org.jabber.jabberbeans.sax
Class PacketSubHandler

java.lang.Object
  |
  +--org.jabber.jabberbeans.sax.SubHandler
        |
        +--org.jabber.jabberbeans.sax.PacketSubHandler

Direct Known Subclasses:

InfoQueryHandler, MessageHandler, PresenceHandler

public abstract class PacketSubHandler

extends SubHandler

PacketSubHandler, which provides a framework to subclass for handling base packet types.

Version:

$Revision: 1.1.1.1 $

Author:

David Waite <dwaite@jabber.com>, $Author: lucky $

Field Summary

protected PacketBuilder	builder Builder class for packet types
protected java.lang.StringBuffer	elementChars Buffer for holding characters between elements.

Fields inherited from class org.jabber.jabberbeans.sax.SubHandler

handlerFactory, parent, parser, subCount

Constructor Summary

PacketSubHandler()
Construct a new PacketSubHandler class.Derived in subclasses.

Method Summary

void	characters(char[] ch, int start, int length) Report data characters seen by parser.
protected void	handleEndElement(java.lang.String name) This is an exact copy of the end element in the main handler
protected void	handleStartElement(java.lang.String name, AttributeList attributes) This is an exact copy of the start element in the main handler.
protected void	packetEndElement(java.lang.String name) handleEndElement is a wrapper to let a class derived from this class handle custom element types.
protected boolean	packetStartElement(java.lang.String name, AttributeList attributes) packetStartElement is a method for handling additional element types not defined in the base packet type.
protected void	packetStartHandler(java.lang.String name, AttributeList attributes) packetStartHandler is overloaded by subclasses to initialize additional attributes.
protected void	receiveChildData(SubHandler subhandler, java.lang.Object data) called when a child object returns data (via its stopHandler() method)
protected void	startHandler(java.lang.String name, AttributeList attributes) startHandler is called on the first element handled by the class.
protected java.lang.Object	stopHandler(java.lang.String name) called as the handler is losing scope, to return any data it has created based on the XML it has been fed.

Methods inherited from class org.jabber.jabberbeans.sax.SubHandler

endDocument, endElement, getHandlerFactory, getSubCount, graftParent, graftSubHandler, ignorableWhitespace, processingInstruction, setChildSubHandler, setDocumentLocator, setHandlerFactory, setParent, setParser, startDocument, startElement

Methods inherited from class java.lang.Object

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

Field Detail

builder

protected PacketBuilder builder

Builder class for packet types

elementChars

protected java.lang.StringBuffer elementChars

Buffer for holding characters between elements. The only reason a stringbuffer is used is that most parsers will divide character() events by entities. i.e. "I can't make it tonite 'ok?'" would result in: "I can" , "'" , "t make it tonight " , "'" , "ok?" , "'"

Constructor Detail

PacketSubHandler

public PacketSubHandler()

Construct a new PacketSubHandler class.Derived in subclasses.

Method Detail

handleStartElement

protected final void handleStartElement(java.lang.String name,
                                        AttributeList attributes)
                                 throws SAXException

This is an exact copy of the start element in the main handler.

Overrides:

handleStartElement in class SubHandler

Parameters:

name - string that holds the element name

attributes - AttributeList of attributes going with this element

Throws:

SAXException - thrown on error (unexpected element)

packetStartElement

protected boolean packetStartElement(java.lang.String name,
                                     AttributeList attributes)
                              throws SAXException

packetStartElement is a method for handling additional element types not defined in the base packet type. It is addElement after being filtered.

Returns:

a boolean value of false if the tag should be referred to the extension factory. Basically a 'handled' bit.

Throws:

SAXException - if an error occurs

startHandler

protected final void startHandler(java.lang.String name,
                                  AttributeList attributes)
                           throws SAXException

startHandler is called on the first element handled by the class. This implementation sets up the builder, clears the element character cache, and parsers attributes to pull in the base attribute data.

Overrides:

startHandler in class SubHandler

Parameters:

name - element name

attributes - list of attributes

packetStartHandler

protected void packetStartHandler(java.lang.String name,
                                  AttributeList attributes)

packetStartHandler is overloaded by subclasses to initialize additional attributes.

Parameters:

name - a String value

attributes - an AttributeList value

characters

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

Report data characters seen by parser. This implementation appends the data to the end of a StringBuffer

Overrides:

characters in class SubHandler

Parameters:

ch - character array

start - offset into character array

length - lenght of characters to pull from array

handleEndElement

protected final void handleEndElement(java.lang.String name)
                               throws SAXException

This is an exact copy of the end element in the main handler

Overrides:

handleEndElement in class SubHandler

Parameters:

name - string holding the element name

Throws:

SAXException - thrown on error

packetEndElement

protected void packetEndElement(java.lang.String name)
                         throws SAXException

handleEndElement is a wrapper to let a class derived from this class handle custom element types.

Parameters:

name - a String value holding the element name

Throws:

SAXException - if an error occurs

stopHandler

protected final java.lang.Object stopHandler(java.lang.String name)
                                      throws SAXException

called as the handler is losing scope, to return any data it has created based on the XML it has been fed.

Overrides:

stopHandler in class SubHandler

Parameters:

name - element name

Returns:

Object with whatever relevant data. It is assumed that the parent will know what subclass the child data is in

Throws:

SAXException - in the event of XML parsing errors, or errors detected in the building process for creating the child data.

receiveChildData

protected final void receiveChildData(SubHandler subhandler,
                                      java.lang.Object data)

called when a child object returns data (via its stopHandler() method)

Overrides:

receiveChildData in class SubHandler

Parameters:

subhandler - SubHandler which is returning data

data - Object being returned (parent is assumed to know how to subclass because it created the child)