Java tutorial
/** * Copyright (C) 2004-2009 Jive Software. All rights reserved. * Copyright (C) 2014-2015 TU Berlin. 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 de.tu_berlin.cit.intercloud.xmpp.core.packet; import org.dom4j.Element; import org.dom4j.Namespace; import org.dom4j.QName; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.Iterator; /** * Roster packet. The roster is a list of JIDs (typically other users) that * the user wishes to track the presence of. Each roster item is keyed by * JID and contains a nickname (optional), subscription type, and list of * groups (optional). * * @author Matt Tucker */ public class Roster extends IQ { /** * Constructs a new Roster with an automatically generated ID and a type * of {@link IQ.Type#get}. */ public Roster() { super(); element.addElement("query", "jabber:iq:roster"); } /** * Constructs a new Roster using the specified type. A packet ID will * be automatically generated. * * @param type the IQ type. */ public Roster(Type type) { super(type); element.addElement("query", "jabber:iq:roster"); } /** * Constructs a new Roster using the specified type and ID. * * @param type the IQ type. * @param ID the packet ID of the IQ. */ public Roster(Type type, String ID) { super(type, ID); element.addElement("query", "jabber:iq:roster"); } /** * Constructs a new Roster that is a copy of an existing Roster. * * @param roster the roster packet. * @see #createCopy() */ private Roster(Roster roster) { Element elementCopy = roster.element.createCopy(); docFactory.createDocument().add(elementCopy); this.element = elementCopy; } /** * Constructs a new Roster using an existing Element. This is useful * for parsing incoming roster Elements into Roster objects. * * @param element the Roster Element. */ public Roster(Element element) { super(element); } /** * Adds a new item to the roster. The name and groups are set to <tt>null</tt> * If the roster packet already contains an item using the same JID, the * information in the existing item will be overwritten with the new information.<p> * * The XMPP specification recommends that if the roster item is associated with another * instant messaging user (human), that the JID be in bare form (e.g. user@domain). * Use the {@link JID#toBareJID() toBareJID()} method for a bare JID. * * @param jid the JID. * @param subscription the subscription type. * @return the newly created item. */ public Item addItem(String jid, Subscription subscription) { if (getType() == IQ.Type.get || getType() == IQ.Type.error) { throw new IllegalStateException("IQ type must be 'result' or 'set'"); } if (jid == null) { throw new NullPointerException("JID cannot be null"); } return addItem(new JID(jid), null, null, subscription, null); } /** * Adds a new item to the roster. The name and groups are set to <tt>null</tt> * If the roster packet already contains an item using the same JID, the * information in the existing item will be overwritten with the new information.<p> * * The XMPP specification recommends that if the roster item is associated with another * instant messaging user (human), that the JID be in bare form (e.g. user@domain). * Use the {@link JID#toBareJID() toBareJID()} method for a bare JID. * * @param jid the JID. * @param subscription the subscription type. * @return the newly created item. */ public Item addItem(JID jid, Subscription subscription) { if (getType() != IQ.Type.result && getType() != IQ.Type.set) { throw new IllegalStateException("IQ type must be 'result' or 'set'"); } if (jid == null) { throw new NullPointerException("JID cannot be null"); } return addItem(jid, null, null, subscription, null); } /** * Adds a new item to the roster. If the roster packet already contains an item * using the same JID, the information in the existing item will be overwritten * with the new information.<p> * * The XMPP specification recommends that if the roster item is associated with another * instant messaging user (human), that the JID be in bare form (e.g. user@domain). * Use the {@link JID#toBareJID() toBareJID()} method for a bare JID. * * @param jid the JID. * @param name the nickname. * @param ask the ask type. * @param subscription the subscription type. * @param groups a Collection of groups. * @return the newly created item. */ @SuppressWarnings("unchecked") public Item addItem(JID jid, String name, Ask ask, Subscription subscription, Collection<String> groups) { if (jid == null) { throw new NullPointerException("JID cannot be null"); } if (subscription == null) { throw new NullPointerException("Subscription cannot be null"); } Element query = element.element(new QName("query", Namespace.get("jabber:iq:roster"))); if (query == null) { query = element.addElement("query", "jabber:iq:roster"); } Element item = null; for (Iterator<Element> i = query.elementIterator("item"); i.hasNext();) { Element el = i.next(); if (el.attributeValue("jid").equals(jid.toString())) { item = el; } } if (item == null) { item = query.addElement("item"); } item.addAttribute("jid", jid.toBareJID()); item.addAttribute("name", name); if (ask != null) { item.addAttribute("ask", ask.toString()); } item.addAttribute("subscription", subscription.toString()); // Erase existing groups in case the item previously existed. for (Iterator<Element> i = item.elementIterator("group"); i.hasNext();) { item.remove(i.next()); } // Add in groups. if (groups != null) { for (String group : groups) { item.addElement("group").setText(group); } } return new Item(jid, name, ask, subscription, groups); } /** * Removes an item from this roster. * * @param jid the JID of the item to remove. */ @SuppressWarnings("unchecked") public void removeItem(JID jid) { Element query = element.element(new QName("query", Namespace.get("jabber:iq:roster"))); if (query != null) { for (Iterator<Element> i = query.elementIterator("item"); i.hasNext();) { Element item = i.next(); if (item.attributeValue("jid").equals(jid.toString())) { query.remove(item); return; } } } } /** * Returns an unmodifiable copy of the {@link Item Items} in the roster packet. * * @return an unmodifable copy of the {@link Item Items} in the roster packet. */ @SuppressWarnings("unchecked") public Collection<Item> getItems() { Collection<Item> items = new ArrayList<Item>(); Element query = element.element(new QName("query", Namespace.get("jabber:iq:roster"))); if (query != null) { for (Iterator<Element> i = query.elementIterator("item"); i.hasNext();) { Element item = i.next(); String jid = item.attributeValue("jid"); String name = item.attributeValue("name"); String ask = item.attributeValue("ask"); String subscription = item.attributeValue("subscription"); Collection<String> groups = new ArrayList<String>(); for (Iterator<Element> j = item.elementIterator("group"); j.hasNext();) { Element group = j.next(); groups.add(group.getText().trim()); } Ask askStatus = ask == null ? null : Ask.valueOf(ask); Subscription subStatus = subscription == null ? null : Subscription.valueOf(subscription); items.add(new Item(new JID(jid), name, askStatus, subStatus, groups)); } } return Collections.unmodifiableCollection(items); } /** * Returns a deep copy of this Roster. * * @return a deep copy of this Roster. */ public Roster createCopy() { return new Roster(this); } /** * Item in a roster, which represents an individual contact. Each contact * has a JID, an optional nickname, a subscription type, and can belong to * one ore more groups. */ public static class Item { private JID jid; private String name; private Ask ask; private Subscription subscription; private Collection<String> groups; /** * Constructs a new roster item. * * @param jid the JID. * @param name the nickname. * @param ask the ask state. * @param subscription the subscription state. * @param groups the item groups. */ private Item(JID jid, String name, Ask ask, Subscription subscription, Collection<String> groups) { this.jid = jid; this.name = name; this.ask = ask; this.subscription = subscription; this.groups = groups; } /** * Returns the JID associated with this item. The JID is the "key" in the * list of items that make up a roster. There can only be a single item per * JID in a roster. * * @return the JID associated with this item. */ public JID getJID() { return jid; } /** * Returns the nickname associated with this item. If no nickname exists, * <tt>null</tt> is returned. * * @return the nickname, or <tt>null</tt> if it doesn't exist. */ public String getName() { return name; } /** * Returns the ask state of this item. * * @return the ask state of this item. */ public Ask getAsk() { return ask; } /** * Returns the subscription state of this item. * * @return the subscription state of this item. */ public Subscription getSubscription() { return subscription; } /** * Returns a Collection of the groups defined in this item. If * no groups are defined, an empty Collection is returned. * * @return the groups in this item. */ public Collection<String> getGroups() { if (groups == null) { return Collections.emptyList(); } return groups; } public String toString() { StringBuffer buf = new StringBuffer(); buf.append("<item "); buf.append("jid=\"").append(jid).append("\""); if (name != null) { buf.append(" name=\"").append(name).append("\""); } buf.append(" subscrption=\"").append(subscription).append("\""); if (groups == null || groups.isEmpty()) { buf.append("/>"); } else { buf.append(">\n"); for (String group : groups) { buf.append(" <group>").append(group).append("</group>\n"); } buf.append("</item>"); } return buf.toString(); } } /** * Type-safe enumeration for the roster subscription type. Valid subcription types: * * <ul> * <li>{@link #none Roster.Subscription.none} -- the user does not have a * subscription to the contact's presence information, and the contact * does not have a subscription to the user's presence information. * <li>{@link #to Roster.Subscription.to} -- the user has a subscription to * the contact's presence information, but the contact does not have a * subscription to the user's presence information. * <li>{@link #from Roster.Subscription.from} -- the contact has a subscription * to the user's presence information, but the user does not have a * subscription to the contact's presence information. * <li>{@link #both Roster.Subscription.both} -- both the user and the contact * have subscriptions to each other's presence information. * <li>{@link #remove Roster.Subscription.remove} -- the user is removing a * contact from his or her roster. * </ul> */ public enum Subscription { /** * The user does not have a subscription to the contact's presence information, * and the contact does not have a subscription to the user's presence information. */ none, /** * The user has a subscription to the contact's presence information, but the * contact does not have a subscription to the user's presence information. */ to, /** * The contact has a subscription to the user's presence information, but the * user does not have a subscription to the contact's presence information. */ from, /** * Both the user and the contact have subscriptions to each other's presence * information. */ both, /** * The user is removing a contact from his or her roster. The user's server will * 1) automatically cancel any existing presence subscription between the user and the * contact, 2) remove the roster item from the user's roster and inform all of the user's * available resources that have requested the roster of the roster item removal, 3) inform * the resource that initiated the removal of success and 4) send unavailable presence from * all of the user's available resources to the contact. */ remove; } /** * Type-safe enumeration for the roster ask type. Valid ask types: * * <ul> * <li>{@link #subscribe Roster.Ask.subscribe} -- the roster item has been asked * for permission to subscribe to their presence but no response has been received. * <li>{@link #unsubscribe Roster.Ask.unsubscribe} -- the roster owner has asked * to the roster item to unsubscribe from it's presence but has not received * confirmation. * </ul> */ public enum Ask { /** * The roster item has been asked for permission to subscribe to their presence * but no response has been received. */ subscribe, /** * The roster owner has asked to the roster item to unsubscribe from it's * presence but has not received confirmation. */ unsubscribe; } }