/**
* $RCSfile$
* $Revision$
* $Date$
*
* Copyright 2003-2007 Jive Software.
*
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smack.packet;
import org.jivesoftware.smack.util.StringUtils;
import java.io.ByteArrayOutputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;
/**
* Base class for XMPP packets. Every packet has a unique ID (which is automatically
* generated, but can be overriden). Optionally, the "to" and "from" fields can be set,
* as well as an arbitrary number of properties.
*
* Properties provide an easy mechanism for clients to share data. Each property has a
* String name, and a value that is a Java primitive (int, long, float, double, boolean)
* or any Serializable object (a Java object is Serializable when it implements the
* Serializable interface).
*
* @author Matt Tucker
*/
public abstract class Packet {
protected static final String DEFAULT_LANGUAGE =
java.util.Locale.getDefault().getLanguage().toLowerCase();
private static String DEFAULT_XML_NS = null;
/**
* Constant used as packetID to indicate that a packet has no id. To indicate that a packet
* has no id set this constant as the packet's id. When the packet is asked for its id the
* answer will be <tt>null</tt>.
*/
public static final String ID_NOT_AVAILABLE = "ID_NOT_AVAILABLE";
/**
* A prefix helps to make sure that ID's are unique across mutliple instances.
*/
private static String prefix = StringUtils.randomString(5) + "-";
/**
* Keeps track of the current increment, which is appended to the prefix to
* forum a unique ID.
*/
private static long id = 0;
private String xmlns = DEFAULT_XML_NS;
/**
* Returns the next unique id. Each id made up of a short alphanumeric
* prefix along with a unique numeric value.
*
* @return the next id.
*/
public static synchronized String nextID() {
return prefix + Long.toString(id++);
}
public static void setDefaultXmlns(String defaultXmlns) {
DEFAULT_XML_NS = defaultXmlns;
}
private String packetID = null;
private String to = null;
private String from = null;
private final List<PacketExtension> packetExtensions
= new CopyOnWriteArrayList<PacketExtension>();
private final Map<String,Object> properties = new HashMap<String, Object>();
private XMPPError error = null;
public Packet() {
}
public Packet(Packet p) {
packetID = p.getPacketID();
to = p.getTo();
from = p.getFrom();
xmlns = p.xmlns;
error = p.error;
// Copy extensions
for (PacketExtension pe : p.getExtensions()) {
addExtension(pe);
}
}
/**
* Returns the unique ID of the packet. The returned value could be <tt>null</tt> when
* ID_NOT_AVAILABLE was set as the packet's id.
*
* @return the packet's unique ID or <tt>null</tt> if the packet's id is not available.
*/
public String getPacketID() {
if (ID_NOT_AVAILABLE.equals(packetID)) {
return null;
}
if (packetID == null) {
packetID = nextID();
}
return packetID;
}
/**
* Sets the unique ID of the packet. To indicate that a packet has no id
* pass the constant ID_NOT_AVAILABLE as the packet's id value.
*
* @param packetID the unique ID for the packet.
*/
public void setPacketID(String packetID) {
this.packetID = packetID;
}
/**
* Returns who the packet is being sent "to", or <tt>null</tt> if
* the value is not set. The XMPP protocol often makes the "to"
* attribute optional, so it does not always need to be set.<p>
*
* The StringUtils class provides several useful methods for dealing with
* XMPP addresses such as parsing the
* {@link StringUtils#parseBareAddress(String) bare address},
* {@link StringUtils#parseName(String) user name},
* {@link StringUtils#parseServer(String) server}, and
* {@link StringUtils#parseResource(String) resource}.
*
* @return who the packet is being sent to, or <tt>null</tt> if the
* value has not been set.
*/
public String getTo() {
return to;
}
/**
* Sets who the packet is being sent "to". The XMPP protocol often makes
* the "to" attribute optional, so it does not always need to be set.
*
* @param to who the packet is being sent to.
*/
public void setTo(String to) {
this.to = to;
}
/**
* Returns who the packet is being sent "from" or <tt>null</tt> if
* the value is not set. The XMPP protocol often makes the "from"
* attribute optional, so it does not always need to be set.<p>
*
* The StringUtils class provides several useful methods for dealing with
* XMPP addresses such as parsing the
* {@link StringUtils#parseBareAddress(String) bare address},
* {@link StringUtils#parseName(String) user name},
* {@link StringUtils#parseServer(String) server}, and
* {@link StringUtils#parseResource(String) resource}.
*
* @return who the packet is being sent from, or <tt>null</tt> if the
* value has not been set.
*/
public String getFrom() {
return from;
}
/**
* Sets who the packet is being sent "from". The XMPP protocol often
* makes the "from" attribute optional, so it does not always need to
* be set.
*
* @param from who the packet is being sent to.
*/
public void setFrom(String from) {
this.from = from;
}
/**
* Returns the error associated with this packet, or <tt>null</tt> if there are
* no errors.
*
* @return the error sub-packet or <tt>null</tt> if there isn't an error.
*/
public XMPPError getError() {
return error;
}
/**
* Sets the error for this packet.
*
* @param error the error to associate with this packet.
*/
public void setError(XMPPError error) {
this.error = error;
}
/**
* Returns an unmodifiable collection of the packet extensions attached to the packet.
*
* @return the packet extensions.
*/
public synchronized Collection<PacketExtension> getExtensions() {
if (packetExtensions == null) {
return Collections.emptyList();
}
return Collections.unmodifiableList(new ArrayList<PacketExtension>(packetExtensions));
}
/**
* Returns the first extension of this packet that has the given namespace.
*
* @param namespace the namespace of the extension that is desired.
* @return the packet extension with the given namespace.
*/
public PacketExtension getExtension(String namespace) {
return getExtension(null, namespace);
}
/**
* Returns the first packet extension that matches the specified element name and
* namespace, or <tt>null</tt> if it doesn't exist. If the provided elementName is null
* than only the provided namespace is attempted to be matched. Packet extensions are
* are arbitrary XML sub-documents in standard XMPP packets. By default, a
* DefaultPacketExtension instance will be returned for each extension. However,
* PacketExtensionProvider instances can be registered with the
* {@link org.jivesoftware.smack.provider.ProviderManager ProviderManager}
* class to handle custom parsing. In that case, the type of the Object
* will be determined by the provider.
*
* @param elementName the XML element name of the packet extension. (May be null)
* @param namespace the XML element namespace of the packet extension.
* @return the extension, or <tt>null</tt> if it doesn't exist.
*/
public PacketExtension getExtension(String elementName, String namespace) {
if (namespace == null) {
return null;
}
for (PacketExtension ext : packetExtensions) {
if ((elementName == null || elementName.equals(ext.getElementName()))
&& namespace.equals(ext.getNamespace()))
{
return ext;
}
}
return null;
}
/**
* Adds a packet extension to the packet. Does nothing if extension is null.
*
* @param extension a packet extension.
*/
public void addExtension(PacketExtension extension) {
if (extension == null) return;
packetExtensions.add(extension);
}
/**
* Adds a collection of packet extensions to the packet. Does nothing if extensions is null.
*
* @param extensions a collection of packet extensions
*/
public void addExtensions(Collection<PacketExtension> extensions) {
if (extensions == null) return;
packetExtensions.addAll(extensions);
}
/**
* Removes a packet extension from the packet.
*
* @param extension the packet extension to remove.
*/
public void removeExtension(PacketExtension extension) {
packetExtensions.remove(extension);
}
/**
* Returns the packet property with the specified name or <tt>null</tt> if the
* property doesn't exist. Property values that were originally primitives will
* be returned as their object equivalent. For example, an int property will be
* returned as an Integer, a double as a Double, etc.
*
* @param name the name of the property.
* @return the property, or <tt>null</tt> if the property doesn't exist.
*/
public synchronized Object getProperty(String name) {
if (properties == null) {
return null;
}
return properties.get(name);
}
/**
* Sets a property with an Object as the value. The value must be Serializable
* or an IllegalArgumentException will be thrown.
*
* @param name the name of the property.
* @param value the value of the property.
*/
public synchronized void setProperty(String name, Object value) {
if (!(value instanceof Serializable)) {
throw new IllegalArgumentException("Value must be serialiazble");
}
properties.put(name, value);
}
/**
* Deletes a property.
*
* @param name the name of the property to delete.
*/
public synchronized void deleteProperty(String name) {
if (properties == null) {
return;
}
properties.remove(name);
}
/**
* Returns an unmodifiable collection of all the property names that are set.
*
* @return all property names.
*/
public synchronized Collection<String> getPropertyNames() {
if (properties == null) {
return Collections.emptySet();
}
return Collections.unmodifiableSet(new HashSet<String>(properties.keySet()));
}
/**
* Returns the packet as XML. Every concrete extension of Packet must implement
* this method. In addition to writing out packet-specific data, every sub-class
* should also write out the error and the extensions data if they are defined.
*
* @return the XML format of the packet as a String.
*/
public abstract String toXML();
/**
* Returns the extension sub-packets (including properties data) as an XML
* String, or the Empty String if there are no packet extensions.
*
* @return the extension sub-packets as XML or the Empty String if there
* are no packet extensions.
*/
protected synchronized String getExtensionsXML() {
StringBuilder buf = new StringBuilder();
// Add in all standard extension sub-packets.
for (PacketExtension extension : getExtensions()) {
buf.append(extension.toXML());
}
// Add in packet properties.
if (properties != null && !properties.isEmpty()) {
buf.append("<properties xmlns=\"http://www.jivesoftware.com/xmlns/xmpp/properties\">");
// Loop through all properties and write them out.
for (String name : getPropertyNames()) {
Object value = getProperty(name);
buf.append("<property>");
buf.append("<name>").append(StringUtils.escapeForXML(name)).append("</name>");
buf.append("<value type=\"");
if (value instanceof Integer) {
buf.append("integer\">").append(value).append("</value>");
}
else if (value instanceof Long) {
buf.append("long\">").append(value).append("</value>");
}
else if (value instanceof Float) {
buf.append("float\">").append(value).append("</value>");
}
else if (value instanceof Double) {
buf.append("double\">").append(value).append("</value>");
}
else if (value instanceof Boolean) {
buf.append("boolean\">").append(value).append("</value>");
}
else if (value instanceof String) {
buf.append("string\">");
buf.append(StringUtils.escapeForXML((String)value));
buf.append("</value>");
}
// Otherwise, it's a generic Serializable object. Serialized objects are in
// a binary format, which won't work well inside of XML. Therefore, we base-64
// encode the binary data before adding it.
else {
ByteArrayOutputStream byteStream = null;
ObjectOutputStream out = null;
try {
byteStream = new ByteArrayOutputStream();
out = new ObjectOutputStream(byteStream);
out.writeObject(value);
buf.append("java-object\">");
String encodedVal = StringUtils.encodeBase64(byteStream.toByteArray());
buf.append(encodedVal).append("</value>");
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if (out != null) {
try {
out.close();
}
catch (Exception e) {
// Ignore.
}
}
if (byteStream != null) {
try {
byteStream.close();
}
catch (Exception e) {
// Ignore.
}
}
}
}
buf.append("</property>");
}
buf.append("</properties>");
}
return buf.toString();
}
public String getXmlns() {
return this.xmlns;
}
/**
* Returns the default language used for all messages containing localized content.
*
* @return the default language
*/
public static String getDefaultLanguage() {
return DEFAULT_LANGUAGE;
}
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Packet packet = (Packet) o;
if (error != null ? !error.equals(packet.error) : packet.error != null) { return false; }
if (from != null ? !from.equals(packet.from) : packet.from != null) { return false; }
if (!packetExtensions.equals(packet.packetExtensions)) { return false; }
if (packetID != null ? !packetID.equals(packet.packetID) : packet.packetID != null) {
return false;
}
if (properties != null ? !properties.equals(packet.properties)
: packet.properties != null) {
return false;
}
if (to != null ? !to.equals(packet.to) : packet.to != null) { return false; }
return !(xmlns != null ? !xmlns.equals(packet.xmlns) : packet.xmlns != null);
}
public int hashCode() {
int result;
result = (xmlns != null ? xmlns.hashCode() : 0);
result = 31 * result + (packetID != null ? packetID.hashCode() : 0);
result = 31 * result + (to != null ? to.hashCode() : 0);
result = 31 * result + (from != null ? from.hashCode() : 0);
result = 31 * result + packetExtensions.hashCode();
result = 31 * result + properties.hashCode();
result = 31 * result + (error != null ? error.hashCode() : 0);
return result;
}
}