The FastXSLT Mediator is similar to the XSLT mediator, but it uses the Streaming XPath Parser and applies the XSLT transformation to the message stream instead of to the XML message payload. The result is a faster transformation, but you cannot specify the source, properties, features, or resources as you can with the XSLT mediator.
To enable the FastXSLT mediator, your XSLT script must include the following parameter in the XSL output:
omit-xml-declaration="yes"For example:
<xsl:output method="xml" omit-xml-declaration="yes" encoding="UTF-8" indent="yes"/>
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