javax.xml.transform

Class TransformerFactory

Known Direct Subclasses:
SAXTransformerFactory

public abstract class TransformerFactory
extends java.lang.Object

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

Constructor Summary

TransformerFactory()
Default constructor is protected on purpose.

Method Summary

abstract Source
getAssociatedStylesheet(Source source, String media, String title, String charset)
Get the stylesheet specification(s) associated with the XML Source document via the xml-stylesheet processing instruction that match the given criteria.
abstract Object
getAttribute(String name)
Allows the user to retrieve specific attributes on the underlying implementation.
abstract ErrorListener
getErrorListener()
Get the error event handler for the TransformerFactory.
abstract boolean
getFeature(String name)
Look up the value of a feature.
abstract URIResolver
getURIResolver()
Get the object that is used by default during the transformation to resolve URIs used in document(), xsl:import, or xsl:include.
static TransformerFactory
newInstance()
Obtain a new instance of a TransformerFactory.
abstract Templates
newTemplates(Source source)
Process the Source into a Templates object, which is a a compiled representation of the source.
abstract Transformer
newTransformer()
Create a new Transformer that performs a copy of the Source to the Result.
abstract Transformer
newTransformer(Source source)
Process the Source into a Transformer Object.
abstract void
setAttribute(String name, Object value)
Allows the user to set specific attributes on the underlying implementation.
abstract void
setErrorListener(ErrorListener listener)
Set the error event listener for the TransformerFactory, which is used for the processing of transformation instructions, and not for the transformation itself.
abstract void
setFeature(String name, boolean value)
Set a feature for this TransformerFactory and Transformers or Templates created by this factory.
abstract void
setURIResolver(URIResolver resolver)
Set an object that is used by default during the transformation to resolve URIs used in document(), xsl:import, or xsl:include.

Constructor Details

TransformerFactory

protected TransformerFactory()
Default constructor is protected on purpose.

Method Details

getAssociatedStylesheet

public abstract Source getAssociatedStylesheet(Source source,
                                               String media,
                                               String title,
                                               String charset)
            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.
Parameters:
source - The XML source document.
media - The media attribute to be matched. May be null, in which case the prefered 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.
Returns:
A Source Object suitable for passing to the TransformerFactory.
Throws:
TransformerConfigurationException - An Exception is thrown if an error occurings during parsing of the source.

getAttribute

public abstract Object getAttribute(String name)
Allows the user to retrieve specific attributes on the underlying implementation. An IllegalArgumentException is thrown if the underlying implementation doesn't recognize the attribute.
Parameters:
name - The name of the attribute.
Returns:
value The value of the attribute.

getErrorListener

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

getFeature

public abstract boolean getFeature(String name)
Look up the value of a feature.

Feature names are fully qualified java.net.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.

Parameters:
name - Feature name.
Returns:
The current state of the feature, true or false.

getURIResolver

public abstract URIResolver getURIResolver()
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.

newInstance

public static TransformerFactory newInstance()
            throws TransformerFactoryConfigurationError
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.
Returns:
new TransformerFactory instance, never null.
Throws:
TransformerFactoryConfigurationError - Thrown if the implementation is not available or cannot be instantiated.

newTemplates

public abstract Templates newTemplates(Source source)
            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.
Parameters:
source - An object that holds a URL, input stream, etc.
Returns:
A Templates object capable of being used for transformation purposes, never null.
Throws:
TransformerConfigurationException - May throw this during the parse when it is constructing the Templates object and fails.

newTransformer

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

newTransformer

public abstract Transformer newTransformer(Source source)
            throws TransformerConfigurationException
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.
Parameters:
source - Source of XSLT document used to create Transformer. Examples of XML Sources include DOMSource, SAXSource, and StreamSource.
Returns:
A Transformer object that may be used to perform a transformation in a single Thread, never null.
Throws:
TransformerConfigurationException - Thrown if there are errors when parsing the Source or it is not possible to create a Transformer instance.

setAttribute

public abstract void setAttribute(String name,
                                  Object value)
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.
Parameters:
name - The name of the attribute.
value - The value of the attribute.

setErrorListener

public abstract void setErrorListener(ErrorListener 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 IllegalArgumentException is thrown if the ErrorListener listener is null.
Parameters:
listener - The new error listener.

setFeature

public abstract void setFeature(String name,
                                boolean value)
            throws TransformerConfigurationException
Set a feature for this TransformerFactory and Transformers or Templates created by this factory.

Feature names are fully qualified java.net.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.
Parameters:
name - Feature name.
value - Is feature state true or false.
Throws:
TransformerConfigurationException - if this TransformerFactory or the Transformers or Templates it creates cannot support this feature.

setURIResolver

public abstract void setURIResolver(URIResolver resolver)
Set an object that is used by default during the transformation to resolve URIs used in document(), xsl:import, or xsl:include.
Parameters:
resolver - An object that implements the URIResolver interface, or null.