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
027 * declaration of a configuration source.
028 * </p>
029 * <p>
030 * Instances of this class are able to extract all information about a
031 * configuration source from the configuration definition file. The declaration
032 * of a configuration source is very similar to a bean declaration processed by
033 * {@code XMLBeanDeclaration}. There are very few differences, e.g. some
034 * reserved attributes like {@code optional} and {@code at}, and the fact that a
035 * bean factory is never needed.
036 * </p>
037 *
038 * @version $Id: ConfigurationDeclaration.java 1842194 2018-09-27 22:24:23Z ggregory $
039 * @since 2.0
040 */
041public class ConfigurationDeclaration extends XMLBeanDeclaration
042{
043    /** Stores a reference to the associated configuration builder. */
044    private final CombinedConfigurationBuilder configurationBuilder;
045
046    /**
047     * Creates a new instance of {@code ConfigurationDeclaration} and
048     * initializes it.
049     *
050     * @param builder the associated configuration builder
051     * @param config the configuration this declaration is based onto
052     */
053    public ConfigurationDeclaration(final CombinedConfigurationBuilder builder,
054            final HierarchicalConfiguration<?> config)
055    {
056        super(config);
057        configurationBuilder = builder;
058    }
059
060    /**
061     * Returns the associated configuration builder.
062     *
063     * @return the configuration builder
064     */
065    public CombinedConfigurationBuilder getConfigurationBuilder()
066    {
067        return configurationBuilder;
068    }
069
070    /**
071     * Returns the value of the {@code at} attribute.
072     *
073     * @return the value of the {@code at} attribute (can be <b>null</b>)
074     */
075    public String getAt()
076    {
077        final String result =
078                this.getConfiguration().getString(
079                        CombinedConfigurationBuilder.ATTR_AT_RES);
080        return (result == null) ? this.getConfiguration().getString(
081                CombinedConfigurationBuilder.ATTR_AT) : result;
082    }
083
084    /**
085     * Returns a flag whether this is an optional configuration.
086     *
087     * @return a flag if this declaration points to an optional configuration
088     */
089    public boolean isOptional()
090    {
091        Boolean value =
092                this.getConfiguration().getBoolean(
093                        CombinedConfigurationBuilder.ATTR_OPTIONAL_RES, null);
094        if (value == null)
095        {
096            value =
097                    this.getConfiguration().getBoolean(
098                            CombinedConfigurationBuilder.ATTR_OPTIONAL,
099                            Boolean.FALSE);
100        }
101        return value.booleanValue();
102    }
103
104    /**
105     * Returns a flag whether this configuration should always be created and
106     * added to the resulting combined configuration. This flag is evaluated
107     * only for optional configurations whose normal creation has caused an
108     * error. If for such a configuration the {@code forceCreate} attribute is
109     * set and the corresponding configuration provider supports this mode, an
110     * empty configuration will be created and added to the resulting combined
111     * configuration.
112     *
113     * @return the value of the {@code forceCreate} attribute
114     */
115    public boolean isForceCreate()
116    {
117        return this.getConfiguration().getBoolean(
118                CombinedConfigurationBuilder.ATTR_FORCECREATE, false);
119    }
120
121    /**
122     * Returns a flag whether a builder with reloading support should be
123     * created. This may not be supported by all configuration builder
124     * providers.
125     *
126     * @return a flag whether a reloading builder should be created
127     */
128    public boolean isReload()
129    {
130        return getConfiguration().getBoolean(
131                CombinedConfigurationBuilder.ATTR_RELOAD, false);
132    }
133
134    /**
135     * Returns the name for the represented configuration source. The name is
136     * optional, so this method can return <b>null</b>.
137     *
138     * @return the name of the associated configuration source or <b>null</b>
139     */
140    public String getName()
141    {
142        return getConfiguration().getString(
143                CombinedConfigurationBuilder.ATTR_NAME);
144    }
145
146    /**
147     * Returns the name of the bean factory. For configuration source
148     * declarations always a reserved factory is used. This factory's name is
149     * returned by this implementation.
150     *
151     * @return the name of the bean factory
152     */
153    @Override
154    public String getBeanFactoryName()
155    {
156        return CombinedConfigurationBuilder.CONFIG_BEAN_FACTORY_NAME;
157    }
158
159    /**
160     * Returns the bean's class name. This implementation will always return
161     * <b>null</b>.
162     *
163     * @return the name of the bean's class
164     */
165    @Override
166    public String getBeanClassName()
167    {
168        return null;
169    }
170
171    /**
172     * {@inheritDoc} This implementation checks for additional reserved
173     * attribute names. Note that in some cases the presence of other attribute
174     * names determine whether a name is reserved or not. For instance, per
175     * default the attribute {@code config-at} is reserved. However, if this
176     * attribute is not present, the attribute {@code at} is also considered as
177     * a reserved attribute. (This is mainly done for dealing with legacy
178     * configuration files supported by earlier versions of this library.)
179     */
180    @Override
181    protected boolean isReservedAttributeName(final String name)
182    {
183        if (super.isReservedAttributeName(name))
184        {
185            return true;
186        }
187
188        final Set<String> attributes = getAttributeNames();
189        return (CombinedConfigurationBuilder.ATTR_ATNAME.equals(name) && !attributes
190                .contains(RESERVED_PREFIX
191                        + CombinedConfigurationBuilder.ATTR_ATNAME))
192                || (CombinedConfigurationBuilder.ATTR_OPTIONALNAME.equals(name) && !attributes
193                        .contains(RESERVED_PREFIX
194                                + CombinedConfigurationBuilder.ATTR_OPTIONALNAME));
195    }
196}