001 /*
002 * CSVMappingParser.java
003 *
004 * Copyright (C) 2005 Anupam Sengupta ([email protected])
005 *
006 * This program is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU General Public License
008 * as published by the Free Software Foundation; either version 2
009 * of the License, or (at your option) any later version.
010 *
011 * This program is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
014 * GNU General Public License for more details.
015 *
016 * You should have received a copy of the GNU General Public License
017 * along with this program; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
019 *
020 * Version: $Revision: 1.3 $
021 */
022
023 package net.sf.anupam.csv.formatters;
024
025 import org.apache.commons.digester.Digester;
026 import org.apache.commons.digester.xmlrules.FromXmlRuleSet;
027 import org.apache.commons.logging.Log;
028 import org.apache.commons.logging.LogFactory;
029 import org.xml.sax.InputSource;
030 import org.xml.sax.SAXException;
031
032 import java.io.BufferedInputStream;
033 import java.io.FileInputStream;
034 import java.io.FileNotFoundException;
035 import java.io.IOException;
036 import java.io.InputStream;
037 import java.util.ArrayList;
038 import java.util.HashMap;
039 import java.util.List;
040 import java.util.Map;
041
042 /**
043 * XML Parser (based on Commons Digester) to parse and return the CSV formatter configuration. This is for internal use
044 * within the framwork.
045 *
046 * @author Anupam Sengupta
047 * @version $Revision: 1.3 $
048 * @see org.apache.commons.digester.Digester
049 * @since 1.5
050 */
051 class CSVFormatterConfigParser {
052
053 /**
054 * The logger to use.
055 */
056 private static final Log LOG = LogFactory
057 .getLog(CSVFormatterConfigParser.class);
058
059 /**
060 * The rule set for parsing formatter configuration.
061 */
062 private static FromXmlRuleSet ruleSet;
063
064 private static CSVFormatterConfigParser singleton;
065 private static final Map<String, FormatterConfiguration> formatCfgMapping = new HashMap<String, FormatterConfiguration>();
066 private static boolean isLoaded;
067
068 /**
069 * Constructor for CSVMappingParser.
070 */
071 private CSVFormatterConfigParser() {
072 super();
073
074
075 }
076
077 /**
078 * Returns the map of parsed format configuration beans.
079 *
080 * @param xmlFileName the XML mapping configuration file
081 * @param inClassPath flag indicating whether the XML file is in the classpath
082 * @return a map of format mappings. An empty map is returned if an error occurs
083 */
084 public synchronized Map<String, FormatterConfiguration> getFormatMappings(
085 final String xmlFileName, final boolean inClassPath) {
086
087 if (!isLoaded) {
088 loadMappings(xmlFileName, inClassPath);
089 isLoaded = true;
090 }
091
092
093 return formatCfgMapping;
094 }
095
096
097 /**
098 * Load the formatter mappings.
099 *
100 * @param xmlFileName the XML file to load the mappings from
101 * @param inClassPath indicates whether the mapping file is in the classpath
102 */
103 private void loadMappings(final String xmlFileName, final boolean inClassPath) {
104 try {
105 final InputStream xmlStream = (inClassPath)
106 ? getClass().getClassLoader()
107 .getResourceAsStream(xmlFileName)
108 : new BufferedInputStream(new FileInputStream(xmlFileName));
109
110 final InputSource inputSrc = new InputSource(xmlStream);
111 final Digester digester = new Digester();
112 digester.clear();
113
114 CSVFormatterConfigParser.ruleSet
115 .addRuleInstances(digester);
116 digester.push(new ArrayList<FormatterConfiguration>());
117 final List<FormatterConfiguration> formatMappingList = (List<FormatterConfiguration>) digester
118 .parse(inputSrc);
119
120 for (FormatterConfiguration formatConfig : formatMappingList) {
121 formatCfgMapping.put(formatConfig.getFormatterName(), formatConfig);
122 }
123 } catch (final FileNotFoundException e) {
124 LOG.warn("The XML File: "
125 + xmlFileName + " was not found", e);
126 } catch (final IOException e) {
127 LOG.warn("The XML File: "
128 + xmlFileName + " could not be read", e);
129 } catch (final SAXException e) {
130 LOG.warn("The XML File: "
131 + xmlFileName + " could not be parsed", e);
132 }
133 }
134
135 public synchronized static CSVFormatterConfigParser getConfigParser() {
136
137 if (singleton == null) {
138 final InputStream is = CSVFormatterConfigParser.class.getClassLoader()
139 .getResourceAsStream("net/sf/anupam/csv/formatters/csv-formatter-config-digester-rules.xml");
140 if (is != null) {
141 final InputSource isrc = new InputSource(is);
142 ruleSet = new FromXmlRuleSet(isrc);
143 LOG.info("Loaded Digester Rules for "
144 + CSVFormatterConfigParser.class);
145 } else {
146 LOG
147 .error("The CSV Formatter Configuration Digester Rules XML was not found");
148 }
149 singleton = new CSVFormatterConfigParser();
150 }
151 return singleton;
152 }
153 }