001/* SAXParserFactory.java -- 
002   Copyright (C) 2004, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.xml.parsers;
039
040import java.io.BufferedReader;
041import java.io.File;
042import java.io.FileInputStream;
043import java.io.InputStream;
044import java.io.InputStreamReader;
045import java.io.IOException;
046import java.util.Properties;
047import javax.xml.validation.Schema;
048import org.xml.sax.SAXException;
049import org.xml.sax.SAXNotRecognizedException;
050import org.xml.sax.SAXNotSupportedException;
051
052/**
053 * Factory for obtaining SAX parsers.
054 * Instances of this class are <em>not</em> guaranteed to be thread safe.
055 *
056 * @author (a href='mailto:dog@gnu.org'>Chris Burdess</a)
057 */
058public abstract class SAXParserFactory
059{
060
061  private boolean validating;
062  private boolean namespaceAware;
063  private Schema schema;
064  private boolean xIncludeAware;
065
066  protected SAXParserFactory()
067  {
068  }
069
070  /**
071   * Creates a new factory instance.
072   * The implementation class to load is the first found in the following
073   * locations:
074   * <ol>
075   * <li>the <code>javax.xml.parsers.SAXParserFactory</code> system
076   * property</li>
077   * <li>the above named property value in the
078   * <code><i>$JAVA_HOME</i>/lib/jaxp.properties</code> file</li>
079   * <li>the class name specified in the
080   * <code>META-INF/services/javax.xml.parsers.SAXParserFactory</code>
081   * system resource</li>
082   * <li>the default factory class</li>
083   * </ol>
084   */
085  public static SAXParserFactory newInstance()
086    throws FactoryConfigurationError
087  {
088    ClassLoader loader = Thread.currentThread().getContextClassLoader();
089    if (loader == null)
090      {
091        loader = SAXParserFactory.class.getClassLoader();
092      }
093    String className = null;
094    int count = 0;
095    do
096      {
097        className = getFactoryClassName(loader, count++);
098        if (className != null)
099          {
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}