FileDocCategorySizeDatePackage
Transformer.javaAPI DocJava SE 6 API14377Tue Jun 10 00:27:12 BST 2008javax.xml.transform

Transformer

public abstract class Transformer extends Object
An instance of this abstract class can transform a source tree into a result tree.

An instance of this class can be obtained with the {@link TransformerFactory#newTransformer TransformerFactory.newTransformer} method. This instance may then be used to process XML from a variety of sources and write the transformation output to a variety of sinks.

An object of this class may not be used in multiple threads running concurrently. Different Transformers may be used concurrently by different threads.

A Transformer may be used multiple times. Parameters and output properties are preserved across transformations.

author
Jeff Suttor
version
$Revision: 1.3 $, $Date: 2005/10/12 17:14:20 $

Fields Summary
Constructors Summary
protected Transformer()
Default constructor is protected on purpose.

 
Methods Summary
public abstract voidclearParameters()
Clear all parameters set with setParameter.

public abstract javax.xml.transform.ErrorListenergetErrorListener()
Get the error event handler in effect for the transformation. Implementations must provide a default error listener.

return
The current error handler, which should never be null.

public abstract java.util.PropertiesgetOutputProperties()

Get a copy of the output properties for the transformation.

The properties returned should contain properties set by the user, and properties set by the stylesheet, and these properties are "defaulted" by default properties specified by section 16 of the XSL Transformations (XSLT) W3C Recommendation. The properties that were specifically set by the user or the stylesheet should be in the base Properties list, while the XSLT default properties that were not specifically set should be the default Properties list. Thus, getOutputProperties().getProperty(String key) will obtain any property in that was set by {@link #setOutputProperty}, {@link #setOutputProperties}, in the stylesheet, or the default properties, while getOutputProperties().get(String key) will only retrieve properties that were explicitly set by {@link #setOutputProperty}, {@link #setOutputProperties}, or in the stylesheet.

Note that mutation of the Properties object returned will not effect the properties that the transformer contains.

If any of the argument keys are not recognized and are not namespace qualified, the property will be ignored and not returned. In other words the behaviour is not orthogonal with {@link #setOutputProperties setOutputProperties}.

return
A copy of the set of output properties in effect for the next transformation.
see
javax.xml.transform.OutputKeys
see
java.util.Properties
see
XSL Transformations (XSLT) Version 1.0

public abstract java.lang.StringgetOutputProperty(java.lang.String name)

Get an output property that is in effect for the transformer.

If a property has been set using {@link #setOutputProperty}, that value will be returned. Otherwise, if a property is explicitly specified in the stylesheet, that value will be returned. If the value of the property has been defaulted, that is, if no value has been set explicitly either with {@link #setOutputProperty} or in the stylesheet, the result may vary depending on implementation and input stylesheet.

param
name A non-null String that specifies an output property name, which may be namespace qualified.
return
The string value of the output property, or null if no property was found.
throws
IllegalArgumentException If the property is not supported.
see
javax.xml.transform.OutputKeys

public abstract java.lang.ObjectgetParameter(java.lang.String name)
Get a parameter that was explicitly set with setParameter.

This method does not return a default parameter value, which cannot be determined until the node context is evaluated during the transformation process.

param
name of Object to get
return
A parameter that has been set with setParameter.

public abstract javax.xml.transform.URIResolvergetURIResolver()
Get an object that will be used to resolve URIs used in document().

return
An object that implements the URIResolver interface, or null.

public voidreset()

Reset this Transformer to its original configuration.

Transformer is reset to the same state as when it was created with {@link TransformerFactory#newTransformer()}, {@link TransformerFactory#newTransformer(Source source)} or {@link Templates#newTransformer()}. reset() is designed to allow the reuse of existing Transformers thus saving resources associated with the creation of new Transformers.

The reset Transformer is not guaranteed to have the same {@link URIResolver} or {@link ErrorListener} Objects, e.g. {@link Object#equals(Object obj)}. It is guaranteed to have a functionally equal URIResolver and ErrorListener.

throws
UnsupportedOperationException When implementation does not override this method.
since
1.5


		// implementors should override this method
		throw new UnsupportedOperationException(
			"This Transformer, \"" + this.getClass().getName() + "\", does not support the reset functionality."
			+ "  Specification \"" + this.getClass().getPackage().getSpecificationTitle() + "\""
			+ " version \"" + this.getClass().getPackage().getSpecificationVersion() + "\""
			);
	
public abstract voidsetErrorListener(javax.xml.transform.ErrorListener listener)
Set the error event listener in effect for the transformation.

param
listener The new error listener.
throws
IllegalArgumentException if listener is null.

public abstract voidsetOutputProperties(java.util.Properties oformat)
Set the output properties for the transformation. These properties will override properties set in the Templates with xsl:output.

If argument to this function is null, any properties previously set are removed, and the value will revert to the value defined in the templates object.

Pass a qualified property key name as a two-part string, the namespace URI enclosed in curly braces ({}), followed by the local name. If the name has a null URL, the String only contain the local name. An application can safely check for a non-null URI by testing to see if the first character of the name is a '{' character.

For example, if a URI and local name were obtained from an element defined with <xyz:foo xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>, then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo". Note that no prefix is used.

An IllegalArgumentException is thrown if any of the argument keys are not recognized and are not namespace qualified.

param
oformat A set of output properties that will be used to override any of the same properties in affect for the transformation.
throws
IllegalArgumentException When keys are not recognized and are not namespace qualified.
see
javax.xml.transform.OutputKeys
see
java.util.Properties

public abstract voidsetOutputProperty(java.lang.String name, java.lang.String value)
Set an output property that will be in effect for the transformation.

Pass a qualified property name as a two-part string, the namespace URI enclosed in curly braces ({}), followed by the local name. If the name has a null URL, the String only contain the local name. An application can safely check for a non-null URI by testing to see if the first character of the name is a '{' character.

For example, if a URI and local name were obtained from an element defined with <xyz:foo xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>, then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo". Note that no prefix is used.

The Properties object that was passed to {@link #setOutputProperties} won't be effected by calling this method.

param
name A non-null String that specifies an output property name, which may be namespace qualified.
param
value The non-null string value of the output property.
throws
IllegalArgumentException If the property is not supported, and is not qualified with a namespace.
see
javax.xml.transform.OutputKeys

public abstract voidsetParameter(java.lang.String name, java.lang.Object value)
Add a parameter for the transformation.

Pass a qualified name as a two-part string, the namespace URI enclosed in curly braces ({}), followed by the local name. If the name has a null URL, the String only contain the local name. An application can safely check for a non-null URI by testing to see if the first character of the name is a '{' character.

For example, if a URI and local name were obtained from an element defined with <xyz:foo xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>, then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo". Note that no prefix is used.

param
name The name of the parameter, which may begin with a namespace URI in curly braces ({}).
param
value The value object. This can be any valid Java object. It is up to the processor to provide the proper object coersion or to simply pass the object on for use in an extension.
throws
NullPointerException If value is null.

public abstract voidsetURIResolver(javax.xml.transform.URIResolver resolver)
Set an object that will be used to resolve URIs used in document().

If the resolver argument is null, the URIResolver value will be cleared and the transformer will no longer have a resolver.

param
resolver An object that implements the URIResolver interface, or null.

public abstract voidtransform(javax.xml.transform.Source xmlSource, javax.xml.transform.Result outputTarget)

Transform the XML Source to a Result. Specific transformation behavior is determined by the settings of the TransformerFactory in effect when the Transformer was instantiated and any modifications made to the Transformer instance.

An empty Source is represented as an empty document as constructed by {@link javax.xml.parsers.DocumentBuilder#newDocument()}. The result of transforming an empty Source depends on the transformation behavior; it is not always an empty Result.

param
xmlSource The XML input to transform.
param
outputTarget The Result of transforming the xmlSource.
throws
TransformerException If an unrecoverable error occurs during the course of the transformation.