org.mule.module.xml.transformer

Class XsltTransformer

java.lang.Object

org.mule.transformer.AbstractTransformer

org.mule.module.xml.transformer.AbstractXmlTransformer

org.mule.module.xml.transformer.XsltTransformer

All Implemented Interfaces:

Initialisable, NamedObject, BaseTransformer, Transformer

public class XsltTransformer
extends AbstractXmlTransformer

XsltTransformer performs an XSLT transform on a DOM (or other XML-ish) object.

This transformer maintains a pool of javax.xml.Transformer objects to speed up processing of concurrent requests. The pool can be configured using #setMaxIdleTransformers() and #setMaxIdleTransformers().

Parameter can also be set as part of the transformation context and these can be mapped to conent in the current message using property extractors or can be fixed values.

For example, the current event's message has a property named "myproperty", also you want to generate a uuid as a parameter. To do this you can define context properties that can provide an expression to be evaluated on the current message.

Example Configuration:

  <mxml:xslt-transformer name="MyXsltTransformer" xslFile="myXslFile.xsl"&gt
      <context-property name="myParameter" value="${head:myproperty}"/&gt
      <context-property name="myParameter2" value="${function:uuid}"/&gt
  </mxml:xslt-transformer&gt
 

The 'header' expression pulls a header from the current message and 'function' can execute a set of arbitrary functions. You can also pass in static values by ommitting the expression prefix '${'.

In addition to being able to pass in an XSLT file you can also define templates inline. For example -

  <mxml:xslt-transformer name="MyXsltTransformer"&gt
      <mxml:xslt-text&gt
          
 

                
 

               
                   
                       
                   
               
           
  </mxml:xslt-text&gt
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	XsltTransformer.DefaultErrorListener
protected class	XsltTransformer.PooledXsltTransformerFactory

Nested classes/interfaces inherited from class org.mule.module.xml.transformer.AbstractXmlTransformer

AbstractXmlTransformer.ResultHolder

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.commons.pool.impl.GenericObjectPool	transformerPool

Fields inherited from class org.mule.transformer.AbstractTransformer

DEFAULT_TRUNCATE_LENGTH, endpoint, logger, name, returnClass, sourceTypes

Fields inherited from interface org.mule.api.lifecycle.Initialisable

PHASE_NAME

Constructor Summary

Constructors

Constructor and Description
XsltTransformer()

Method Summary

Methods

Modifier and Type	Method and Description
Object	doTransform(Object src, String encoding) Transform, using XSLT, a XML String to another String.
protected void	doTransform(String encoding, Source sourceDoc, Result result)
protected Object	evaluateTransformParameter(String name, Object value) Returns the value to be set for the parameter.
Map	getContextProperties() Gets the parameters to be used when applying the transformation
protected Object	getDelayedResult(String encoding, Source sourceDoc)
int	getMaxActiveTransformers()
int	getMaxIdleTransformers()
protected StreamSource	getStreamSource() Returns the StreamSource corresponding to xslFile
URIResolver	getUriResolver()
String	getXslFile()
String	getXslt()
String	getXslTransformerFactory() Returns the name of the currently configured javax.xml.transform.Transformer factory class used to create XSLT Transformers.
void	initialise() Template method where deriving classes can do any initialisation after the properties have been set on this transformer
void	setContextProperties(Map contextProperties) Sets the parameters to be used when applying the transformation
void	setMaxActiveTransformers(int maxActiveTransformers) Sets the the current maximum number of active transformer objects allowed in the pool
void	setMaxIdleTransformers(int maxIdleTransformers) Sets the the current maximum number of idle transformer objects allowed in the pool
void	setUriResolver(URIResolver uriResolver)
void	setXslFile(String xslFile)
void	setXslt(String xslt)
void	setXslTransformerFactory(String xslTransformerFactory) Configures the javax.xml.transform.Transformer factory class

Methods inherited from class org.mule.module.xml.transformer.AbstractXmlTransformer

convertToBytes, convertToText, convertToText, getOutputEncoding, getResultHolder, getXMLInputFactory, getXMLOutputFactory, isUseStaxSource, setOutputEncoding, setUseStaxSource, setXMLInputFactory, setXMLOutputFactory, writeToStream

Methods inherited from class org.mule.transformer.AbstractTransformer

checkReturnClass, generateTransformerName, getEndpoint, getName, getReturnClass, getSourceTypes, isAcceptNull, isConsumed, isIgnoreBadInput, isSourceTypeSupported, isSourceTypeSupported, registerSourceType, setEndpoint, setIgnoreBadInput, setName, setReturnClass, toString, transform, unregisterSourceType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

transformerPool

protected final org.apache.commons.pool.impl.GenericObjectPool transformerPool

Constructor Detail

XsltTransformer

public XsltTransformer()

Method Detail

initialise

public void initialise()
                throws InitialisationException

Description copied from class: AbstractTransformer

Template method where deriving classes can do any initialisation after the properties have been set on this transformer

Specified by:

initialise in interface Initialisable

Overrides:

initialise in class AbstractTransformer

Throws:

InitialisationException - if a fatal error occurs causing the Mule instance to shutdown

RecoverableException - if an error occurs that can be recovered from

doTransform

public Object doTransform(Object src,
                 String encoding)
                   throws TransformerException

Transform, using XSLT, a XML String to another String.

Specified by:

doTransform in class AbstractTransformer

Parameters:

src - The source XML (String, byte[], DOM, etc.)

Returns:

The result in the type specified by the user

Throws:

TransformerException

getDelayedResult

protected Object getDelayedResult(String encoding,
                      Source sourceDoc)

doTransform

protected void doTransform(String encoding,
               Source sourceDoc,
               Result result)
                    throws Exception

Throws:

Exception

getXslTransformerFactory

public String getXslTransformerFactory()

Returns the name of the currently configured javax.xml.transform.Transformer factory class used to create XSLT Transformers.

Returns:

a TransformerFactory class name or null if none has been configured

setXslTransformerFactory

public void setXslTransformerFactory(String xslTransformerFactory)

Configures the javax.xml.transform.Transformer factory class

Parameters:

xslTransformerFactory - the name of the TransformerFactory class to use

getXslFile

public String getXslFile()

Returns:

Returns the xslFile.

setXslFile

public void setXslFile(String xslFile)

Parameters:

xslFile - The xslFile to set.

getXslt

public String getXslt()

setXslt

public void setXslt(String xslt)

getUriResolver

public URIResolver getUriResolver()

setUriResolver

public void setUriResolver(URIResolver uriResolver)

getStreamSource

protected StreamSource getStreamSource()
                                throws InitialisationException

Returns the StreamSource corresponding to xslFile

Returns:

The StreamSource

Throws:

InitialisationException

getMaxActiveTransformers

public int getMaxActiveTransformers()

Returns:

The current maximum number of allowable active transformer objects in the pool

setMaxActiveTransformers

public void setMaxActiveTransformers(int maxActiveTransformers)

Sets the the current maximum number of active transformer objects allowed in the pool

Parameters:

maxActiveTransformers - New maximum size to set

getMaxIdleTransformers

public int getMaxIdleTransformers()

Returns:

The current maximum number of allowable idle transformer objects in the pool

setMaxIdleTransformers

public void setMaxIdleTransformers(int maxIdleTransformers)

Sets the the current maximum number of idle transformer objects allowed in the pool

Parameters:

maxIdleTransformers - New maximum size to set

getContextProperties

public Map getContextProperties()

Gets the parameters to be used when applying the transformation

Returns:

a map of the parameter names and associated values

See Also:

Transformer.setParameter(java.lang.String, java.lang.Object)

setContextProperties

public void setContextProperties(Map contextProperties)

Sets the parameters to be used when applying the transformation

Parameters:

contextProperties - a map of the parameter names and associated values

See Also:

Transformer.setParameter(java.lang.String, java.lang.Object)

evaluateTransformParameter

protected Object evaluateTransformParameter(String name,
                                Object value)
                                     throws TransformerException

Returns the value to be set for the parameter. This method is called for each parameter before it is set on the transformer. The purpose of this method is to allow dynamic parameters related to the event (usually message properties) to be used. Any attribute of the current MuleEvent can be accessed using Property Extractors such as JXpath, bean path or header retrieval.

Parameters:

name - the name of the parameter. The name isn't used for this implementation but is exposed as a param for classes that may need it.

value - the value of the paramter

Returns:

the object to be set as the parameter value

Throws:

TransformerException