org.dom4j.io

Class DispatchHandler

java.lang.Object

org.dom4j.io.DispatchHandler

All Implemented Interfaces:

ElementHandler

Direct Known Subclasses:

PruningDispatchHandler

class DispatchHandler
extends java.lang.Object
implements ElementHandler

DispatchHandler implements the ElementHandler interface and provides a means to register multiple ElementHandler instances to be used by an event based processor. This is a special ElementHandler in that it's onStart and onEnd implementation methods are called for every element encountered during the parse. It then delegates to other ElementHandler instances registered with it to process the elements encountered.

Version:

$Revision: 1.11 $

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	atRoot Whether the parser is at the root element or not
private ElementHandler	defaultHandler ElementHandler to use by default for element paths with no handlers registered
private java.util.HashMap<java.lang.String,ElementHandler>	handlers HashMap maintains the mapping between element paths and handlers
private java.util.ArrayList<ElementHandler>	handlerStack maintains a stack of previously encountered handlers
private java.lang.String	path The current path in the XML tree (i.e.
private java.util.ArrayList<java.lang.String>	pathStack maintains a stack of previously encountered paths

Constructor Summary

Constructors

Constructor and Description
DispatchHandler()

Method Summary

Modifier and Type	Method and Description
void	addHandler(java.lang.String handlerPath, ElementHandler handler) Adds the ElementHandler to be called when the specified path is encounted.
boolean	containsHandler(java.lang.String handlerPath) DOCUMENT ME!
int	getActiveHandlerCount() Returns the number of ElementHandlerobjects that are waiting for their elements closing tag.
ElementHandler	getHandler(java.lang.String handlerPath) Get the registered ElementHandlerfor the specified path.
java.lang.String	getPath() DOCUMENT ME!
void	onEnd(ElementPath elementPath) Called by an event based processor when an elements closing tag is encountered.
void	onStart(ElementPath elementPath) Called by an event based processor when an elements openning tag is encountered.
ElementHandler	removeHandler(java.lang.String handlerPath) Removes the ElementHandler from the event based processor, for the specified path.
void	resetHandlers() Used to remove all the Element Handlers and return things back to the way they were when object was created.
void	setDefaultHandler(ElementHandler handler) When multiple ElementHandler instances have been registered, this will set a default ElementHandler to be called for any path which does NOT have a handler registered.

Methods inherited from class java.lang.Object

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

Field Detail

atRoot

private boolean atRoot

Whether the parser is at the root element or not

path

private java.lang.String path

The current path in the XML tree (i.e. /a/b/c)

pathStack

private java.util.ArrayList<java.lang.String> pathStack

maintains a stack of previously encountered paths

handlerStack

private java.util.ArrayList<ElementHandler> handlerStack

maintains a stack of previously encountered handlers

handlers

private java.util.HashMap<java.lang.String,ElementHandler> handlers

HashMap maintains the mapping between element paths and handlers

defaultHandler

private ElementHandler defaultHandler

ElementHandler to use by default for element paths with no handlers registered

Constructor Detail

DispatchHandler

public DispatchHandler()

Method Detail

addHandler

public void addHandler(java.lang.String handlerPath,
                       ElementHandler handler)

Adds the ElementHandler to be called when the specified path is encounted.

Parameters:

handlerPath - is the path to be handled

handler - is the ElementHandler to be called by the event based processor.

removeHandler

public ElementHandler removeHandler(java.lang.String handlerPath)

Removes the ElementHandler from the event based processor, for the specified path.

Parameters:

handlerPath - is the path to remove the ElementHandler for.

Returns:

DOCUMENT ME!

containsHandler

public boolean containsHandler(java.lang.String handlerPath)

DOCUMENT ME!

Parameters:

handlerPath - DOCUMENT ME!

Returns:

true when an ElementHandler is registered for the specified path.

getHandler

public ElementHandler getHandler(java.lang.String handlerPath)

Get the registered ElementHandlerfor the specified path.

Parameters:

handlerPath - XML path to get the handler for

Returns:

the registered handler

getActiveHandlerCount

public int getActiveHandlerCount()

Returns the number of ElementHandlerobjects that are waiting for their elements closing tag.

Returns:

number of active handlers

setDefaultHandler

public void setDefaultHandler(ElementHandler handler)

When multiple ElementHandler instances have been registered, this will set a default ElementHandler to be called for any path which does NOT have a handler registered.

Parameters:

handler - is the ElementHandler to be called by the event based processor.

resetHandlers

public void resetHandlers()

Used to remove all the Element Handlers and return things back to the way they were when object was created.

getPath

public java.lang.String getPath()

DOCUMENT ME!

Returns:

the current path for the parse

onStart

public void onStart(ElementPath elementPath)

Description copied from interface: ElementHandler

Called by an event based processor when an elements openning tag is encountered.

Specified by:

onStart in interface ElementHandler

Parameters:

elementPath - is the current ElementPath to process

onEnd

public void onEnd(ElementPath elementPath)

Description copied from interface: ElementHandler

Called by an event based processor when an elements closing tag is encountered.

Specified by:

onEnd in interface ElementHandler

Parameters:

elementPath - is the current ElementPath to process