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    
018    package org.apache.commons.configuration;
019    
020    /**
021     * <p>A specialized SAX2 XML parser that processes configuration objects.</p>
022     *
023     * <p>This class mimics to be a SAX compliant XML parser. It is able to iterate
024     * over the keys in a configuration object and to generate corresponding SAX
025     * events. By registering a {@code ContentHandler} at an instance
026     * it is possible to perform XML processing on a configuration object.</p>
027     *
028     * @author <a
029     * href="http://commons.apache.org/configuration/team-list.html">Commons
030     * Configuration team</a>
031     * @version $Id: BaseConfigurationXMLReader.java 1206765 2011-11-27 16:46:11Z oheger $
032     */
033    public class BaseConfigurationXMLReader extends ConfigurationXMLReader
034    {
035        /** Stores the actual configuration.*/
036        private Configuration config;
037    
038        /**
039         * Creates a new instance of {@code BaseConfigurationXMLReader}.
040         */
041        public BaseConfigurationXMLReader()
042        {
043            super();
044        }
045    
046        /**
047         * Creates a new instance of {@code BaseConfigurationXMLReader} and
048         * sets the configuration object to be parsed.
049         *
050         * @param conf the configuration to be parsed
051         */
052        public BaseConfigurationXMLReader(Configuration conf)
053        {
054            this();
055            setConfiguration(conf);
056        }
057    
058        /**
059         * Returns the actual configuration to be processed.
060         *
061         * @return the actual configuration
062         */
063        public Configuration getConfiguration()
064        {
065            return config;
066        }
067    
068        /**
069         * Sets the configuration to be processed.
070         *
071         * @param conf the configuration
072         */
073        public void setConfiguration(Configuration conf)
074        {
075            config = conf;
076        }
077    
078        /**
079         * Returns the configuration to be processed.
080         *
081         * @return the actual configuration
082         */
083        @Override
084        public Configuration getParsedConfiguration()
085        {
086            return getConfiguration();
087        }
088    
089        /**
090         * The main SAX event generation method. This element uses an internal
091         * {@code HierarchicalConfigurationConverter} object to iterate over
092         * all keys in the actual configuration and to generate corresponding SAX
093         * events.
094         */
095        @Override
096        protected void processKeys()
097        {
098            fireElementStart(getRootName(), null);
099            new SAXConverter().process(getConfiguration());
100            fireElementEnd(getRootName());
101        }
102    
103        /**
104         * An internally used helper class to iterate over all configuration keys
105         * ant to generate corresponding SAX events.
106         *
107         */
108        class SAXConverter extends HierarchicalConfigurationConverter
109        {
110            /**
111             * Callback for the start of an element.
112             *
113             * @param name the element name
114             * @param value the element value
115             */
116            @Override
117            protected void elementStart(String name, Object value)
118            {
119                fireElementStart(name, null);
120                if (value != null)
121                {
122                    fireCharacters(value.toString());
123                }
124            }
125    
126            /**
127             * Callback for the end of an element.
128             *
129             * @param name the element name
130             */
131            @Override
132            protected void elementEnd(String name)
133            {
134                fireElementEnd(name);
135            }
136        }
137    }