http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// $Id: TransformerFactory.java 884963 2009-11-27 19:11:59Z mrglavas $

package javax.xml.transform;


A TransformerFactory instance can be used to create Transformer and Templates objects.


The system property that determines which Factory implementation
to create is named "javax.xml.transform.TransformerFactory".
This property names a concrete subclass of the
TransformerFactory abstract class. If the property is not
defined, a platform default is be used.


Author:Jeff Suttor
/**
 * <p>A TransformerFactory instance can be used to create
 * {@link javax.xml.transform.Transformer} and
 * {@link javax.xml.transform.Templates} objects.</p>
 *
 * <p>The system property that determines which Factory implementation
 * to create is named <code>"javax.xml.transform.TransformerFactory"</code>.
 * This property names a concrete subclass of the
 * <code>TransformerFactory</code> abstract class. If the property is not
 * defined, a platform default is be used.</p>
 * 
 * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
 */
public abstract class TransformerFactory {
    
    
Default constructor is protected on purpose.

/**
     * Default constructor is protected on purpose.
     */
    protected TransformerFactory() { }


    /**
     * <p>Get current state of canonicalization.</p>
     * 
     * @return current state canonicalization control
     */
    /*
    public boolean getCanonicalization() {
        return canonicalState;
    }
    */
    
    /**
     * <p>Set canonicalization control to <code>true</code> or
     * </code>false</code>.</p>
     * 
     * @param state of canonicalization
     */
    /*
    public void setCanonicalization(boolean state) {
        canonicalState = state;
    }
    */

    
Obtain a new instance of a TransformerFactory.
This static method creates a new factory instance
This method uses the following ordered lookup procedure to determine
the TransformerFactory implementation class to
load:

    

  • 
Use the javax.xml.transform.TransformerFactory system
property.

    • 

  • 
Use the properties file "lib/jaxp.properties" in the JRE directory.
This configuration file is in standard java.util.Properties
 format and contains the fully qualified name of the
implementation class with the key being the system property defined
above.
The jaxp.properties file is read only once by the JAXP implementation
and it's values are then cached for future use.  If the file does not exist
when the first attempt is made to read from it, no further attempts are
made to check for its existence.  It is not possible to change the value
of any property in jaxp.properties after it has been read for the first time.

    • 

  • 
Use the Services API (as detailed in the JAR specification), if
available, to determine the classname. The Services API will look
for a classname in the file
META-INF/services/javax.xml.transform.TransformerFactory
in jars available to the runtime.

    • 

  • 
Platform default TransformerFactory instance.

    • 


Once an application has obtained a reference to a 
TransformerFactory it can use the factory to configure
and obtain parser instances.

Throws:
Returns:new TransformerFactory instance, never null.
/**
     * Obtain a new instance of a <code>TransformerFactory</code>.
     * This static method creates a new factory instance
     * This method uses the following ordered lookup procedure to determine
     * the <code>TransformerFactory</code> implementation class to
     * load:
     * <ul>
     * <li>
     * Use the <code>javax.xml.transform.TransformerFactory</code> system
     * property.
     * </li>
     * <li>
     * Use the properties file "lib/jaxp.properties" in the JRE directory.
     * This configuration file is in standard <code>java.util.Properties
     * </code> format and contains the fully qualified name of the
     * implementation class with the key being the system property defined
     * above.
     * 
     * The jaxp.properties file is read only once by the JAXP implementation
     * and it's values are then cached for future use.  If the file does not exist
     * when the first attempt is made to read from it, no further attempts are
     * made to check for its existence.  It is not possible to change the value
     * of any property in jaxp.properties after it has been read for the first time.
     * </li>
     * <li>
     * Use the Services API (as detailed in the JAR specification), if
     * available, to determine the classname. The Services API will look
     * for a classname in the file
     * <code>META-INF/services/javax.xml.transform.TransformerFactory</code>
     * in jars available to the runtime.
     * </li>
     * <li>
     * Platform default <code>TransformerFactory</code> instance.
     * </li>
     * </ul>
     *
     * Once an application has obtained a reference to a <code>
     * TransformerFactory</code> it can use the factory to configure
     * and obtain parser instances.
     *
     * @return new TransformerFactory instance, never null.
     *
     * @throws TransformerFactoryConfigurationError Thrown if the implementation
     *    is not available or cannot be instantiated.
     */
    public static TransformerFactory newInstance()
        throws TransformerFactoryConfigurationError {
        try {
            return (TransformerFactory) FactoryFinder.find(
            /* The default property name according to the JAXP spec */
            "javax.xml.transform.TransformerFactory",
            /* The fallback implementation class name */
            "org.apache.xalan.processor.TransformerFactoryImpl");
        } 
        catch (FactoryFinder.ConfigurationError e) {
            throw new TransformerFactoryConfigurationError(e.getException(), e.getMessage());
        }
    }
    
    
Throws:
Returns:new TransformerFactory instance, never null.
/**
     * @return new TransformerFactory instance, never null.
     *
     * @throws TransformerFactoryConfigurationError Thrown if the implementation
     *    is not available or cannot be instantiated.
     */
    public static TransformerFactory newInstance(String factoryClassName,
            ClassLoader classLoader) throws TransformerFactoryConfigurationError {
        if (factoryClassName == null) {
            throw new TransformerFactoryConfigurationError("factoryClassName cannot be null.");
        }
        if (classLoader == null) {
            classLoader = SecuritySupport.getContextClassLoader();
        }
        try {
            return (TransformerFactory) FactoryFinder.newInstance(factoryClassName, classLoader, false);
        }
        catch (FactoryFinder.ConfigurationError e) {
            throw new TransformerFactoryConfigurationError(e.getException(), e.getMessage());
        }
    }

    
Process the Source into a Transformer
Object.  The Source is an XSLT document that
conforms to 
XSL Transformations (XSLT) Version 1.0.  Care must
be taken not to use this Transformer in multiple
Threads running concurrently.
Different TransformerFactories can be used concurrently by
different Threads.


Params:
Throws:
See Also:
Returns:A Transformer object that may be used to perform
  a transformation in a single Thread, never
  null.
/**
     * <p>Process the <code>Source</code> into a <code>Transformer</code>
     * <code>Object</code>.  The <code>Source</code> is an XSLT document that
     * conforms to <a href="http://www.w3.org/TR/xslt">
     * XSL Transformations (XSLT) Version 1.0</a>.  Care must
     * be taken not to use this <code>Transformer</code> in multiple
     * <code>Thread</code>s running concurrently.
     * Different <code>TransformerFactories</code> can be used concurrently by
     * different <code>Thread</code>s.</p>
     *
     * @param source <code>Source </code> of XSLT document used to create
     *   <code>Transformer</code>.
     *   Examples of XML <code>Source</code>s include
     *   {@link javax.xml.transform.stream.StreamSource StreamSource},
     *   {@link javax.xml.transform.sax.SAXSource SAXSource},
     *   {@link javax.xml.transform.dom.DOMSource DOMSource} and
     *   {@link javax.xml.transform.stax.StAXSource StAXSource}.
     *
     * @return A <code>Transformer</code> object that may be used to perform
     *   a transformation in a single <code>Thread</code>, never
     *   <code>null</code>.
     *
     * @throws TransformerConfigurationException Thrown if there are errors when
     *    parsing the <code>Source</code> or it is not possible to create a
     *   <code>Transformer</code> instance.
     * 
     * @see <a href="http://www.w3.org/TR/xslt">
     *   XSL Transformations (XSLT) Version 1.0</a>
     */
    public abstract Transformer newTransformer(Source source)
        throws TransformerConfigurationException;

    
Create a new Transformer that performs a copy
of the Source to the Result.
i.e. the "identity transform".


Throws:
Returns:A Transformer object that may be used to perform a transformation
in a single thread, never null.
/**
     * <p>Create a new <code>Transformer</code> that performs a copy
     * of the <code>Source</code> to the <code>Result</code>.
     * i.e. the "<em>identity transform</em>".</p>
     *
     * @return A Transformer object that may be used to perform a transformation
     * in a single thread, never null.
     *
     * @exception TransformerConfigurationException Thrown if it is not
     *   possible to create a <code>Transformer</code> instance.
     */
    public abstract Transformer newTransformer()
        throws TransformerConfigurationException;

    
Process the Source into a Templates object, which is a
a compiled representation of the source. This Templates object
may then be used concurrently across multiple threads.  Creating
a Templates object allows the TransformerFactory to do detailed
performance optimization of transformation instructions, without
penalizing runtime transformation.

Params:
  • source – An object that holds a URL, input stream, etc.
Throws:
Returns:A Templates object capable of being used for transformation
purposes, never null.
/**
     * Process the Source into a Templates object, which is a
     * a compiled representation of the source. This Templates object
     * may then be used concurrently across multiple threads.  Creating
     * a Templates object allows the TransformerFactory to do detailed
     * performance optimization of transformation instructions, without
     * penalizing runtime transformation.
     *
     * @param source An object that holds a URL, input stream, etc.
     *
     * @return A Templates object capable of being used for transformation
     * purposes, never null.
     *
     * @exception TransformerConfigurationException May throw this during the
     * parse when it is constructing the Templates object and fails.
     */
    public abstract Templates newTemplates(Source source)
        throws TransformerConfigurationException;

    
Get the stylesheet specification(s) associated with the
XML Source document via the

xml-stylesheet processing instruction that match the given criteria.
Note that it is possible to return several stylesheets, in which case
they are applied as if they were a list of imports or cascades in a
single stylesheet.


Params:
  • source – The XML source document.
  • media – The media attribute to be matched.  May be null, in which
     case the preferred templates will be used (i.e. alternate = no).
  • title – The value of the title attribute to match.  May be null.
  • charset – The value of the charset attribute to match.  May be null.
Throws:
See Also:
Returns:A Source Object suitable for passing
  to the TransformerFactory.
/**
     * <p>Get the stylesheet specification(s) associated with the
     * XML <code>Source</code> document via the
     * <a href="http://www.w3.org/TR/xml-stylesheet/">
     * xml-stylesheet processing instruction</a> that match the given criteria.
     * Note that it is possible to return several stylesheets, in which case
     * they are applied as if they were a list of imports or cascades in a
     * single stylesheet.</p>
     *
     * @param source The XML source document.
     * @param media The media attribute to be matched.  May be null, in which
     *      case the preferred templates will be used (i.e. alternate = no).
     * @param title The value of the title attribute to match.  May be null.
     * @param charset The value of the charset attribute to match.  May be null.
     *
     * @return A <code>Source</code> <code>Object</code> suitable for passing
     *   to the <code>TransformerFactory</code>.
     * 
     * @throws TransformerConfigurationException An <code>Exception</code>
     *   is thrown if an error occurs during parsing of the
     *   <code>source</code>.
     * 
     * @see <a href="http://www.w3.org/TR/xml-stylesheet/">
     *   Associating Style Sheets with XML documents Version 1.0</a>
     */
    public abstract Source getAssociatedStylesheet(
        Source source,
        String media,
        String title,
        String charset)
        throws TransformerConfigurationException;

    
Set an object that is used by default during the transformation
to resolve URIs used in document(), xsl:import, or xsl:include.

Params:
  • resolver – An object that implements the URIResolver interface,
or null.
/**
     * Set an object that is used by default during the transformation
     * to resolve URIs used in document(), xsl:import, or xsl:include.
     *
     * @param resolver An object that implements the URIResolver interface,
     * or null.
     */
    public abstract void setURIResolver(URIResolver resolver);

    
Get the object that is used by default during the transformation
to resolve URIs used in document(), xsl:import, or xsl:include.

Returns:The URIResolver that was set with setURIResolver.
/**
     * Get the object that is used by default during the transformation
     * to resolve URIs used in document(), xsl:import, or xsl:include.
     *
     * @return The URIResolver that was set with setURIResolver.
     */
    public abstract URIResolver getURIResolver();

    //======= CONFIGURATION METHODS =======

	
Set a feature for this TransformerFactory and Transformers
or Templates created by this factory.


 Feature names are fully qualified URIs. Implementations may define their own features. An TransformerConfigurationException is thrown if this TransformerFactory or the
Transformers or Templates it creates cannot support the feature.
It is possible for an TransformerFactory to expose a feature value but be unable to change its state.



All implementations are required to support the XMLConstants.FEATURE_SECURE_PROCESSING feature. When the feature is:


    
  
  • 
    true: the implementation will limit XML processing to conform to implementation limits and behave in a secure fashion as defined by the implementation. Examples include resolving user defined style sheets and functions. If XML processing is limited for security reasons, it will be reported via a call to the registered ErrorListener.fatalError(TransformerException exception). See setErrorListener(ErrorListener listener). 
    • 
  
  • 
    false: the implementation will processing XML according to the XML specifications without
    regard to possible implementation limits.
  
    • 



Params:
  • name – Feature name.
  • value – Is feature state true or false.
Throws:
/**
	 * <p>Set a feature for this <code>TransformerFactory</code> and <code>Transformer</code>s
	 * or <code>Template</code>s created by this factory.</p>
	 * 
	 * <p>
	 * Feature names are fully qualified {@link java.net.URI}s.
	 * Implementations may define their own features.
	 * An {@link TransformerConfigurationException} is thrown if this <code>TransformerFactory</code> or the
	 * <code>Transformer</code>s or <code>Template</code>s it creates cannot support the feature.
	 * It is possible for an <code>TransformerFactory</code> to expose a feature value but be unable to change its state.
	 * </p>
	 * 
	 * <p>All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature.
	 * When the feature is:</p>
	 * <ul>
	 *   <li>
	 *     <code>true</code>: the implementation will limit XML processing to conform to implementation limits
	 *     and behave in a secure fashion as defined by the implementation.
	 *     Examples include resolving user defined style sheets and functions.
	 *     If XML processing is limited for security reasons, it will be reported via a call to the registered
	 *     {@link ErrorListener#fatalError(TransformerException exception)}.
	 *     See {@link  #setErrorListener(ErrorListener listener)}.
	 *   </li>
	 *   <li>
	 *     <code>false</code>: the implementation will processing XML according to the XML specifications without
	 *     regard to possible implementation limits.
	 *   </li>
	 * </ul>
	 * 
	 * @param name Feature name.
	 * @param value Is feature state <code>true</code> or <code>false</code>.
	 *  
	 * @throws TransformerConfigurationException if this <code>TransformerFactory</code>
	 *   or the <code>Transformer</code>s or <code>Template</code>s it creates cannot support this feature.
     * @throws NullPointerException If the <code>name</code> parameter is null.
	 */
	public abstract void setFeature(String name, boolean value)
		throws TransformerConfigurationException;

    
Look up the value of a feature.

 Feature names are fully qualified URIs. Implementations may define their own features. false is returned if this TransformerFactory or the
Transformers or Templates it creates cannot support the feature.
It is possible for an TransformerFactory to expose a feature value but be unable to change its state.



Params:
  • name – Feature name.
Throws:
Returns:The current state of the feature, true or false.
/**
     * Look up the value of a feature.
     *
	 * <p>
	 * Feature names are fully qualified {@link java.net.URI}s.
	 * Implementations may define their own features.
	 * <code>false</code> is returned if this <code>TransformerFactory</code> or the
	 * <code>Transformer</code>s or <code>Template</code>s it creates cannot support the feature.
	 * It is possible for an <code>TransformerFactory</code> to expose a feature value but be unable to change its state.
	 * </p>
	 * 
	 * @param name Feature name.
	 * 
     * @return The current state of the feature, <code>true</code> or <code>false</code>.
     * 
     * @throws NullPointerException If the <code>name</code> parameter is null.
     */
    public abstract boolean getFeature(String name);

    
Allows the user to set specific attributes on the underlying
implementation.  An attribute in this context is defined to
be an option that the implementation provides.
An IllegalArgumentException is thrown if the underlying
implementation doesn't recognize the attribute.

Params:
  • name – The name of the attribute.
  • value – The value of the attribute.
/**
     * Allows the user to set specific attributes on the underlying
     * implementation.  An attribute in this context is defined to
     * be an option that the implementation provides.
     * An <code>IllegalArgumentException</code> is thrown if the underlying
     * implementation doesn't recognize the attribute.
     *
     * @param name The name of the attribute.
     * @param value The value of the attribute.
     */
    public abstract void setAttribute(String name, Object value);

    
Allows the user to retrieve specific attributes on the underlying
implementation.
An IllegalArgumentException is thrown if the underlying
implementation doesn't recognize the attribute.

Params:
  • name – The name of the attribute.
Returns:value The value of the attribute.
/**
     * Allows the user to retrieve specific attributes on the underlying
     * implementation.
     * An <code>IllegalArgumentException</code> is thrown if the underlying
     * implementation doesn't recognize the attribute.
     * 
     * @param name The name of the attribute.
     * @return value The value of the attribute.
     */
    public abstract Object getAttribute(String name);

    
Set the error event listener for the TransformerFactory, which
is used for the processing of transformation instructions,
and not for the transformation itself.
An IllegalArgumentException is thrown if the
ErrorListener listener is null.

Params:
  • listener – The new error listener.
/**
     * Set the error event listener for the TransformerFactory, which
     * is used for the processing of transformation instructions,
     * and not for the transformation itself.
     * An <code>IllegalArgumentException</code> is thrown if the
     * <code>ErrorListener</code> listener is <code>null</code>.
     *
     * @param listener The new error listener.
     */
    public abstract void setErrorListener(ErrorListener listener);

    
Get the error event handler for the TransformerFactory.

Returns:The current error handler, which should never be null.
/**
     * Get the error event handler for the TransformerFactory.
     *
     * @return The current error handler, which should never be null.
     */
    public abstract ErrorListener getErrorListener();

}