org.xmpp.packet.Packet Maven / Gradle / Ivy
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/**
* Copyright (C) 2004-2008 Jive Software. All rights reserved.
*
* This software is published under the terms of the GNU Public License (GPL),
* a copy of which is included in this distribution, or a commercial license
* agreement with Jive.
*/
package org.xmpp.packet;
import org.dom4j.DocumentFactory;
import org.dom4j.Element;
import org.dom4j.QName;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;
import java.io.StringWriter;
import java.lang.reflect.Constructor;
import java.util.List;
/**
* An XMPP packet (also referred to as a stanza). Each packet is backed by a
* DOM4J Element. A set of convenience methods allows easy manipulation of
* the Element, or the Element can be accessed directly and manipulated.
*
* There are three core packet types:
* - {@link Message} -- used to send data between users.
*
- {@link Presence} -- contains user presence information or is used
* to manage presence subscriptions.
*
- {@link IQ} -- exchange information and perform queries using a
* request/response protocol.
*
*
* @author Matt Tucker
*/
public abstract class Packet {
protected static DocumentFactory docFactory = DocumentFactory.getInstance();
protected Element element;
// Cache to and from JIDs
protected JID toJID;
protected JID fromJID;
/**
* Constructs a new Packet. The TO address contained in the XML Element will only be
* validated. In other words, stringprep operations will only be performed on the TO JID to
* verify that it is well-formed. The FROM address is assigned by the server so there is no
* need to verify it.
*
* @param element the XML Element that contains the packet contents.
*/
public Packet(Element element) {
this(element, false);
}
/**
* Constructs a new Packet. The JID address contained in the XML Element may not be
* validated. When validation can be skipped then stringprep operations will not be performed
* on the JIDs to verify that addresses are well-formed. However, when validation cannot be
* skipped then only the TO address will be verified. The FROM address is assigned by
* the server so there is no need to verify it.
*
* @param element the XML Element that contains the packet contents.
* @param skipValidation true if stringprep should not be applied to the TO address.
*/
public Packet(Element element, boolean skipValidation) {
this.element = element;
// Apply stringprep profiles to the "to" and "from" values.
String to = element.attributeValue("to");
if (to != null) {
if (to.length() == 0) {
// Remove empty TO values
element.addAttribute("to", null);
}
else {
String[] parts = JID.getParts(to);
toJID = new JID(parts[0], parts[1], parts[2], skipValidation);
element.addAttribute("to", toJID.toString());
}
}
String from = element.attributeValue("from");
if (from != null) {
if (from.length() == 0) {
// Remove empty FROM values
element.addAttribute("from", null);
}
else {
String[] parts = JID.getParts(from);
fromJID = new JID(parts[0], parts[1], parts[2], true);
element.addAttribute("from", fromJID.toString());
}
}
}
/**
* Constructs a new Packet with no element data. This method is used by
* extensions of this class that require a more optimized path for creating
* new packets.
*/
protected Packet() {
}
/**
* Returns the packet ID, or null if the packet does not have an ID.
* Packet ID's are optional, except for IQ packets.
*
* @return the packet ID.
*/
public String getID() {
return element.attributeValue("id");
}
/**
* Sets the packet ID. Packet ID's are optional, except for IQ packets.
*
* @param ID the packet ID.
*/
public void setID(String ID) {
element.addAttribute("id", ID);
}
/**
* Returns the XMPP address (JID) that the packet is addressed to, or null
* if the "to" attribute is not set. The XMPP protocol often makes the "to"
* attribute optional, so it does not always need to be set.
*
* @return the XMPP address (JID) that the packet is addressed to, or null
* if not set.
*/
public JID getTo() {
String to = element.attributeValue("to");
if (to == null || to.length() == 0) {
return null;
}
else {
if (toJID != null && to.equals(toJID.toString())) {
return toJID;
}
else {
// Return a new JID that bypasses stringprep profile checking.
// This improves speed and is safe as long as the user doesn't
// directly manipulate the attributes of the underlying Element
// that represent JID's.
String[] parts = JID.getParts(to);
toJID = new JID(parts[0], parts[1], parts[2], true);
return toJID;
}
}
}
/**
* Sets the XMPP address (JID) that the packet is addressed to. The XMPP protocol
* often makes the "to" attribute optional, so it does not always need to be set.
*
* @param to the XMPP address (JID) that the packet is addressed to.
*/
public void setTo(String to) {
// Apply stringprep profiles to value.
if (to != null) {
toJID = new JID(to);
to = toJID.toString();
}
element.addAttribute("to", to);
}
/**
* Sets the XMPP address (JID) that the packet is address to. The XMPP protocol
* often makes the "to" attribute optional, so it does not always need to be set.
*
* @param to the XMPP address (JID) that the packet is addressed to.
*/
public void setTo(JID to) {
toJID = to;
if (to == null) {
element.addAttribute("to", null);
}
else {
element.addAttribute("to", to.toString());
}
}
/**
* Returns the XMPP address (JID) that the packet is from, or null
* if the "from" attribute is not set. The XMPP protocol often makes the "from"
* attribute optional, so it does not always need to be set.
*
* @return the XMPP address that the packet is from, or null
* if not set.
*/
public JID getFrom() {
String from = element.attributeValue("from");
if (from == null || from.length() == 0) {
return null;
}
else {
if (fromJID != null && from.equals(fromJID.toString())) {
return fromJID;
}
else {
// Return a new JID that bypasses stringprep profile checking.
// This improves speed and is safe as long as the user doesn't
// directly manipulate the attributes of the underlying Element
// that represent JID's.
String[] parts = JID.getParts(from);
fromJID = new JID(parts[0], parts[1], parts[2], true);
return fromJID;
}
}
}
/**
* Sets the XMPP address (JID) that the packet comes from. The XMPP protocol
* often makes the "from" attribute optional, so it does not always need to be set.
*
* @param from the XMPP address (JID) that the packet comes from.
*/
public void setFrom(String from) {
// Apply stringprep profiles to value.
if (from != null) {
fromJID = new JID(from);
from = fromJID.toString();
}
element.addAttribute("from", from);
}
/**
* Sets the XMPP address (JID) that the packet comes from. The XMPP protocol
* often makes the "from" attribute optional, so it does not always need to be set.
*
* @param from the XMPP address (JID) that the packet comes from.
*/
public void setFrom(JID from) {
fromJID = from;
if (from == null) {
element.addAttribute("from", null);
}
else {
element.addAttribute("from", from.toString());
}
}
/**
* Adds the element contained in the PacketExtension to the element of this packet.
* It is important that this is the first and last time the element contained in
* PacketExtension is added to another Packet. Otherwise, a runtime error will be
* thrown when trying to add the PacketExtension's element to the Packet's element.
* Future modifications to the PacketExtension will be reflected in this Packet.
*
* @param extension the PacketExtension whose element will be added to this Packet's element.
*/
public void addExtension(PacketExtension extension) {
element.add(extension.getElement());
}
/**
* Returns a {@link PacketExtension} on the first element found in this packet
* for the specified name and namespace or null if
* none was found.
*
* @param name the child element name.
* @param namespace the child element namespace.
* @return a PacketExtension on the first element found in this packet for the specified
* name and namespace or null if none was found.
*/
@SuppressWarnings("unchecked")
public PacketExtension getExtension(String name, String namespace) {
List extensions = element.elements(QName.get(name, namespace));
if (!extensions.isEmpty()) {
Class extensionClass = PacketExtension.getExtensionClass(name, namespace);
// If a specific PacketExtension implementation has been registered, use that.
if (extensionClass != null) {
try {
Constructor constructor = extensionClass.getDeclaredConstructor(Element.class);
return constructor.newInstance(extensions.get(0));
}
catch (Exception e) {
// Ignore.
}
}
// Otherwise, use a normal PacketExtension.
else {
return new PacketExtension(extensions.get(0));
}
}
return null;
}
/**
* Deletes the first element whose element name and namespace matches the specified
* element name and namespace.
*
* Notice that this method may remove any child element that matches the specified
* element name and namespace even if that element was not added to the Packet using a
* {@link PacketExtension}.
*
*
* @param name the child element name.
* @param namespace the child element namespace.
* @return true if a child element was removed.
*/
@SuppressWarnings("unchecked")
public boolean deleteExtension(String name, String namespace) {
List extensions = element.elements(QName.get(name, namespace));
if (!extensions.isEmpty()) {
element.remove(extensions.get(0));
return true;
}
return false;
}
/**
* Returns the packet error, or null if there is no packet error.
*
* @return the packet error.
*/
public PacketError getError() {
Element error = element.element("error");
if (error != null) {
return new PacketError(error);
}
return null;
}
/**
* Sets the packet error. Calling this method will automatically set
* the packet "type" attribute to "error".
*
* @param error the packet error.
*/
public void setError(PacketError error) {
if (element == null) {
throw new NullPointerException("Error cannot be null");
}
// Force the packet type to "error".
element.addAttribute("type", "error");
// Remove an existing error packet.
if (element.element("error") != null) {
element.remove(element.element("error"));
}
// Add the error element.
element.add(error.getElement());
}
/**
* Sets the packet error using the specified condition. Calling this
* method will automatically set the packet "type" attribute to "error".
* This is a convenience method equivalent to calling:
*
* setError(new PacketError(condition));
*
* @param condition the error condition.
*/
public void setError(PacketError.Condition condition) {
setError(new PacketError(condition));
}
/**
* Creates a deep copy of this packet.
*
* @return a deep copy of this packet.
*/
public abstract Packet createCopy();
/**
* 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.
*
* @return the DOM4J Element that represents the packet.
*/
public Element getElement() {
return element;
}
/**
* Returns the textual XML representation of this packet.
*
* @return the textual XML representation of this packet.
*/
public String toXML() {
return element.asXML();
}
public String toString() {
StringWriter out = new StringWriter();
XMLWriter writer = new XMLWriter(out, OutputFormat.createPrettyPrint());
try {
writer.write(element);
}
catch (Exception e) {
// Ignore.
}
return out.toString();
}
}