java/srcPubnubApi/com/pubnub/api/PubnubCore.java
/**
     *
     * Listen for presence of subscribers on a channel
     *
     * @param channel
     *            Name of the channel on which to listen for join/leave i.e.
     *            presence events
     * @param callback
     *            object of sub class of Callback class
     * @exception PubnubException
     *                Throws PubnubException if Callback is null
     */
Listen for presence of subscribers on a channel
@param channel
Name of the channel on which to listen for join/leave i.e.
presence events
@param callback
object of sub class of Callback class
@exception PubnubException
Throws PubnubException if Callback is null
Listen for presence of subscribers on a channel @param channel Name of the channel on which to listen for join / leave i . e . presence events @param callback object of sub class of Callback class @exception PubnubException Throws PubnubException if Callback is null
public void presence(String channel, Callback callback)
            throws PubnubException {
        Hashtable args = new Hashtable(2);
        args.put("channels", new String[] {channel + PRESENCE_SUFFIX});
        args.put("callback", callback);
        subscribe(args);
    }
public void presence ( String channel , Callback callback ) throws PubnubException { Hashtable args = new Hashtable ( 2 ) ; args . put ( "channels" , new String [ ] { channel + PRESENCE_SUFFIX } ) ; args . put ( "callback" , callback ) ; subscribe ( args ) ; }
Listen for presence of subscribers on a channel
 @param channel
            Name of the channel on which to listen for join/leave i.e.
Listen for presence of subscribers on a channel @param channel Name of the channel on which to listen for join / leave i . e .