public abstract class

Transformer

extends Object
java.lang.Object
   ↳ javax.xml.transform.Transformer

Class Overview

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 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.

Summary

Protected Constructors
Transformer()
Default constructor is protected on purpose.
Public Methods
abstract void clearParameters()
Clear all parameters set with setParameter.
abstract ErrorListener getErrorListener()
Get the error event handler in effect for the transformation.
abstract Properties getOutputProperties()

Get a copy of the output properties for the transformation.

abstract String getOutputProperty(String name)
Get an output property that is in effect for the transformer.
abstract Object getParameter(String name)
Get a parameter that was explicitly set with setParameter.
abstract URIResolver getURIResolver()
Get an object that will be used to resolve URIs used in document().
void reset()

Reset this Transformer to its original configuration.

abstract void setErrorListener(ErrorListener listener)
Set the error event listener in effect for the transformation.
abstract void setOutputProperties(Properties oformat)
Set the output properties for the transformation.
abstract void setOutputProperty(String name, String value)
Set an output property that will be in effect for the transformation.
abstract void setParameter(String name, Object value)
Add a parameter for the transformation.
abstract void setURIResolver(URIResolver resolver)
Set an object that will be used to resolve URIs used in document().
abstract void transform(Source xmlSource, Result outputTarget)

Transform the XML Source to a Result.

[Expand]
Inherited Methods
From class java.lang.Object

Protected Constructors

protected Transformer ()

Since: API Level 8

Default constructor is protected on purpose.

Public Methods

public abstract void clearParameters ()

Since: API Level 8

Clear all parameters set with setParameter.

public abstract ErrorListener getErrorListener ()

Since: API Level 8

Get the error event handler in effect for the transformation. Implementations must provide a default error listener.

Returns
  • The current error handler, which should never be null.

public abstract Properties getOutputProperties ()

Since: API Level 8

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 setOutputProperty(String, String), setOutputProperties(Properties), in the stylesheet, or the default properties, while getOutputProperties().get(String key) will only retrieve properties that were explicitly set by setOutputProperty(String, String), setOutputProperties(Properties), 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 behavior is not orthogonal with setOutputProperties.

Returns
  • A copy of the set of output properties in effect for the next transformation.

public abstract String getOutputProperty (String name)

Since: API Level 8

Get an output property that is in effect for the transformer. The property specified may be a property that was set with setOutputProperty, or it may be a property specified in the stylesheet.

Parameters
name A non-null String that specifies an output property name, which may be namespace qualified.
Returns
  • The string value of the output property, or null if no property was found.
Throws
IllegalArgumentException If the property is not supported.
See Also

public abstract Object getParameter (String name)

Since: API Level 8

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.

Parameters
name of Object to get
Returns
  • A parameter that has been set with setParameter.

public abstract URIResolver getURIResolver ()

Since: API Level 8

Get an object that will be used to resolve URIs used in document().

Returns
  • An object that implements the URIResolver interface, or null.

public void reset ()

Since: API Level 8

Reset this Transformer to its original configuration.

Transformer is reset to the same state as when it was created with newTransformer(), newTransformer(Source) or 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 URIResolver or ErrorListener Objects, e.g. equals(Object). It is guaranteed to have a functionally equal URIResolver and ErrorListener.

public abstract void setErrorListener (ErrorListener listener)

Since: API Level 8

Set the error event listener in effect for the transformation.

Parameters
listener The new error listener.
Throws
IllegalArgumentException if listener is null.

public abstract void setOutputProperties (Properties oformat)

Since: API Level 8

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.

Parameters
oformat A set of output properties that will be used to override any of the same properties in affect for the transformation.

public abstract void setOutputProperty (String name, String value)

Since: API Level 8

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 setOutputProperties(Properties) won't be effected by calling this method.

Parameters
name A non-null String that specifies an output property name, which may be namespace qualified.
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 Also

public abstract void setParameter (String name, Object value)

Since: API Level 8

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.

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

public abstract void setURIResolver (URIResolver resolver)

Since: API Level 8

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.

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

public abstract void transform (Source xmlSource, Result outputTarget)

Since: API Level 8

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 newDocument(). The result of transforming an empty Source depends on the transformation behavior; it is not always an empty Result.

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