有一个 old question 与此有关，但当时 Smack 不支持此 XMPP 扩展 (XEP-0333)。在 discourse.igniterealtime.org 中也有一个 question，但它没有答案，它的重点是询问他们何时会支持 xep-0333 扩展。
目前 Smack 在Experimental Smack Extensions 支持它，您可以找到代码here。
到目前为止，我一直在寻找示例、指南或如何使用此扩展程序，但没有成功。 我也尝试挖掘代码，希望能找到一些关于如何使用的 javadoc，但也没有成功。
这个问题的目标是获取如何在 smack 4.x.x 中使用它的 sn-p 代码
【问题讨论】：
更新：等待 PR 代码审查以更新以下代码。
回答我自己的问题：
正如我所说，Smack 库对 XEP-0333 具有实验性支持，在尝试将其与版本 4.2 和 4.3.0-rc1 一起使用后，我发现需要改进 XEP-0333 以使其像 IncomingChatMessageListener 或 ChatStateListener 一样工作。
此外，我无法使其仅使用 OutgoingChatMessageListener 和 IncomingChatMessageListener 接口工作，因为它们在内部检查 <message> 是否有 <body> 标记（因为 xmpp 协议规则），但该规则不适用XEP-0333：
当接收者发送一个聊天标记时，它应该确保消息节只包含聊天标记子元素和可选的（在适当的时候）一个线程子元素。自然，中间实体可能会在路由或传递接收消息时向消息添加其他扩展元素，例如延迟传递 (XEP-0203) 中指定的元素。
所以我所做的是按照ChatManager（版本2）和ChatStateManager的架构和行为改进ChatMarkersManager类。
以下代码是改进后的代码（我仍然需要 Smack 库人员的反馈），但它可以正常工作：
public final class ChatMarkersManager extends Manager {
private static final Map<XMPPConnection, ChatMarkersManager> INSTANCES = new WeakHashMap<>();
// @FORMATTER:OFF
private static final StanzaFilter FILTER = new NotFilter(new StanzaExtensionFilter(ChatMarkersElements.NAMESPACE));
private static final StanzaFilter CHAT_STATE_FILTER = new NotFilter(new StanzaExtensionFilter(ChatStateManager.NAMESPACE));
private static final StanzaFilter MESSAGE_FILTER = new OrFilter(
MessageTypeFilter.NORMAL_OR_CHAT,
MessageTypeFilter.GROUPCHAT
);
private static final StanzaFilter INCOMING_MESSAGE_FILTER = new AndFilter(
MESSAGE_FILTER,
new StanzaExtensionFilter(ChatMarkersElements.NAMESPACE)
);
// @FORMATTER:ON
private final Set<IncomingChatMarkerMessageListener> incomingListeners = new CopyOnWriteArraySet<>();
private final AsyncButOrdered<Chat> asyncButOrdered = new AsyncButOrdered<>();
private ChatMarkersManager(XMPPConnection connection) {
super(connection);
connection.addStanzaInterceptor(new StanzaListener() {
@Override
public void processStanza(Stanza packet)
throws
SmackException.NotConnectedException,
InterruptedException,
SmackException.NotLoggedInException {
Message message = (Message) packet;
if (shouldDiscardMessage(message)) {
return;
}
if (message.getBodies().isEmpty()) {
return;
}
// if message already has a chatMarkerExtension, then do nothing,
if (!FILTER.accept(message)) {
return;
}
// otherwise add a markable extension,
message.addExtension(new ChatMarkersElements.MarkableExtension());
}
}, MESSAGE_FILTER);
connection.addSyncStanzaListener(new StanzaListener() {
@Override
public void processStanza(Stanza packet)
throws
SmackException.NotConnectedException,
InterruptedException,
SmackException.NotLoggedInException {
final Message message = (Message) packet;
if (shouldDiscardMessage(message)) {
return;
}
EntityFullJid fullFrom = message.getFrom().asEntityFullJidIfPossible();
EntityBareJid bareFrom = fullFrom.asEntityBareJid();
final Chat chat = ChatManager.getInstanceFor(connection()).chatWith(bareFrom);
List<IncomingChatMarkerMessageListener> listeners;
synchronized (incomingListeners) {
listeners = new ArrayList<>(incomingListeners.size());
listeners.addAll(incomingListeners);
}
final List<IncomingChatMarkerMessageListener> finalListeners = listeners;
asyncButOrdered.performAsyncButOrdered(chat, new Runnable() {
@Override
public void run() {
for (IncomingChatMarkerMessageListener listener : finalListeners) {
if (ChatMarkersElements.MarkableExtension.from(message) != null) {
listener.newMarkableMessage(message);
} else if (ChatMarkersElements.ReceivedExtension.from(message) != null) {
listener.newReceivedMessage(message);
} else if (ChatMarkersElements.DisplayedExtension.from(message) != null) {
listener.newDisplayedMessage(message);
} else if (ChatMarkersElements.AcknowledgedExtension.from(message) != null) {
listener.newAcknowledgedMessage(message);
}
}
}
});
}
}, INCOMING_MESSAGE_FILTER);
ServiceDiscoveryManager.getInstanceFor(connection).addFeature(ChatMarkersElements.NAMESPACE);
}
/**
* Get the singleton instance of ChatMarkersManager.
*
* @param connection
* @return the instance of ChatMarkersManager
*/
public static synchronized ChatMarkersManager getInstanceFor(XMPPConnection connection) {
ChatMarkersManager chatMarkersManager = INSTANCES.get(connection);
if (chatMarkersManager == null) {
chatMarkersManager = new ChatMarkersManager(connection);
INSTANCES.put(connection, chatMarkersManager);
}
return chatMarkersManager;
}
/**
* Register a IncomingChatMarkerMessageListener. That listener will be informed about new
* incoming markable messages.
*
* @param listener IncomingChatMarkerMessageListener
* @return true, if the listener was not registered before
*/
public boolean addIncomingChatMarkerMessageListener(IncomingChatMarkerMessageListener listener) {
synchronized (incomingListeners) {
return incomingListeners.add(listener);
}
}
/**
* Unregister a IncomingChatMarkerMessageListener.
*
* @param listener IncomingChatMarkerMessageListener
* @return true, if the listener was registered before
*/
public boolean removeIncomingChatMarkerMessageListener(IncomingChatMarkerMessageListener listener) {
synchronized (incomingListeners) {
return incomingListeners.remove(listener);
}
}
public void markMessageAsReceived(String id, Jid to, Jid from, String thread)
throws
SmackException.NotConnectedException,
InterruptedException {
Message message = createMessage(id, to, from, thread);
message.addExtension(new ChatMarkersElements.ReceivedExtension(id));
sendChatMarkerMessage(message);
}
public void markMessageAsDisplayed(String id, Jid to, Jid from, String thread)
throws
SmackException.NotConnectedException,
InterruptedException {
Message message = createMessage(id, to, from, thread);
message.addExtension(new ChatMarkersElements.DisplayedExtension(id));
sendChatMarkerMessage(message);
}
public void markMessageAsAcknowledged(String id, Jid to, Jid from, String thread)
throws
SmackException.NotConnectedException,
InterruptedException {
Message message = createMessage(id, to, from, thread);
message.addExtension(new ChatMarkersElements.AcknowledgedExtension(id));
sendChatMarkerMessage(message);
}
private Message createMessage(String id, Jid to, Jid from, String thread) {
Message message = new Message();
message.setStanzaId(id);
message.setTo(to);
message.setFrom(from);
message.setThread(thread);
return message;
}
private void sendChatMarkerMessage(Message message) throws SmackException.NotConnectedException, InterruptedException {
connection().sendStanza(message);
}
/**
* From XEP-0333, Protocol Format: The Chat Marker MUST have an 'id' which is the 'id' of the
* message being marked.
*
* @param message to be analyzed.
* @return true if the message contains a stanza Id.
* @see <a href="http://xmpp.org/extensions/xep-0333.html">XEP-0333: Chat Markers</a>
*/
private boolean shouldDiscardMessage(Message message) {
if (StringUtils.isNullOrEmpty(message.getStanzaId())) {
return true;
}
if (!CHAT_STATE_FILTER.accept(message)) {
ExtensionElement extension = message.getExtension(ChatStateManager.NAMESPACE);
String chatStateElementName = extension.getElementName();
ChatState state;
try {
state = ChatState.valueOf(chatStateElementName);
return !(state == ChatState.active);
} catch (Exception ex) {
return true;
}
}
return false;
}
/**
* Returns true if Chat Markers is supported by the server.
*
* @return true if Chat Markers is supported by the server.
* @throws SmackException.NotConnectedException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NoResponseException
* @throws InterruptedException
*/
public boolean isSupportedByServer()
throws SmackException.NoResponseException, XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException {
return ServiceDiscoveryManager.getInstanceFor(connection())
.serverSupportsFeature(ChatMarkersElements.NAMESPACE);
}
}
interface 很简单：
public interface IncomingChatMarkerMessageListener {
void newMarkableMessage(Message message);
void newReceivedMessage(Message message);
void newDisplayedMessage(Message message);
void newAcknowledgedMessage(Message message);
}
目前我没有使用Chat 对象，所以我没有通过接口传递它，但可以轻松添加它。其实我想能够处理Chat和MultiChat。
这可以与 XEP-0085 一起使用，正如 8.5 Interaction with Chat States 中的文档所建议的那样。
就像我在它工作之前所说的那样，遵循协议规则，但我有一些我无法回答的问题，我希望从 Smack 库人员那里得到一些反馈：D
【讨论】：