org.xmpp.packet
Class PacketExtension

java.lang.Object
  org.xmpp.packet.PacketExtension

Direct Known Subclasses:

DataForm

public class PacketExtension
extends Object

A packet extension represents a child element of a Packet for a given qualified name. The PacketExtension acts as a wrapper on a child element the same way Packet does for a whole element. The wrapper provides an easy way to handle the packet extension.

Subclasses of this class can be registered using the static variable registeredExtensions. The registration process associates the new subclass with a given qualified name (ie. element name and namespace). This information will be used by Packet.getExtension(String, String) for locating the corresponding PacketExtension subclass to return for the requested qualified name. Each PacketExtension must have a public constructor that takes an Element instance as an argument.

Author:

Gaston Dombiak

Field Summary

protected static org.dom4j.DocumentFactory	docFactory
protected org.dom4j.Element	element
protected static Map<org.dom4j.QName,Class>	registeredExtensions Subclasses of PacketExtension should register the element name and namespace that the subclass is using.

Constructor Summary

PacketExtension(org.dom4j.Element element)
Constructs a new PacketExtension.

PacketExtension(String name, String namespace)
Constructs a new Packet extension using the specified name and namespace.

Method Summary

PacketExtension	createCopy() Creates a deep copy of this packet extension.
org.dom4j.Element	getElement() Returns the DOM4J Element that backs the packet.
static Class	getExtensionClass(String name, String namespace) Returns the extension class to use for the specified element name and namespace.

Methods inherited from class java.lang.Object

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

Field Detail

docFactory

protected static org.dom4j.DocumentFactory docFactory

registeredExtensions

protected static Map<org.dom4j.QName,Class> registeredExtensions

Subclasses of PacketExtension should register the element name and namespace that the subclass is using.

element

protected org.dom4j.Element element

Constructor Detail

PacketExtension

public PacketExtension(String name,
                       String namespace)

Constructs a new Packet extension using the specified name and namespace.

Parameters:

name - the child element name.

namespace - the child element namespace.

PacketExtension

public PacketExtension(org.dom4j.Element element)

Constructs a new PacketExtension.

Parameters:

element - the XML Element that contains the packet extension contents.

Method Detail

getExtensionClass

public static Class getExtensionClass(String name,
                                      String namespace)

Returns the extension class to use for the specified element name and namespace. For instance, the DataForm class should be used for the element "x" and namespace "jabber:x:data".

Parameters:

name - the child element name.

namespace - the child element namespace.

Returns:

the extension class to use for the specified element name and namespace.

getElement

public org.dom4j.Element getElement()

Returns the DOM4J Element that backs the packet. The element is the definitive representation of the packet and can be manipulated directly to change packet contents.

Returns:

the DOM4J Element that represents the packet.

createCopy

public PacketExtension createCopy()

Creates a deep copy of this packet extension.

Returns:

a deep copy of this packet extension.