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1 /* 2 * $Header: /home/cvs/jakarta-commons/betwixt/src/java/org/apache/commons/betwixt/io/BeanReader.java,v 1.10 2003/01/08 22:07:21 rdonkin Exp $ 3 * $Revision: 1.10 $ 4 * $Date: 2003/01/08 22:07:21 $ 5 * 6 * ==================================================================== 7 * 8 * The Apache Software License, Version 1.1 9 * 10 * Copyright (c) 1999-2002 The Apache Software Foundation. All rights 11 * reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in 22 * the documentation and/or other materials provided with the 23 * distribution. 24 * 25 * 3. The end-user documentation included with the redistribution, if 26 * any, must include the following acknowlegement: 27 * "This product includes software developed by the 28 * Apache Software Foundation (http://www.apache.org/)." 29 * Alternately, this acknowlegement may appear in the software itself, 30 * if and wherever such third-party acknowlegements normally appear. 31 * 32 * 4. The names "The Jakarta Project", "Commons", and "Apache Software 33 * Foundation" must not be used to endorse or promote products derived 34 * from this software without prior written permission. For written 35 * permission, please contact apache@apache.org. 36 * 37 * 5. Products derived from this software may not be called "Apache" 38 * nor may "Apache" appear in their names without prior written 39 * permission of the Apache Group. 40 * 41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 52 * SUCH DAMAGE. 53 * ==================================================================== 54 * 55 * This software consists of voluntary contributions made by many 56 * individuals on behalf of the Apache Software Foundation. For more 57 * information on the Apache Software Foundation, please see 58 * <http://www.apache.org/>;. 59 * 60 * $Id: BeanReader.java,v 1.10 2003/01/08 22:07:21 rdonkin Exp $ 61 */ 62 package org.apache.commons.betwixt.io; 63 64 import java.beans.IntrospectionException; 65 import java.util.HashSet; 66 import java.util.Set; 67 68 import javax.xml.parsers.SAXParser; 69 70 import org.apache.commons.betwixt.ElementDescriptor; 71 import org.apache.commons.betwixt.XMLBeanInfo; 72 import org.apache.commons.betwixt.XMLIntrospector; 73 import org.apache.commons.digester.Digester; 74 import org.apache.commons.digester.Rule; 75 import org.apache.commons.logging.Log; 76 import org.apache.commons.logging.LogFactory; 77 import org.xml.sax.XMLReader; 78 79 /*** <p><code>BeanReader</code> reads a tree of beans from an XML document.</p> 80 * 81 * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> 82 * @version $Revision: 1.10 $ 83 */ 84 public class BeanReader extends Digester { 85 86 /*** Introspector used */ 87 private XMLIntrospector introspector = new XMLIntrospector(); 88 /*** Log used for logging (Doh!) */ 89 private Log log = LogFactory.getLog( BeanReader.class ); 90 /*** The registered classes */ 91 private Set registeredClasses = new HashSet(); 92 /*** Should the reader use <code>ID</code>'s to match */ 93 private boolean matchIDs = true; 94 95 /*** 96 * Construct a new BeanReader with default properties. 97 */ 98 public BeanReader() { 99 } 100 101 /*** 102 * Construct a new BeanReader, allowing a SAXParser to be passed in. This 103 * allows BeanReader to be used in environments which are unfriendly to 104 * JAXP1.1 (such as WebLogic 6.0). Thanks for the request to change go to 105 * James House (james@interobjective.com). This may help in places where 106 * you are able to load JAXP 1.1 classes yourself. 107 * 108 * @param parser use this <code>SAXParser</code> 109 */ 110 public BeanReader(SAXParser parser) { 111 super(parser); 112 } 113 114 /*** 115 * Construct a new BeanReader, allowing an XMLReader to be passed in. This 116 * allows BeanReader to be used in environments which are unfriendly to 117 * JAXP1.1 (such as WebLogic 6.0). Note that if you use this option you 118 * have to configure namespace and validation support yourself, as these 119 * properties only affect the SAXParser and emtpy constructor. 120 * 121 * @param reader use this <code>XMLReader</code> as source for SAX events 122 */ 123 public BeanReader(XMLReader reader) { 124 super(reader); 125 } 126 127 128 /*** 129 * Registers a bean class which is used by the reader 130 * to deduce the digester rules. 131 * 132 * @param beanClass the <code>Class</code> to be registered 133 * @throws IntrospectionException if the bean introspection fails 134 */ 135 public void registerBeanClass(Class beanClass) throws IntrospectionException { 136 if ( ! registeredClasses.contains( beanClass ) ) { 137 if ( log.isTraceEnabled() ) { 138 log.trace( "Registering class " + beanClass ); 139 } 140 registeredClasses.add( beanClass ); 141 142 // introspect and find the ElementDescriptor to use as the root 143 XMLBeanInfo xmlInfo = introspector.introspect( beanClass ); 144 ElementDescriptor elementDescriptor = xmlInfo.getElementDescriptor(); 145 146 String path = elementDescriptor.getQualifiedName(); 147 if (log.isTraceEnabled()) { 148 log.trace("Added path: " + path + ", mapped to: " + beanClass.getName()); 149 } 150 addBeanCreateRule( path, elementDescriptor, beanClass ); 151 addBeanCreateRule( "*/" + path, elementDescriptor, beanClass ); 152 } 153 } 154 155 /*** 156 * Registers a bean class at the given path expression 157 * which is used by the reader to deduce the digester rules. 158 * 159 * @param path the xml path expression where the class is to registered. 160 * This should be in digester path notation 161 * @param beanClass the <code>Class</code> to be registered 162 * @throws IntrospectionException if the bean introspection fails 163 */ 164 public void registerBeanClass(String path, Class beanClass) throws IntrospectionException { 165 if ( ! registeredClasses.contains( beanClass ) ) { 166 registeredClasses.add( beanClass ); 167 168 // introspect and find the ElementDescriptor to use as the root 169 XMLBeanInfo xmlInfo = introspector.introspect( beanClass ); 170 ElementDescriptor elementDescriptor = xmlInfo.getElementDescriptor(); 171 172 addBeanCreateRule( path, elementDescriptor, beanClass ); 173 } else { 174 log.warn("Cannot add class " + beanClass.getName() + " since it already exists"); 175 } 176 } 177 178 // Properties 179 //------------------------------------------------------------------------- 180 181 /*** 182 * <p> Get the introspector used. </p> 183 * 184 * <p> The {@link XMLBeanInfo} used to map each bean is 185 * created by the <code>XMLIntrospector</code>. 186 * One way in which the mapping can be customized is by 187 * altering the <code>XMLIntrospector</code>. </p> 188 * 189 * @return the <code>XMLIntrospector</code> used for the introspection 190 */ 191 public XMLIntrospector getXMLIntrospector() { 192 return introspector; 193 } 194 195 196 /*** 197 * <p> Set the introspector to be used. </p> 198 * 199 * <p> The {@link XMLBeanInfo} used to map each bean is 200 * created by the <code>XMLIntrospector</code>. 201 * One way in which the mapping can be customized is by 202 * altering the <code>XMLIntrospector</code>. </p> 203 * 204 * @param introspector use this introspector 205 */ 206 public void setXMLIntrospector(XMLIntrospector introspector) { 207 this.introspector = introspector; 208 } 209 210 /*** 211 * <p> Get the current level for logging. </p> 212 * 213 * @return the <code>Log</code> implementation this class logs to 214 */ 215 public Log getLog() { 216 return log; 217 } 218 219 /*** 220 * <p> Set the current logging level. </p> 221 * 222 * @param log the <code>Log</code>implementation to use for logging 223 */ 224 public void setLog(Log log) { 225 this.log = log; 226 setLogger(log); 227 } 228 229 /*** 230 * Should the reader use <code>ID</code> attributes to match beans. 231 * 232 * @return true if <code>ID</code> and <code>IDREF</code> 233 * attributes should be used to match instances 234 */ 235 public boolean getMatchIDs() { 236 return matchIDs; 237 } 238 239 /*** 240 * Set whether the read should use <code>ID</code> attributes to match beans. 241 * 242 * @param matchIDs pass true if <code>ID</code>'s should be matched 243 */ 244 public void setMatchIDs(boolean matchIDs) { 245 this.matchIDs = matchIDs; 246 } 247 248 // Implementation methods 249 //------------------------------------------------------------------------- 250 251 /*** 252 * Adds a new bean create rule for the specified path 253 * 254 * @param path the digester path at which this rule should be added 255 * @param elementDescriptor the <code>ElementDescriptor</code> describes the expected element 256 * @param beanClass the <code>Class</code> of the bean created by this rule 257 */ 258 protected void addBeanCreateRule( 259 String path, 260 ElementDescriptor elementDescriptor, 261 Class beanClass ) { 262 Rule rule = new BeanCreateRule( elementDescriptor, beanClass, path + "/" , matchIDs); 263 addRule( path, rule ); 264 265 if ( log.isDebugEnabled() ) { 266 log.debug( "Added root rule to path: " + path + " rule: " + rule ); 267 } 268 } 269 270 }

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