1 /*
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.xml.transform;
27
28 /**
29 * <p>A TransformerFactory instance can be used to create
30 * {@link javax.xml.transform.Transformer} and
31 * {@link javax.xml.transform.Templates} objects.</p>
32 *
33 * <p>The system property that determines which Factory implementation
34 * to create is named <code>"javax.xml.transform.TransformerFactory"</code>.
35 * This property names a concrete subclass of the
36 * <code>TransformerFactory</code> abstract class. If the property is not
37 * defined, a platform default is be used.</p>
38 *
39 * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
40 * @author <a href="mailto:Neeraj.Bajaj@sun.com">Neeraj Bajaj</a>
41 *
42 * @since 1.5
43 */
44 public abstract class TransformerFactory {
45
46 /**
47 * Default constructor is protected on purpose.
48 */
49 protected TransformerFactory() { }
50
51
52
53 /**
54 * <p>Obtain a new instance of a <code>TransformerFactory</code>.
55 * This static method creates a new factory instance.</p>
56 * <p>This method uses the following ordered lookup procedure to determine
57 * the <code>TransformerFactory</code> implementation class to
58 * load:</p>
59 * <ul>
60 * <li>
61 * Use the <code>javax.xml.transform.TransformerFactory</code> system
62 * property.
63 * </li>
64 * <li>
65 * Use the properties file "lib/jaxp.properties" in the JRE directory.
66 * This configuration file is in standard <code>java.util.Properties
67 * </code> format and contains the fully qualified name of the
68 * implementation class with the key being the system property defined
69 * above.
70 * <br>
71 * The jaxp.properties file is read only once by the JAXP implementation
72 * and it's values are then cached for future use. If the file does not exist
73 * when the first attempt is made to read from it, no further attempts are
74 * made to check for its existence. It is not possible to change the value
75 * of any property in jaxp.properties after it has been read for the first time.
76 * </li>
77 * <li>
78 * Use the service-provider loading facilities, defined by the
79 * {@link java.util.ServiceLoader} class, to attempt to locate and load an
80 * implementation of the service.
81 * </li>
82 * <li>
83 * Otherwise, the system-default implementation is returned.
84 * </li>
85 * </ul>
86 *
87 * <p>Once an application has obtained a reference to a <code>
88 * TransformerFactory</code> it can use the factory to configure
89 * and obtain transformer instances.</p>
90 *
91 * @return new TransformerFactory instance, never null.
92 *
93 * @throws TransformerFactoryConfigurationError Thrown in case of {@linkplain
94 * java.util.ServiceConfigurationError service configuration error} or if
95 * the implementation is not available or cannot be instantiated.
96 */
97 public static TransformerFactory newInstance()
98 throws TransformerFactoryConfigurationError {
99
100 return FactoryFinder.find(
101 /* The default property name according to the JAXP spec */
102 TransformerFactory.class,
103 /* The fallback implementation class name, XSLTC */
104 "com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl");
105 }
106
107 /**
108 * <p>Obtain a new instance of a <code>TransformerFactory</code> from factory class name.
109 * This function is useful when there are multiple providers in the classpath.
110 * It gives more control to the application as it can specify which provider
111 * should be loaded.</p>
112 *
113 * <p>Once an application has obtained a reference to a <code>
114 * TransformerFactory</code> it can use the factory to configure
115 * and obtain transformer instances.</p>
116 *
117 * <h2>Tip for Trouble-shooting</h2>
118 * <p>Setting the <code>jaxp.debug</code> system property will cause
119 * this method to print a lot of debug messages
120 * to <code>System.err</code> about what it is doing and where it is looking at.</p>
121 *
122 * <p> If you have problems try:</p>
123 * <pre>
124 * java -Djaxp.debug=1 YourProgram ....
125 * </pre>
126 *
127 * @param factoryClassName fully qualified factory class name that provides implementation of <code>javax.xml.transform.TransformerFactory</code>.
128 *
129 * @param classLoader <code>ClassLoader</code> used to load the factory class. If <code>null</code>
130 * current <code>Thread</code>'s context classLoader is used to load the factory class.
131 *
132 * @return new TransformerFactory instance, never null.
133 *
134 * @throws TransformerFactoryConfigurationError
135 * if <code>factoryClassName</code> is <code>null</code>, or
136 * the factory class cannot be loaded, instantiated.
137 *
138 * @see #newInstance()
139 *
140 * @since 1.6
141 */
142 public static TransformerFactory newInstance(String factoryClassName, ClassLoader classLoader)
143 throws TransformerFactoryConfigurationError{
144
145 //do not fallback if given classloader can't find the class, throw exception
146 return FactoryFinder.newInstance(TransformerFactory.class,
147 factoryClassName, classLoader, false, false);
148 }
149 /**
150 * <p>Process the <code>Source</code> into a <code>Transformer</code>
151 * <code>Object</code>. The <code>Source</code> is an XSLT document that
152 * conforms to <a href="http://www.w3.org/TR/xslt">
153 * XSL Transformations (XSLT) Version 1.0</a>. Care must
154 * be taken not to use this <code>Transformer</code> in multiple
155 * <code>Thread</code>s running concurrently.
156 * Different <code>TransformerFactories</code> can be used concurrently by
157 * different <code>Thread</code>s.</p>
158 *
159 * @param source <code>Source </code> of XSLT document used to create
160 * <code>Transformer</code>.
161 * Examples of XML <code>Source</code>s include
162 * {@link javax.xml.transform.dom.DOMSource DOMSource},
163 * {@link javax.xml.transform.sax.SAXSource SAXSource}, and
164 * {@link javax.xml.transform.stream.StreamSource StreamSource}.
165 *
166 * @return A <code>Transformer</code> object that may be used to perform
167 * a transformation in a single <code>Thread</code>, never
168 * <code>null</code>.
169 *
170 * @throws TransformerConfigurationException Thrown if there are errors when
171 * parsing the <code>Source</code> or it is not possible to create a
172 * <code>Transformer</code> instance.
173 *
174 * @see <a href="http://www.w3.org/TR/xslt">
175 * XSL Transformations (XSLT) Version 1.0</a>
176 */
177 public abstract Transformer newTransformer(Source source)
178 throws TransformerConfigurationException;
179
180 /**
181 * <p>Create a new <code>Transformer</code> that performs a copy
182 * of the <code>Source</code> to the <code>Result</code>.
183 * i.e. the "<em>identity transform</em>".</p>
184 *
185 * @return A Transformer object that may be used to perform a transformation
186 * in a single thread, never null.
187 *
188 * @throws TransformerConfigurationException When it is not
189 * possible to create a <code>Transformer</code> instance.
190 */
191 public abstract Transformer newTransformer()
192 throws TransformerConfigurationException;
193
194 /**
195 * Process the Source into a Templates object, which is a
196 * a compiled representation of the source. This Templates object
197 * may then be used concurrently across multiple threads. Creating
198 * a Templates object allows the TransformerFactory to do detailed
199 * performance optimization of transformation instructions, without
200 * penalizing runtime transformation.
201 *
202 * @param source An object that holds a URL, input stream, etc.
203 *
204 * @return A Templates object capable of being used for transformation
205 * purposes, never <code>null</code>.
206 *
207 * @throws TransformerConfigurationException When parsing to
208 * construct the Templates object fails.
209 */
210 public abstract Templates newTemplates(Source source)
211 throws TransformerConfigurationException;
212
213 /**
214 * <p>Get the stylesheet specification(s) associated with the
215 * XML <code>Source</code> document via the
216 * <a href="http://www.w3.org/TR/xml-stylesheet/">
217 * xml-stylesheet processing instruction</a> that match the given criteria.
218 * Note that it is possible to return several stylesheets, in which case
219 * they are applied as if they were a list of imports or cascades in a
220 * single stylesheet.</p>
221 *
222 * @param source The XML source document.
223 * @param media The media attribute to be matched. May be null, in which
224 * case the prefered templates will be used (i.e. alternate = no).
225 * @param title The value of the title attribute to match. May be null.
226 * @param charset The value of the charset attribute to match. May be null.
227 *
228 * @return A <code>Source</code> <code>Object</code> suitable for passing
229 * to the <code>TransformerFactory</code>.
230 *
231 * @throws TransformerConfigurationException An <code>Exception</code>
232 * is thrown if an error occurings during parsing of the
233 * <code>source</code>.
234 *
235 * @see <a href="http://www.w3.org/TR/xml-stylesheet/">
236 * Associating Style Sheets with XML documents Version 1.0</a>
237 */
238 public abstract Source getAssociatedStylesheet(
239 Source source,
240 String media,
241 String title,
242 String charset)
243 throws TransformerConfigurationException;
244
245 /**
246 * Set an object that is used by default during the transformation
247 * to resolve URIs used in document(), xsl:import, or xsl:include.
248 *
249 * @param resolver An object that implements the URIResolver interface,
250 * or null.
251 */
252 public abstract void setURIResolver(URIResolver resolver);
253
254 /**
255 * Get the object that is used by default during the transformation
256 * to resolve URIs used in document(), xsl:import, or xsl:include.
257 *
258 * @return The URIResolver that was set with setURIResolver.
259 */
260 public abstract URIResolver getURIResolver();
261
262 //======= CONFIGURATION METHODS =======
263
264 /**
265 * <p>Set a feature for this <code>TransformerFactory</code> and <code>Transformer</code>s
266 * or <code>Template</code>s created by this factory.</p>
267 *
268 * <p>
269 * Feature names are fully qualified {@link java.net.URI}s.
270 * Implementations may define their own features.
271 * An {@link TransformerConfigurationException} is thrown if this <code>TransformerFactory</code> or the
272 * <code>Transformer</code>s or <code>Template</code>s it creates cannot support the feature.
273 * It is possible for an <code>TransformerFactory</code> to expose a feature value but be unable to change its state.
274 * </p>
275 *
276 * <p>All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature.
277 * When the feature is:</p>
278 * <ul>
279 * <li>
280 * <code>true</code>: the implementation will limit XML processing to conform to implementation limits
281 * and behave in a secure fashion as defined by the implementation.
282 * Examples include resolving user defined style sheets and functions.
283 * If XML processing is limited for security reasons, it will be reported via a call to the registered
284 * {@link ErrorListener#fatalError(TransformerException exception)}.
285 * See {@link #setErrorListener(ErrorListener listener)}.
286 * </li>
287 * <li>
288 * <code>false</code>: the implementation will processing XML according to the XML specifications without
289 * regard to possible implementation limits.
290 * </li>
291 * </ul>
292 *
293 * @param name Feature name.
294 * @param value Is feature state <code>true</code> or <code>false</code>.
295 *
296 * @throws TransformerConfigurationException if this <code>TransformerFactory</code>
297 * or the <code>Transformer</code>s or <code>Template</code>s it creates cannot support this feature.
298 * @throws NullPointerException If the <code>name</code> parameter is null.
299 */
300 public abstract void setFeature(String name, boolean value)
301 throws TransformerConfigurationException;
302
303 /**
304 * Look up the value of a feature.
305 *
306 * <p>
307 * Feature names are fully qualified {@link java.net.URI}s.
308 * Implementations may define their own features.
309 * <code>false</code> is returned if this <code>TransformerFactory</code> or the
310 * <code>Transformer</code>s or <code>Template</code>s it creates cannot support the feature.
311 * It is possible for an <code>TransformerFactory</code> to expose a feature value but be unable to change its state.
312 * </p>
313 *
314 * @param name Feature name.
315 *
316 * @return The current state of the feature, <code>true</code> or <code>false</code>.
317 *
318 * @throws NullPointerException If the <code>name</code> parameter is null.
319 */
320 public abstract boolean getFeature(String name);
321
322 /**
323 * Allows the user to set specific attributes on the underlying
324 * implementation. An attribute in this context is defined to
325 * be an option that the implementation provides.
326 * An <code>IllegalArgumentException</code> is thrown if the underlying
327 * implementation doesn't recognize the attribute.
328 * <p>
329 * All implementations that implement JAXP 1.5 or newer are required to
330 * support the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} and
331 * {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_STYLESHEET} properties.
332 * </p>
333 * <ul>
334 * <li>
335 * <p>
336 * Access to external DTDs in the source file is restricted to the protocols
337 * specified by the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} property.
338 * If access is denied during transformation due to the restriction of this property,
339 * {@link javax.xml.transform.TransformerException} will be thrown by
340 * {@link javax.xml.transform.Transformer#transform(Source, Result)}.
341 * </p>
342 * <p>
343 * Access to external DTDs in the stylesheet is restricted to the protocols
344 * specified by the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} property.
345 * If access is denied during the creation of a new transformer due to the
346 * restriction of this property,
347 * {@link javax.xml.transform.TransformerConfigurationException} will be thrown
348 * by the {@link #newTransformer(Source)} method.
349 * </p>
350 * <p>
351 * Access to external reference set by the stylesheet processing instruction,
352 * Import and Include element is restricted to the protocols specified by the
353 * {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_STYLESHEET} property.
354 * If access is denied during the creation of a new transformer due to the
355 * restriction of this property,
356 * {@link javax.xml.transform.TransformerConfigurationException} will be thrown
357 * by the {@link #newTransformer(Source)} method.
358 * </p>
359 * <p>
360 * Access to external document through XSLT document function is restricted
361 * to the protocols specified by the property. If access is denied during
362 * the transformation due to the restriction of this property,
363 * {@link javax.xml.transform.TransformerException} will be thrown by the
364 * {@link javax.xml.transform.Transformer#transform(Source, Result)} method.
365 * </p>
366 * </li>
367 * </ul>
368 *
369 * @param name The name of the attribute.
370 * @param value The value of the attribute.
371 *
372 * @throws IllegalArgumentException When implementation does not
373 * recognize the attribute.
374 */
375 public abstract void setAttribute(String name, Object value);
376
377 /**
378 * Allows the user to retrieve specific attributes on the underlying
379 * implementation.
380 * An <code>IllegalArgumentException</code> is thrown if the underlying
381 * implementation doesn't recognize the attribute.
382 *
383 * @param name The name of the attribute.
384 *
385 * @return value The value of the attribute.
386 *
387 * @throws IllegalArgumentException When implementation does not
388 * recognize the attribute.
389 */
390 public abstract Object getAttribute(String name);
391
392 /**
393 * Set the error event listener for the TransformerFactory, which
394 * is used for the processing of transformation instructions,
395 * and not for the transformation itself.
396 * An <code>IllegalArgumentException</code> is thrown if the
397 * <code>ErrorListener</code> listener is <code>null</code>.
398 *
399 * @param listener The new error listener.
400 *
401 * @throws IllegalArgumentException When <code>listener</code> is
402 * <code>null</code>
403 */
404 public abstract void setErrorListener(ErrorListener listener);
405
406 /**
407 * Get the error event handler for the TransformerFactory.
408 *
409 * @return The current error handler, which should never be null.
410 */
411 public abstract ErrorListener getErrorListener();
412
413 }