org.apache.xml.dtm.ref

Class IncrementalSAXSource_Filter

public class IncrementalSAXSource_Filter extends Object implements IncrementalSAXSource, ContentHandler, DTDHandler, LexicalHandler, ErrorHandler, Runnable

IncrementalSAXSource_Filter implements IncrementalSAXSource, using a standard SAX2 event source as its input and parcelling out those events gradually in reponse to deliverMoreNodes() requests. Output from the filter will be passed along to a SAX handler registered as our listener, but those callbacks will pass through a counting stage which periodically yields control back to the controller coroutine.

%REVIEW%: This filter is not currenly intended to be reusable for parsing additional streams/documents. We may want to consider making it resettable at some point in the future. But it's a small object, so that'd be mostly a convenience issue; the cost of allocating each time is trivial compared to the cost of processing any nontrival stream.

For a brief usage example, see the unit-test main() method.

This is a simplification of the old CoroutineSAXParser, focusing specifically on filtering. The resulting controller protocol is _far_ simpler and less error-prone; the only controller operation is deliverMoreNodes(), and the only requirement is that deliverMoreNodes(false) be called if you want to discard the rest of the stream and the previous deliverMoreNodes() didn't return false.

Constructor Summary
IncrementalSAXSource_Filter()
IncrementalSAXSource_Filter(CoroutineManager co, int controllerCoroutineID)
Create a IncrementalSAXSource_Filter which is not yet bound to a specific SAX event source.
Method Summary
voidcharacters(char[] ch, int start, int length)
voidcomment(char[] ch, int start, int length)
static IncrementalSAXSourcecreateIncrementalSAXSource(CoroutineManager co, int controllerCoroutineID)
ObjectdeliverMoreNodes(boolean parsemore)
deliverMoreNodes() is a simple API which tells the coroutine parser that we need more nodes.
voidendCDATA()
voidendDocument()
voidendDTD()
voidendElement(String namespaceURI, String localName, String qName)
voidendEntity(String name)
voidendPrefixMapping(String prefix)
voiderror(SAXParseException exception)
voidfatalError(SAXParseException exception)
intgetControllerCoroutineID()
CoroutineManagergetCoroutineManager()
intgetSourceCoroutineID()
voidignorableWhitespace(char[] ch, int start, int length)
voidinit(CoroutineManager co, int controllerCoroutineID, int sourceCoroutineID)
voidnotationDecl(String a, String b, String c)
voidprocessingInstruction(String target, String data)
voidrun()
voidsetContentHandler(ContentHandler handler)
voidsetDocumentLocator(Locator locator)
voidsetDTDHandler(DTDHandler handler)
voidsetErrHandler(ErrorHandler handler)
voidsetLexicalHandler(LexicalHandler handler)
voidsetReturnFrequency(int events)
voidsetXMLReader(XMLReader eventsource)
Bind our input streams to an XMLReader.
voidskippedEntity(String name)
voidstartCDATA()
voidstartDocument()
voidstartDTD(String name, String publicId, String systemId)
voidstartElement(String namespaceURI, String localName, String qName, Attributes atts)
voidstartEntity(String name)
voidstartParse(InputSource source)
Launch a thread that will run an XMLReader's parse() operation within a thread, feeding events to this IncrementalSAXSource_Filter.
voidstartPrefixMapping(String prefix, String uri)
voidunparsedEntityDecl(String a, String b, String c, String d)
voidwarning(SAXParseException exception)

Constructor Detail

IncrementalSAXSource_Filter

public IncrementalSAXSource_Filter()

IncrementalSAXSource_Filter

public IncrementalSAXSource_Filter(CoroutineManager co, int controllerCoroutineID)
Create a IncrementalSAXSource_Filter which is not yet bound to a specific SAX event source.

Method Detail

characters

public void characters(char[] ch, int start, int length)

comment

public void comment(char[] ch, int start, int length)

createIncrementalSAXSource

public static IncrementalSAXSource createIncrementalSAXSource(CoroutineManager co, int controllerCoroutineID)

deliverMoreNodes

public Object deliverMoreNodes(boolean parsemore)
deliverMoreNodes() is a simple API which tells the coroutine parser that we need more nodes. This is intended to be called from one of our partner routines, and serves to encapsulate the details of how incremental parsing has been achieved.

Parameters: parsemore If true, tells the incremental filter to generate another chunk of output. If false, tells the filter that we're satisfied and it can terminate parsing of this document.

Returns: Boolean.TRUE if there may be more events available by invoking deliverMoreNodes() again. Boolean.FALSE if parsing has run to completion (or been terminated by deliverMoreNodes(false). Or an exception object if something malfunctioned. %REVIEW% We _could_ actually throw the exception, but that would require runinng deliverMoreNodes() in a try/catch... and for many applications, exception will be simply be treated as "not TRUE" in any case.

endCDATA

public void endCDATA()

endDocument

public void endDocument()

endDTD

public void endDTD()

endElement

public void endElement(String namespaceURI, String localName, String qName)

endEntity

public void endEntity(String name)

endPrefixMapping

public void endPrefixMapping(String prefix)

error

public void error(SAXParseException exception)

fatalError

public void fatalError(SAXParseException exception)

getControllerCoroutineID

public int getControllerCoroutineID()

getCoroutineManager

public CoroutineManager getCoroutineManager()

Returns: the CoroutineManager this CoroutineFilter object is bound to. If you're using the do...() methods, applications should only need to talk to the CoroutineManager once, to obtain the application's Coroutine ID.

getSourceCoroutineID

public int getSourceCoroutineID()

ignorableWhitespace

public void ignorableWhitespace(char[] ch, int start, int length)

init

public void init(CoroutineManager co, int controllerCoroutineID, int sourceCoroutineID)

notationDecl

public void notationDecl(String a, String b, String c)

processingInstruction

public void processingInstruction(String target, String data)

run

public void run()

setContentHandler

public void setContentHandler(ContentHandler handler)

setDocumentLocator

public void setDocumentLocator(Locator locator)

setDTDHandler

public void setDTDHandler(DTDHandler handler)

setErrHandler

public void setErrHandler(ErrorHandler handler)

setLexicalHandler

public void setLexicalHandler(LexicalHandler handler)

setReturnFrequency

public void setReturnFrequency(int events)

setXMLReader

public void setXMLReader(XMLReader eventsource)
Bind our input streams to an XMLReader. Just a convenience routine; obviously you can explicitly register this as a listener with the same effect.

skippedEntity

public void skippedEntity(String name)

startCDATA

public void startCDATA()

startDocument

public void startDocument()

startDTD

public void startDTD(String name, String publicId, String systemId)

startElement

public void startElement(String namespaceURI, String localName, String qName, Attributes atts)

startEntity

public void startEntity(String name)

startParse

public void startParse(InputSource source)
Launch a thread that will run an XMLReader's parse() operation within a thread, feeding events to this IncrementalSAXSource_Filter. Mostly a convenience routine, but has the advantage that -- since we invoked parse() -- we can halt parsing quickly via a StopException rather than waiting for the SAX stream to end by itself.

Throws: SAXException is parse thread is already in progress or parsing can not be started.

startPrefixMapping

public void startPrefixMapping(String prefix, String uri)

unparsedEntityDecl

public void unparsedEntityDecl(String a, String b, String c, String d)

warning

public void warning(SAXParseException exception)
Copyright B) 2006 Apache XML Project. All Rights Reserved.