import org.jivesoftware.smack.chat.ChatMessageListener; //导入依赖的package包/类
private void fireNewChatState(Chat chat, ChatState state) {
    for (ChatMessageListener listener : chat.getListeners()) {
        if (listener instanceof ChatStateListener) {
            ((ChatStateListener) listener).stateChanged(chat, state);
        }
    }
}
 

import org.jivesoftware.smack.chat.ChatMessageListener; //导入依赖的package包/类
@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);

    if(result.equals("connected")){
        try {
            ConnectedMessage();

            pb_progressbar.setVisibility(View.GONE);
            ll_chat_window.setVisibility(View.VISIBLE);

            mChatmanager = mChatmanager.getInstanceFor(mConnection);
            friendJID = (EntityJid) JidCreate.from(friendID);
            mChat = mChatmanager.createChat(friendJID, new ChatMessageListener() {
                public void processMessage(org.jivesoftware.smack.chat.Chat chat, Message message) {

            // receiving the chat message from the support executive
                    if(!message.getBody().trim().equals("")){
                        mChatFunctionModel = new Chat();
                        mChatFunctionModel.setGotMessage(message.getBody());
                        mChatFunctionModel.setGotTime(new Date().getTime());
                        mChatFunctionModel.setSentMessage("");
                        chatsList.add(mChatFunctionModel);

                        runOnUiThread(new Runnable() {
                            public void run() {
                                mAdapter.notifyDataSetChanged();
                                mRecyclerView.smoothScrollToPosition(chatsList.size());
                                et_msgToBeSent.setFocusable(true);
                            }
                        });
                    }
                }
            });
        } catch (XmppStringprepException e) {
            e.printStackTrace();
        }
    }
    else{
        cannotConnectMessage();
    }

}
 

import org.jivesoftware.smack.chat.ChatMessageListener; //导入依赖的package包/类
/**
 * Returns a new Chat for sending private messages to a given room occupant.
 * The Chat's occupant address is the room's JID (i.e. [email protected]/nick). The server
 * service will change the 'from' address to the sender's room JID and delivering the message
 * to the intended recipient's full JID.
 *
 * @param occupant occupant unique room JID (e.g. '[email protected]/Paul').
 * @param listener the listener is a message listener that will handle messages for the newly
 * created chat.
 * @return new Chat for sending private messages to a given room occupant.
 */
public Chat createPrivateChat(String occupant, ChatMessageListener listener) {
    return ChatManager.getInstanceFor(connection).createChat(occupant, listener);
}