035 * @since 2.0
    036 */
    037public class ConfigurationDeclaration extends XMLBeanDeclaration {
    038    /** Stores a reference to the associated configuration builder. */
    039    private final CombinedConfigurationBuilder configurationBuilder;
    040
    041    /**
    042     * Creates a new instance of {@code ConfigurationDeclaration} and initializes it.
    043     *
    044     * @param builder the associated configuration builder
    045     * @param config the configuration this declaration is based onto
    046     */
    047    public ConfigurationDeclaration(final CombinedConfigurationBuilder builder, final HierarchicalConfiguration<?> config) {
    048        super(config);
    049        configurationBuilder = builder;
    050    }
    051
    052    /**
    053     * Returns the associated configuration builder.
    054     *
    055     * @return the configuration builder
    056     */
    057    public CombinedConfigurationBuilder getConfigurationBuilder() {
    058        return configurationBuilder;
    059    }
    060
    061    /**
    062     * Returns the value of the {@code at} attribute.
    063     *
    064     * @return the value of the {@code at} attribute (can be <b>null</b>)
    065     */
    066    public String getAt() {
    067        final String result = this.getConfiguration().getString(CombinedConfigurationBuilder.ATTR_AT_RES);
    068        return result == null ? this.getConfiguration().getString(CombinedConfigurationBuilder.ATTR_AT) : result;
    069    }
    070
    071    /**
    072     * Returns a flag whether this is an optional configuration.
    073     *
    074     * @return a flag if this declaration points to an optional configuration
    075     */
    076    public boolean isOptional() {
    077        Boolean value = this.getConfiguration().getBoolean(CombinedConfigurationBuilder.ATTR_OPTIONAL_RES, null);
    078        if (value == null) {
    079            value = this.getConfiguration().getBoolean(CombinedConfigurationBuilder.ATTR_OPTIONAL, Boolean.FALSE);
    080        }
    081        return value.booleanValue();
    082    }
    083
    084    /**
    085     * Returns a flag whether this configuration should always be created and added to the resulting combined configuration.
    086     * This flag is evaluated only for optional configurations whose normal creation has caused an error. If for such a
    087     * configuration the {@code forceCreate} attribute is set and the corresponding configuration provider supports this
    088     * mode, an empty configuration will be created and added to the resulting combined configuration.
    089     *
    090     * @return the value of the {@code forceCreate} attribute
    091     */
    092    public boolean isForceCreate() {
    093        return this.getConfiguration().getBoolean(CombinedConfigurationBuilder.ATTR_FORCECREATE, false);
    094    }
    095
    096    /**
    097     * Returns a flag whether a builder with reloading support should be created. This may not be supported by all
    098     * configuration builder providers.
    099     *
    100     * @return a flag whether a reloading builder should be created
    101     */
    102    public boolean isReload() {
    103        return getConfiguration().getBoolean(CombinedConfigurationBuilder.ATTR_RELOAD, false);
    104    }
    105
    106    /**
    107     * Returns the name for the represented configuration source. The name is optional, so this method can return
    108     * <b>null</b>.
    109     *
    110     * @return the name of the associated configuration source or <b>null</b>
    111     */
    112    public String getName() {
    113        return getConfiguration().getString(CombinedConfigurationBuilder.ATTR_NAME);
    114    }
    115
    116    /**
    117     * Returns the name of the bean factory. For configuration source declarations always a reserved factory is used. This
    118     * factory's name is returned by this implementation.
    119     *
    120     * @return the name of the bean factory
    121     */
    122    @Override
    123    public String getBeanFactoryName() {
    124        return CombinedConfigurationBuilder.CONFIG_BEAN_FACTORY_NAME;
    125    }
    126
    127    /**
    128     * Returns the bean's class name. This implementation will always return <b>null</b>.
    129     *
    130     * @return the name of the bean's class
    131     */
    132    @Override
    133    public String getBeanClassName() {
    134        return null;
    135    }
    136
    137    /**
    138     * {@inheritDoc} This implementation checks for additional reserved attribute names. Note that in some cases the
    139     * presence of other attribute names determine whether a name is reserved or not. For instance, per default the
    140     * attribute {@code config-at} is reserved. However, if this attribute is not present, the attribute {@code at} is also
    141     * considered as a reserved attribute. (This is mainly done for dealing with legacy configuration files supported by
    142     * earlier versions of this library.)
    143     */
    144    @Override
    145    protected boolean isReservedAttributeName(final String name) {
    146        if (super.isReservedAttributeName(name)) {
    147            return true;
    148        }
    149
    150        final Set<String> attributes = getAttributeNames();
    151        return (CombinedConfigurationBuilder.ATTR_ATNAME.equals(name) && !attributes.contains(RESERVED_PREFIX + CombinedConfigurationBuilder.ATTR_ATNAME))
    152            || (CombinedConfigurationBuilder.ATTR_OPTIONALNAME.equals(name)
    153                && !attributes.contains(RESERVED_PREFIX + CombinedConfigurationBuilder.ATTR_OPTIONALNAME));
    154    }
    155}