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 */
017
018package org.apache.commons.configuration2.beanutils;
019
020import java.lang.reflect.Array;
021import java.util.Collection;
022import java.util.List;
023import java.util.Objects;
024
025import org.apache.commons.beanutils.DynaBean;
026import org.apache.commons.beanutils.DynaClass;
027import org.apache.commons.configuration2.Configuration;
028import org.apache.commons.configuration2.ConfigurationMap;
029import org.apache.commons.configuration2.SubsetConfiguration;
030import org.apache.commons.logging.Log;
031import org.apache.commons.logging.LogFactory;
032
033/**
034 * The {@code ConfigurationDynaBean} dynamically reads and writes configurations properties from a wrapped
035 * configuration-collection {@link org.apache.commons.configuration2.Configuration} instance. It also implements a
036 * {@link java.util.Map} interface so that it can be used in JSP 2.0 Expression Language expressions.
037 *
038 * <p>
039 * The {@code ConfigurationDynaBean} maps nested and mapped properties to the appropriate {@code Configuration} subset
040 * using the {@link org.apache.commons.configuration2.Configuration#subset} method. Similarly, indexed properties
041 * reference lists of configuration properties using the
042 * {@link org.apache.commons.configuration2.Configuration#getList(String)} method. Setting an indexed property is
043 * supported, too.
044 * </p>
045 *
046 * <p>
047 * Note: Some of the methods expect that a dot (&quot;.&quot;) is used as property delimiter for the wrapped
048 * configuration. This is true for most of the default configurations. Hierarchical configurations, for which a specific
049 * expression engine is set, may cause problems.
050 * </p>
051 *
052 * @since 1.0-rc1
053 */
054public class ConfigurationDynaBean extends ConfigurationMap implements DynaBean {
055
056    /** Constant for the property delimiter. */
057    private static final String PROPERTY_DELIMITER = ".";
058
059    /** The logger. */
060    private static final Log LOG = LogFactory.getLog(ConfigurationDynaBean.class);
061
062    /**
063     * Constructs a new instance of {@code ConfigurationDynaBean} and sets the configuration this bean is associated with.
064     *
065     * @param configuration the configuration
066     */
067    public ConfigurationDynaBean(final Configuration configuration) {
068        super(configuration);
069        if (LOG.isTraceEnabled()) {
070            LOG.trace("ConfigurationDynaBean(" + configuration + ")");
071        }
072    }
073
074    @Override
075    public void set(final String name, final Object value) {
076        if (LOG.isTraceEnabled()) {
077            LOG.trace("set(" + name + "," + value + ")");
078        }
079        Objects.requireNonNull(value, "Error trying to set property to null.");
080
081        if (value instanceof Collection) {
082            final Collection<?> collection = (Collection<?>) value;
083            for (final Object v : collection) {
084                getConfiguration().addProperty(name, v);
085            }
086        } else if (value.getClass().isArray()) {
087            final int length = Array.getLength(value);
088            for (int i = 0; i < length; i++) {
089                getConfiguration().addProperty(name, Array.get(value, i));
090            }
091        } else {
092            getConfiguration().setProperty(name, value);
093        }
094    }
095
096    @Override
097    public Object get(final String name) {
098        if (LOG.isTraceEnabled()) {
099            LOG.trace("get(" + name + ")");
100        }
101
102        // get configuration property
103        Object result = getConfiguration().getProperty(name);
104        if (result == null) {
105            // otherwise attempt to create bean from configuration subset
106            final Configuration subset = new SubsetConfiguration(getConfiguration(), name, PROPERTY_DELIMITER);
107            if (!subset.isEmpty()) {
108                result = new ConfigurationDynaBean(subset);
109            }
110        }
111
112        if (LOG.isDebugEnabled()) {
113            LOG.debug(name + "=[" + result + "]");
114        }
115
116        if (result == null) {
117            throw new IllegalArgumentException("Property '" + name + "' does not exist.");
118        }
119        return result;
120    }
121
122    @Override
123    public boolean contains(final String name, final String key) {
124        final Configuration subset = getConfiguration().subset(name);
125        if (subset == null) {
126            throw new IllegalArgumentException("Mapped property '" + name + "' does not exist.");
127        }
128
129        return subset.containsKey(key);
130    }
131
132    @Override
133    public Object get(final String name, final int index) {
134        if (!checkIndexedProperty(name)) {
135            throw new IllegalArgumentException("Property '" + name + "' is not indexed.");
136        }
137
138        final List<Object> list = getConfiguration().getList(name);
139        return list.get(index);
140    }
141
142    @Override
143    public Object get(final String name, final String key) {
144        final Configuration subset = getConfiguration().subset(name);
145        if (subset == null) {
146            throw new IllegalArgumentException("Mapped property '" + name + "' does not exist.");
147        }
148
149        return subset.getProperty(key);
150    }
151
152    @Override
153    public DynaClass getDynaClass() {
154        return new ConfigurationDynaClass(getConfiguration());
155    }
156
157    @Override
158    public void remove(final String name, final String key) {
159        final Configuration subset = new SubsetConfiguration(getConfiguration(), name, PROPERTY_DELIMITER);
160        subset.setProperty(key, null);
161    }
162
163    @Override
164    public void set(final String name, final int index, final Object value) {
165        if (!checkIndexedProperty(name) && index > 0) {
166            throw new IllegalArgumentException("Property '" + name + "' is not indexed.");
167        }
168
169        final Object property = getConfiguration().getProperty(name);
170
171        if (property instanceof List) {
172            // This is safe because multiple values of a configuration property
173            // are always stored as lists of type Object.
174            @SuppressWarnings("unchecked")
175            final List<Object> list = (List<Object>) property;
176            list.set(index, value);
177            getConfiguration().setProperty(name, list);
178        } else if (property.getClass().isArray()) {
179            Array.set(property, index, value);
180        } else if (index == 0) {
181            getConfiguration().setProperty(name, value);
182        }
183    }
184
185    @Override
186    public void set(final String name, final String key, final Object value) {
187        getConfiguration().setProperty(name + "." + key, value);
188    }
189
190    /**
191     * Checks whether the given name references an indexed property. This implementation tests for properties of type list or
192     * array. If the property does not exist, an exception is thrown.
193     *
194     * @param name the name of the property to check
195     * @return a flag whether this is an indexed property
196     * @throws IllegalArgumentException if the property does not exist
197     */
198    private boolean checkIndexedProperty(final String name) {
199        final Object property = getConfiguration().getProperty(name);
200
201        if (property == null) {
202            throw new IllegalArgumentException("Property '" + name + "' does not exist.");
203        }
204
205        return property instanceof List || property.getClass().isArray();
206    }
207}