Smack/documentation/messaging.html

109 lines
4.4 KiB
HTML

<html>
<head>
<title>Smack: Chat - Jive Software</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<div class="header">
Messaging using Chat and GroupChat
</div>
<div class="nav">
&laquo; <a href="index.html">Table of Contents</a>
</div>
<p>
Sending messages back and forth is at the core of instant messaging. Two classes
aid in sending and recieiving messages:
<ul>
<li> <tt>org.jivesoftware.smack.Chat</tt> -- used to send messages between two people.
<li> <tt>org.jivesoftware.smack.GroupChat</tt> -- used to join a chat room to send messages between many people.
</ul>
Both the Chat and GroupChat classes use the <tt>org.jivesoftware.smack.packet.Message</tt> packet
class to send messages. In certain circumstances, you may wish to bypass the higher-level
Chat and GroupChat classes to send and listen for messages directly.
</p>
<p class="subheader">
Chat
</p>
A chat creates a new thread of messgaes (using a thread ID) between two users. The
following code snippet demonstrates how to create a new Chat with a user and then send
them a text message:<p>
<div class="code"><pre>
<font color="gray"><i>// Assume we've created an XMPPConnection name "connection".</i></font>
Chat newChat = connection.createChat(<font color="green">"jsmith@jivesoftware.com"</font>);
newChat.sendMessage(<font color="green">"Howdy!"</font>);
</pre></div><p>
The <tt>Chat.sendMessage(String)</tt> method is a convenience method that creates a Message
object, sets the body using the String parameter, then sends the message. In the case
that you wish to set additional values on a Message before sending it, use the
<tt>Chat.createMessage()</tt> and <tt>Chat.sendMessage(Message)</tt> methods, as in the
following code snippet:<p>
<div class="code"><pre>
<font color="gray"><i>// Assume we've created an XMPPConnection name "connection".</i></font>
Chat newChat = connection.createChat(<font color="green">"jsmith@jivesoftware.com"</font>);
Message newMessage = newChat.createMessage();
newMessage.setBody(<font color="green">"Howdy!"</font>);
message.setProperty(<font color="green">"favoriteColor"</font>, <font color="green">"red"</font>);
newChat.sendMessage(newMessage);
</pre></div><p>
The Chat object allows you to easily listen for replies from the other chat participant.
The following code snippet is a parrot-bot -- it echoes back everything the other user types.<p>
<div class="code"><pre>
<font color="gray"><i>// Assume we've created an XMPPConnection name "connection".</i></font>
Chat newChat = connection.createChat(<font color="green">"jsmith@jivesoftware.com"</font>);
newMessage.setBody(<font color="green">"Hi, I'm an annoying parrot-bot! Type something back to me."</font>);
<b>while</b> (<b>true</b>) {
<font color="gray"><i>// Wait for the next message the user types to us.</i></font>
Message message = newChat.nextMessage();
<font color="gray"><i>// Send back the same text the other user sent us.</i></font>
newChat.sendMessage(message.getBody());
}
</pre></div><p>
The code above uses the <tt>Chat.nextMessage()</tt> method to get the next message, which
will wait indefinitely until another message comes in. There are other methods to wait
a specific amount of time for a new message, or you can add a listener that will be notified
every time a new message arrives.
<p class="subheader">
GroupChat
</p>
A group chat connects to a chat room on a server and allows you to send and receive messages
from a group of people. Before you can send or receive messages, you must join the room using
a nickname. The following code snippet connects to a chat room and sends a
message.<p>
<div class="code"><pre>
<font color="gray"><i>// Assume we've created an XMPPConnection name "connection".</i></font>
GroupChat newGroupChat = connection.createGroupChat(<font color="green">"test@jivesoftware.com"</font>);
<font color="gray"><i>// Join the gropu chat using the nickname "jsmith".</i></font>
newGroupChat.join(<font color="green">"jsmith"</font>);
<font color="gray"><i>// Send a message to all the other people in the chat room.</i></font>
newGroupChat.sendMessage(<font color="green">"Howdy!"</font>);
</pre></div><p>
In general, sending and receiving messages in a group chat works very similarly to
the <tt>Chat</tt> class. Method are also provided to get the list of the other
users in the room.<p>
<br clear="all" /><br><br>
<div class="footer">
Copyright &copy; Jive Software 2002-2003
</div>
</body>
</html>