net.sf.saxon
Class Filter

java.lang.Object
  net.sf.saxon.Filter

All Implemented Interfaces:

XMLFilter, XMLReader

public class Filter
extends Object
implements XMLFilter

Filter is an XMLFilter (a SAX2 filter) that performs a transformation taking a SAX stream as input and producing a SAX stream as output.

Author:

Michael H. Kay

Constructor Summary

protected

Filter(Controller controller) Create a Filter and initialise variables.

Method Summary

ContentHandler	getContentHandler() Get the ContentHandler registered using setContentHandler()
DTDHandler	getDTDHandler() Return the current DTD handler.
EntityResolver	getEntityResolver() Return the current entity resolver.
ErrorHandler	getErrorHandler() Return the current error handler.
boolean	getFeature(String name) Look up the value of a feature.
XMLReader	getParent() Get the parent reader.
Object	getProperty(String name) Look up the value of a property.
Transformer	getTransformer() Get the underlying Transformer.
void	parse(InputSource input) Parse an XML document - In the context of a Transformer, this means perform a transformation.
void	parse(String systemId) Parse (that is, transform) an XML document given a system identifier (URI).
void	setContentHandler(ContentHandler handler) Register a content handler to receive the output of the transformation filter.
void	setDTDHandler(DTDHandler handler) Allow an application to register a DTD event handler.
void	setEntityResolver(EntityResolver resolver) Allow an application to register an entity resolver.
void	setErrorHandler(ErrorHandler handler) Allow an application to register an error event handler.
void	setFeature(String name, boolean value) Set the state of a feature.
void	setParent(XMLReader parent) Set the parent reader.
void	setProperty(String name, Object value) Set the value of a property.

Methods inherited from class java.lang.Object

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

Constructor Detail

Filter

protected Filter(Controller controller)

Create a Filter and initialise variables. The constructor is protected, because the Filter should be created using newXMLFilter() in the SAXTransformerFactory class

Method Detail

setParent

public void setParent(XMLReader parent)

Set the parent reader.

This method allows the application to link the filter to a parent reader (which may be another filter). The argument may not be null.

Specified by:

setParent in interface XMLFilter

Parameters:

parent - The parent reader (the supplier of SAX events).

getParent

public XMLReader getParent()

Get the parent reader.

This method allows the application to query the parent reader (which may be another filter). It is generally a bad idea to perform any operations on the parent reader directly: they should all pass through this filter.

Specified by:

getParent in interface XMLFilter

Returns:

The parent filter, or null if none has been set.

getFeature

public boolean getFeature(String name)
                   throws SAXNotRecognizedException,
                          SAXNotSupportedException

Look up the value of a feature.

The feature name is any fully-qualified URI. It is possible for an XMLReader to recognize a feature name but to be unable to return its value; this is especially true in the case of an adapter for a SAX1 Parser, which has no way of knowing whether the underlying parser is performing validation or expanding external entities.

All XMLReaders are required to recognize the http://xml.org/sax/features/namespaces and the http://xml.org/sax/features/namespace-prefixes feature names.

Specified by:

getFeature in interface XMLReader

Parameters:

name - The feature name, which is a fully-qualified URI.

Returns:

The current state of the feature (true or false).

Throws:

SAXNotRecognizedException - When the XMLReader does not recognize the feature name.

SAXNotSupportedException - When the XMLReader recognizes the feature name but cannot determine its value at this time.

See Also:

setFeature(java.lang.String, boolean)

setFeature

public void setFeature(String name,
                       boolean value)
                throws SAXNotRecognizedException,
                       SAXNotSupportedException

Set the state of a feature.

The feature name is any fully-qualified URI. It is possible for an XMLReader to recognize a feature name but to be unable to set its value

All XMLReaders are required to support setting http://xml.org/sax/features/namespaces to true and http://xml.org/sax/features/namespace-prefixes to false.

Some feature values may be immutable or mutable only in specific contexts, such as before, during, or after a parse.

Specified by:

setFeature in interface XMLReader

Parameters:

name - The feature name, which is a fully-qualified URI.

value - The requested state of the feature (true or false).

Throws:

SAXNotRecognizedException - When the XMLReader does not recognize the feature name.

SAXNotSupportedException - When the XMLReader recognizes the feature name but cannot set the requested value.

See Also:

getFeature(java.lang.String)

getProperty

public Object getProperty(String name)
                   throws SAXNotRecognizedException,
                          SAXNotSupportedException

Look up the value of a property.

The property name is any fully-qualified URI. It is possible for an XMLReader to recognize a property name but to be unable to return its state.

XMLReaders are not required to recognize any specific property names, though an initial core set is documented for SAX2.

Some property values may be available only in specific contexts, such as before, during, or after a parse.

Implementors are free (and encouraged) to invent their own properties, using names built on their own URIs.

Specified by:

getProperty in interface XMLReader

Parameters:

name - The property name, which is a fully-qualified URI.

Returns:

The current value of the property.

Throws:

SAXNotRecognizedException - When the XMLReader does not recognize the property name.

SAXNotSupportedException - When the XMLReader recognizes the property name but cannot determine its value at this time.

See Also:

setProperty(java.lang.String, java.lang.Object)

setProperty

public void setProperty(String name,
                        Object value)
                 throws SAXNotRecognizedException,
                        SAXNotSupportedException

Set the value of a property.

The property name is any fully-qualified URI. It is possible for an XMLReader to recognize a property name but to be unable to set its value.

XMLReaders are not required to recognize setting any specific property names, though a core set is provided with SAX2.

Some property values may be immutable or mutable only in specific contexts, such as before, during, or after a parse.

This method is also the standard mechanism for setting extended handlers.

Specified by:

setProperty in interface XMLReader

Parameters:

name - The property name, which is a fully-qualified URI.

value - The requested value for the property.

Throws:

SAXNotRecognizedException - When the XMLReader does not recognize the property name.

SAXNotSupportedException - When the XMLReader recognizes the property name but cannot set the requested value.

setContentHandler

public void setContentHandler(ContentHandler handler)

Register a content handler to receive the output of the transformation filter. If the content handler is also a LexicalHandler, and if no LexicalHandler is separately registered, the ContentHandler will also act as the LexicalHandler

Specified by:

setContentHandler in interface XMLReader

getContentHandler

public ContentHandler getContentHandler()

Get the ContentHandler registered using setContentHandler()

Specified by:

getContentHandler in interface XMLReader

setEntityResolver

public void setEntityResolver(EntityResolver resolver)

Allow an application to register an entity resolver.

If the application does not register an entity resolver, the XMLReader will perform its own default resolution.

Applications may register a new or different resolver in the middle of a parse, and the SAX parser must begin using the new resolver immediately.

Specified by:

setEntityResolver in interface XMLReader

Parameters:

resolver - The entity resolver.

Throws:

NullPointerException - If the resolver argument is null.

See Also:

getEntityResolver()

getEntityResolver

public EntityResolver getEntityResolver()

Return the current entity resolver.

Specified by:

getEntityResolver in interface XMLReader

Returns:

Always null, since no entity resolver is used even if one is supplied.

See Also:

setEntityResolver(org.xml.sax.EntityResolver)

setDTDHandler

public void setDTDHandler(DTDHandler handler)

Allow an application to register a DTD event handler.

If the application does not register a DTD handler, all DTD events reported by the SAX parser will be silently ignored.

Applications may register a new or different handler in the middle of a parse, and the SAX parser must begin using the new handler immediately.

Specified by:

setDTDHandler in interface XMLReader

Parameters:

handler - The DTD handler.

Throws:

NullPointerException - If the handler argument is null.

See Also:

getDTDHandler()

getDTDHandler

public DTDHandler getDTDHandler()

Return the current DTD handler.

Specified by:

getDTDHandler in interface XMLReader

Returns:

Always null, since no DTD handler is used even if one has been supplied.

See Also:

setDTDHandler(org.xml.sax.DTDHandler)

setErrorHandler

public void setErrorHandler(ErrorHandler handler)

Allow an application to register an error event handler.

If the application does not register an error handler, all error events reported by the SAX parser will be silently ignored; however, normal processing may not continue. It is highly recommended that all SAX applications implement an error handler to avoid unexpected bugs.

Applications may register a new or different handler in the middle of a parse, and the SAX parser must begin using the new handler immediately.

Specified by:

setErrorHandler in interface XMLReader

Parameters:

handler - The error handler.

Throws:

NullPointerException - If the handler argument is null.

See Also:

getErrorHandler()

getErrorHandler

public ErrorHandler getErrorHandler()

Return the current error handler.

Specified by:

getErrorHandler in interface XMLReader

Returns:

The current error handler, or null if none has been registered.

See Also:

setErrorHandler(org.xml.sax.ErrorHandler)

parse

public void parse(InputSource input)
           throws IOException,
                  SAXException

Parse an XML document - In the context of a Transformer, this means perform a transformation. The method is equivalent to transform().

Specified by:

parse in interface XMLReader

Parameters:

input - The input source (the XML document to be transformed)

Throws:

SAXException - Any SAX exception, possibly wrapping another exception.

IOException - An IO exception from the parser, possibly from a byte stream or character stream supplied by the application.

See Also:

InputSource, parse(java.lang.String), setEntityResolver(org.xml.sax.EntityResolver), setDTDHandler(org.xml.sax.DTDHandler), setContentHandler(org.xml.sax.ContentHandler), setErrorHandler(org.xml.sax.ErrorHandler)

parse

public void parse(String systemId)
           throws IOException,
                  SAXException

Parse (that is, transform) an XML document given a system identifier (URI).

This method is a shortcut for the common case of reading a document from a system identifier. It is the exact equivalent of the following:

 parse(new InputSource(systemId));
 

If the system identifier is a URL, it must be fully resolved by the application before it is passed to the parser.

Specified by:

parse in interface XMLReader

Parameters:

systemId - The system identifier (URI).

Throws:

SAXException - Any SAX exception, possibly wrapping another exception.

IOException - An IO exception from the parser, possibly from a byte stream or character stream supplied by the application.

See Also:

parse(org.xml.sax.InputSource)

getTransformer

public Transformer getTransformer()

Get the underlying Transformer. This is a Saxon-specific method that allows the user to set parameters on the transformation, set a URIResolver or ErrorListener, etc. New in Saxon 7.2