001 /* $Id: XercesParser.java 729116 2008-12-23 21:06:34Z rahul $
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements. See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019
020 package org.apache.commons.digester.parser;
021
022 import java.lang.reflect.Method;
023 import java.util.Properties;
024
025 import javax.xml.parsers.ParserConfigurationException;
026 import javax.xml.parsers.SAXParser;
027 import javax.xml.parsers.SAXParserFactory;
028 import javax.xml.validation.Schema;
029
030 import org.apache.commons.digester.Digester;
031 import org.apache.commons.logging.Log;
032 import org.apache.commons.logging.LogFactory;
033 import org.xml.sax.SAXException;
034 import org.xml.sax.SAXNotRecognizedException;
035 import org.xml.sax.SAXNotSupportedException;
036
037 /**
038 * Create a <code>SAXParser</code> based on the underlying Xerces version.
039 * Currently, Xerces 2.3 and up doesn't implement schema validation the same way
040 * 2.1 was. In other to support schema validation in a portable way between
041 * parser, some features/properties need to be set.
042 *
043 * @since 1.6
044 * @deprecated Create an XMLParser instance yourself, configure validation
045 * appropriately, and pass it as a parameter to the
046 * {@link Digester} constructor, or use
047 * {@link Digester#setXMLSchema(Schema)} for validation.
048 */
049
050 public class XercesParser{
051
052 /**
053 * The Log to which all SAX event related logging calls will be made.
054 */
055 protected static Log log =
056 LogFactory.getLog("org.apache.commons.digester.Digester.sax");
057
058
059 /**
060 * The JAXP 1.2 property required to set up the schema location.
061 */
062 private static final String JAXP_SCHEMA_SOURCE =
063 "http://java.sun.com/xml/jaxp/properties/schemaSource";
064
065
066 /**
067 * The JAXP 1.2 property to set up the schemaLanguage used.
068 */
069 protected static String JAXP_SCHEMA_LANGUAGE =
070 "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
071
072
073 /**
074 * Xerces dynamic validation property
075 */
076 protected static String XERCES_DYNAMIC =
077 "http://apache.org/xml/features/validation/dynamic";
078
079
080 /**
081 * Xerces schema validation property
082 */
083 protected static String XERCES_SCHEMA =
084 "http://apache.org/xml/features/validation/schema";
085
086
087 /**
088 * A <code>float</code> representing the underlying Xerces version
089 */
090 protected static float version;
091
092
093 /**
094 * The current Xerces version.
095 */
096 protected static String versionNumber = null;
097
098
099 /**
100 * Return the current Xerces version.
101 * @return the current Xerces version.
102 */
103 private static String getXercesVersion() {
104 // If for some reason we can't get the version, set it to 1.0.
105 String versionNumber = "1.0";
106 try{
107 // Use reflection to avoid a build dependency with Xerces.
108 Class<?> versionClass =
109 Class.forName("org.apache.xerces.impl.Version");
110 // Will return Xerces-J 2.x.0
111 Method method =
112 versionClass.getMethod("getVersion", (Class[])null);
113 String version = (String)method.invoke(null, (Object[])null);
114 versionNumber = version.substring( "Xerces-J".length() ,
115 version.lastIndexOf(".") );
116 } catch (Exception ex){
117 // Do nothing.
118 }
119 return versionNumber;
120 }
121
122
123 /**
124 * Create a <code>SAXParser</code> based on the underlying
125 * <code>Xerces</code> version.
126 * @param properties parser specific properties/features
127 * @return an XML Schema/DTD enabled <code>SAXParser</code>
128 */
129 public static SAXParser newSAXParser(Properties properties)
130 throws ParserConfigurationException,
131 SAXException,
132 SAXNotSupportedException {
133
134 SAXParserFactory factory =
135 (SAXParserFactory)properties.get("SAXParserFactory");
136
137 if (versionNumber == null){
138 versionNumber = getXercesVersion();
139 version = new Float( versionNumber ).floatValue();
140 }
141
142 // Note: 2.2 is completely broken (with XML Schema).
143 if (version > 2.1) {
144
145 configureXerces(factory);
146 return factory.newSAXParser();
147 } else {
148 SAXParser parser = factory.newSAXParser();
149 configureOldXerces(parser,properties);
150 return parser;
151 }
152 }
153
154
155 /**
156 * Configure schema validation as recommended by the JAXP 1.2 spec.
157 * The <code>properties</code> object may contains information about
158 * the schema local and language.
159 * @param properties parser optional info
160 */
161 private static void configureOldXerces(SAXParser parser,
162 Properties properties)
163 throws ParserConfigurationException,
164 SAXNotSupportedException {
165
166 String schemaLocation = (String)properties.get("schemaLocation");
167 String schemaLanguage = (String)properties.get("schemaLanguage");
168
169 try{
170 if (schemaLocation != null) {
171 parser.setProperty(JAXP_SCHEMA_LANGUAGE, schemaLanguage);
172 parser.setProperty(JAXP_SCHEMA_SOURCE, schemaLocation);
173 }
174 } catch (SAXNotRecognizedException e){
175 log.info(parser.getClass().getName() + ": "
176 + e.getMessage() + " not supported.");
177 }
178
179 }
180
181
182 /**
183 * Configure schema validation as recommended by the Xerces spec.
184 * Both DTD and Schema validation will be enabled simultaneously.
185 * <p>
186 * NOTE: This method is broken. It is supposed to set up validation
187 * against the schema specified in property "schemaLocation", but
188 * it doesn't.
189 *
190 * @param factory SAXParserFactory to be configured
191 */
192 private static void configureXerces(SAXParserFactory factory)
193 throws ParserConfigurationException,
194 SAXNotRecognizedException,
195 SAXNotSupportedException {
196
197 factory.setFeature(XERCES_DYNAMIC, true);
198 factory.setFeature(XERCES_SCHEMA, true);
199
200 }
201 }