Source for javax.xml.parsers.SAXParserFactory

   1: /* SAXParserFactory.java -- 
   2:    Copyright (C) 2004, 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package javax.xml.parsers;
  39: 
  40: import java.io.BufferedReader;
  41: import java.io.File;
  42: import java.io.FileInputStream;
  43: import java.io.InputStream;
  44: import java.io.InputStreamReader;
  45: import java.io.IOException;
  46: import java.util.Properties;
  47: import javax.xml.validation.Schema;
  48: import org.xml.sax.SAXException;
  49: import org.xml.sax.SAXNotRecognizedException;
  50: import org.xml.sax.SAXNotSupportedException;
  51: 
  52: /**
  53:  * Factory for obtaining SAX parsers.
  54:  * Instances of this class are <em>not</em> guaranteed to be thread safe.
  55:  *
  56:  * @author (a href='mailto:dog@gnu.org'>Chris Burdess</a)
  57:  */
  58: public abstract class SAXParserFactory
  59: {
  60: 
  61:   private boolean validating;
  62:   private boolean namespaceAware;
  63:   private Schema schema;
  64:   private boolean xIncludeAware;
  65: 
  66:   protected SAXParserFactory()
  67:   {
  68:   }
  69: 
  70:   /**
  71:    * Creates a new factory instance.
  72:    * The implementation class to load is the first found in the following
  73:    * locations:
  74:    * <ol>
  75:    * <li>the <code>javax.xml.parsers.SAXParserFactory</code> system
  76:    * property</li>
  77:    * <li>the above named property value in the
  78:    * <code><i>$JAVA_HOME</i>/lib/jaxp.properties</code> file</li>
  79:    * <li>the class name specified in the
  80:    * <code>META-INF/services/javax.xml.parsers.SAXParserFactory</code>
  81:    * system resource</li>
  82:    * <li>the default factory class</li>
  83:    * </ol>
  84:    */
  85:   public static SAXParserFactory newInstance()
  86:     throws FactoryConfigurationError
  87:   {
  88:     ClassLoader loader = Thread.currentThread().getContextClassLoader();
  89:     if (loader == null)
  90:       {
  91:         loader = SAXParserFactory.class.getClassLoader();
  92:       }
  93:     String className = null;
  94:     int count = 0;
  95:     do
  96:       {
  97:         className = getFactoryClassName(loader, count++);
  98:         if (className != null)
  99:           {
 100:             try
 101:               {
 102:                 Class t = (loader != null) ? loader.loadClass(className) :
 103:                   Class.forName(className);
 104:                 return (SAXParserFactory) t.newInstance();
 105:               }
 106:             catch (ClassNotFoundException e)
 107:               {
 108:                 className = null;
 109:               }
 110:             catch (Exception e)
 111:               {
 112:                 throw new FactoryConfigurationError(e,
 113:                      "error instantiating class " + className);
 114:               }
 115:           }
 116:       }
 117:     while (className == null && count < 3);
 118:     return new gnu.xml.stream.SAXParserFactory();
 119:   }
 120: 
 121:   private static String getFactoryClassName(ClassLoader loader, int attempt)
 122:   {
 123:     final String propertyName = "javax.xml.parsers.SAXParserFactory";
 124:     switch (attempt)
 125:       {
 126:         case 0:
 127:           return System.getProperty(propertyName);
 128:         case 1:
 129:           try
 130:             {
 131:               File file = new File(System.getProperty("java.home"));
 132:               file = new File(file, "lib");
 133:               file = new File(file, "jaxp.properties");
 134:               InputStream in = new FileInputStream(file);
 135:               Properties props = new Properties();
 136:               props.load(in);
 137:               in.close();
 138:               return props.getProperty(propertyName);
 139:             }
 140:           catch (IOException e)
 141:             {
 142:               return null;
 143:             }
 144:         case 2:
 145:           try
 146:             {
 147:               String serviceKey = "/META-INF/services/" + propertyName;
 148:               InputStream in = (loader != null) ?
 149:                  loader.getResourceAsStream(serviceKey) :
 150:                 SAXParserFactory.class.getResourceAsStream(serviceKey);
 151:               if (in != null)
 152:                 {
 153:                   BufferedReader r =
 154:                      new BufferedReader(new InputStreamReader(in));
 155:                   String ret = r.readLine();
 156:                   r.close();
 157:                   return ret;
 158:                 }
 159:             }
 160:           catch (IOException e)
 161:             {
 162:             }
 163:           return null;
 164:         default:
 165:           return null;
 166:       }
 167:   }
 168: 
 169:   /**
 170:    * Creates a new parser instance using the currently specified factory
 171:    * configuration.
 172:    * @exception ParserConfigurationException if the specified configuration
 173:    * is not supported
 174:    */
 175:   public abstract SAXParser newSAXParser()
 176:     throws ParserConfigurationException, SAXException;
 177: 
 178:   /**
 179:    * Sets whether parsers obtained from this factory will be XML Namespace
 180:    * aware.
 181:    */
 182:   public void setNamespaceAware(boolean awareness)
 183:   {
 184:     namespaceAware = awareness;
 185:   }
 186: 
 187:   /**
 188:    * Sets whether parsers obtained from this factory will validate their
 189:    * input.
 190:    */
 191:   public void setValidating(boolean validating)
 192:   {
 193:     this.validating = validating;
 194:   }
 195: 
 196:   /**
 197:    * Indicates whether parsers obtained from this factory will be XML
 198:    * Namespace aware.
 199:    */
 200:   public boolean isNamespaceAware()
 201:   {
 202:     return namespaceAware;
 203:   }
 204: 
 205:   /**
 206:    * Indicates whether parsers obtained from this factory will validate
 207:    * their input.
 208:    */
 209:   public boolean isValidating()
 210:   {
 211:     return validating;
 212:   }
 213: 
 214:   /**
 215:    * Sets the specified feature for SAX2 parsers obtained from this factory.
 216:    * @param name the feature name
 217:    * @param value the featurevalue
 218:    */
 219:   public abstract void setFeature(String name, boolean value) 
 220:     throws ParserConfigurationException, SAXNotRecognizedException, 
 221:            SAXNotSupportedException;
 222: 
 223:   /**
 224:    * Returns the specified feature for SAX2 parsers obtained from this
 225:    * factory.
 226:    * @param name the feature name
 227:    */
 228:   public abstract boolean getFeature(String name) 
 229:     throws ParserConfigurationException, SAXNotRecognizedException, 
 230:            SAXNotSupportedException;
 231: 
 232:   // -- JAXP 1.3 methods --
 233: 
 234:   /**
 235:    * Returns the schema.
 236:    * @since 1.3
 237:    * @see #setSchema
 238:    */
 239:   public Schema getSchema()
 240:   {
 241:     return schema;
 242:   }
 243: 
 244:   /**
 245:    * Sets the schema.
 246:    * @since 1.3
 247:    * @see #getSchema
 248:    */
 249:   public void setSchema(Schema schema)
 250:   {
 251:     this.schema = schema;
 252:   }
 253: 
 254:   /**
 255:    * Indicates whether parsers obtained from this factory will be XInclude
 256:    * aware.
 257:    * @since 1.3
 258:    */
 259:   public boolean isXIncludeAware()
 260:   {
 261:     return xIncludeAware;
 262:   }
 263: 
 264:   /**
 265:    * Sets whether parsers obtained from this factory will be XInclude aware.
 266:    * @since 1.3
 267:    */
 268:   public void setXIncludeAware(boolean state)
 269:   {
 270:     xIncludeAware = state;
 271:   }
 272: 
 273: }