This package implements SAX2-specific transformation APIs. It provides
classes which allow input from ContentHandler
events, and also classes that produce org.xml.sax.ContentHandler events. It
also provides methods to set the input source as an
XMLReader, or to use a
InputSource as the source. It also allows the
creation of a XMLFilter, which enables
transformations to "pull" from other transformations, and lets the transformer
to be used polymorphically as an XMLReader.
The SAXSource class allows the
setting of an XMLReader to be used for "pulling"
parse events, and an InputSource that may be used to
specify the SAX source.
The SAXResult class allows the
setting of a ContentHandler to be the receiver of
SAX2 events from the transformation.
The SAXTransformerFactory extends
TransformerFactory to provide factory
methods for creating TemplatesHandler,
TransformerHandler, and
XMLReader instances.
To obtain a SAXTransformerFactory,
the caller must cast the TransformerFactory
instance returned from
newInstance().
The TransformerHandler interface
allows a transformation to be created from SAX2 parse events, which is a "push"
model rather than the "pull" model that normally occurs for a transformation.
Normal parse events are received through the
ContentHandler interface, lexical events such as
startCDATA and endCDATA are received through the
LexicalHandler interface, and events that signal
the start or end of disabling output escaping are received via
processingInstruction(String, String), with the
target parameter being
PI_DISABLE_OUTPUT_ESCAPING and
PI_ENABLE_OUTPUT_ESCAPING. If
parameters, output properties, or other features need to be set on the
Transformer handler, a Transformer reference
will need to be obtained from
getTransformer(), and
the methods invoked from that reference.
The TemplatesHandler interface
allows the creation of Templates objects
from SAX2 parse events. Once the ContentHandler
events are complete, the Templates object may be obtained from
getTemplates(). Note that
setSystemId(String) should
normally be called in order to establish a base system ID from which relative
URLs may be resolved.
The
newXMLFilter(Source)
method allows the creation of a XMLFilter, which
encapsulates the SAX2 notion of a "pull" transformation. The following
illustrates several transformations chained together. Each filter points to a
parent XMLReader, and the final transformation is
caused by invoking parse(String) on the final
reader in the chain.
