001    /* XMLOutputFactory.java -- 
002       Copyright (C) 2005,2006  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package javax.xml.stream;
039    
040    import java.io.BufferedReader;
041    import java.io.File;
042    import java.io.FileInputStream;
043    import java.io.InputStream;
044    import java.io.InputStreamReader;
045    import java.io.IOException;
046    import java.io.OutputStream;
047    import java.io.Writer;
048    import java.util.Properties;
049    import javax.xml.transform.Result;
050    
051    /**
052     * Factory for obtaining XML stream and event writers for various kinds of
053     * output sink.
054     * <h3>Configuration</h3>
055     * <table>
056     * <tr>
057     * <th>Name</th>
058     * <th>Description</th>
059     * <th>Type</th>
060     * <th>Default</th>
061     * <th>Required</th>
062     * </tr>
063     * <tr>
064     * <td>javax.xml.stream.isRepairingNamespaces</td>
065     * <td>default namespace prefixes</td>
066     * <td>Boolean</td>
067     * <td>Boolean.FALSE</td>
068     * <td>yes</td>
069     * </tr>
070     * </table>
071     */
072    public abstract class XMLOutputFactory
073    {
074    
075      /**
076       * Property used to control whether to default namespace prefixes.
077       * If true, the writer will create a namespace declaration for any
078       * attribute that doesn't have a namespace declaration in scope.
079       */
080      public static final java.lang.String IS_REPAIRING_NAMESPACES = 
081        "javax.xml.stream.isRepairingNamespaces";
082    
083      protected XMLOutputFactory()
084      {
085      }
086    
087      /**
088       * Creates a new <b>output</b> factory.
089       * The implementation class to load is the first found in the following
090       * locations:
091       * <ol>
092       * <li>the <code>javax.xml.stream.XMLOutputFactory</code> system
093       * property</li>
094       * <li>the above named property value in the
095       * <code><i>$JAVA_HOME</i>/lib/stax.properties</code> file</li>
096       * <li>the class name specified in the
097       * <code>META-INF/services/javax.xml.stream.XMLOutputFactory</code>
098       * system resource</li>
099       * <li>the default factory class</li>
100       * </ol>
101       */
102      public static XMLOutputFactory newInstance()
103        throws FactoryConfigurationError
104      {
105        ClassLoader loader = Thread.currentThread().getContextClassLoader();
106        if (loader == null)
107          {
108            loader = XMLOutputFactory.class.getClassLoader();
109          }
110        String className = null;
111        int count = 0;
112        do
113          {
114            className = getFactoryClassName(loader, count++);
115            if (className != null)
116              {
117                try
118                  {
119                    Class t = (loader != null) ? loader.loadClass(className) :
120                      Class.forName(className);
121                    return (XMLOutputFactory) t.newInstance();
122                  }
123                catch (ClassNotFoundException e)
124                  {
125                    className = null;
126                  }
127                catch (Exception e)
128                  {
129                    throw new FactoryConfigurationError(e,
130                         "error instantiating class " + className);
131                  }
132              }
133          }
134        while (className == null && count < 3);
135        return new gnu.xml.stream.XMLOutputFactoryImpl();
136      }
137    
138      private static String getFactoryClassName(ClassLoader loader, int attempt)
139      {
140        final String propertyName = "javax.xml.stream.XMLOutputFactory";
141        switch (attempt)
142          {
143            case 0:
144              return System.getProperty(propertyName);
145            case 1:
146              try
147                {
148                  File file = new File(System.getProperty("java.home"));
149                  file = new File(file, "lib");
150                  file = new File(file, "stax.properties");
151                  InputStream in = new FileInputStream(file);
152                  Properties props = new Properties();
153                  props.load(in);
154                  in.close();
155                  return props.getProperty(propertyName);
156                }
157              catch (IOException e)
158                {
159                  return null;
160                }
161            case 2:
162              try
163                {
164                  String serviceKey = "/META-INF/services/" + propertyName;
165                  InputStream in = (loader != null) ?
166                     loader.getResourceAsStream(serviceKey) :
167                    XMLOutputFactory.class.getResourceAsStream(serviceKey);
168                  if (in != null)
169                    {
170                      BufferedReader r =
171                         new BufferedReader(new InputStreamReader(in));
172                      String ret = r.readLine();
173                      r.close();
174                      return ret;
175                    }
176                }
177              catch (IOException e)
178                {
179                }
180              return null;
181            default:
182              return null;
183          }
184      }
185    
186      /**
187       * Creates a new <b>input</b> factory.
188       * This appears to be an API design bug.
189       * @see javax.xml.stream.XMLInputFactory.newInstance(String,ClassLoader)
190       */
191      public static XMLInputFactory newInstance(String factoryId,
192                                                ClassLoader classLoader)
193        throws FactoryConfigurationError
194      {
195        return XMLInputFactory.newInstance(factoryId, classLoader);
196      }
197    
198      /**
199       * Creates a new stream writer.
200       */
201      public abstract XMLStreamWriter createXMLStreamWriter(Writer stream)
202        throws XMLStreamException;
203    
204      /**
205       * Creates a new stream writer.
206       */
207      public abstract XMLStreamWriter createXMLStreamWriter(OutputStream stream)
208        throws XMLStreamException;
209    
210      /**
211       * Creates a new stream writer.
212       */
213      public abstract XMLStreamWriter createXMLStreamWriter(OutputStream stream,
214                                                            String encoding)
215        throws XMLStreamException;
216    
217      /**
218       * Creates a new stream writer.
219       * @exception UnsupportedOperationException if this method is not
220       * supported
221       */
222      public abstract XMLStreamWriter createXMLStreamWriter(Result result)
223        throws XMLStreamException;
224      
225      /**
226       * Creates a new event writer.
227       * @exception UnsupportedOperationException if this method is not
228       * supported
229       */
230      public abstract XMLEventWriter createXMLEventWriter(Result result)
231        throws XMLStreamException;
232    
233      /**
234       * Creates a new event writer.
235       */
236      public abstract XMLEventWriter createXMLEventWriter(OutputStream stream)
237        throws XMLStreamException;
238    
239      /**
240       * Creates a new event writer.
241       */
242      public abstract XMLEventWriter createXMLEventWriter(OutputStream stream,
243                                                          String encoding)
244        throws XMLStreamException;
245    
246      /**
247       * Creates a new event writer.
248       */
249      public abstract XMLEventWriter createXMLEventWriter(Writer stream)
250        throws XMLStreamException;
251    
252      /**
253       * Sets the implementation-specific property of the given name.
254       * @exception IllegalArgumentException if the property is not supported
255       */
256      public abstract void setProperty(String name, Object value)
257        throws IllegalArgumentException;
258    
259      /**
260       * Returns the implementation-specific property of the given name.
261       * @exception IllegalArgumentException if the property is not supported
262       */
263      public abstract Object getProperty(String name)
264        throws IllegalArgumentException;
265    
266      /**
267       * Indicates whether the specified property is supported.
268       */
269      public abstract boolean isPropertySupported(String name);
270    
271    }
272