问题
In short, I want ejabberd server to send some messages to a group of user clients.
the group of users may change. For example, the server send message to group 1, and then send different message to group 2.
In other words, how to make ejabberd server send messages to client? I know how to send message from client to client.
来源：https://stackoverflow.com/questions/30390720/ejabberd-server-broadcast-message