package org.getahead.dwrdemo.chat;import java.util.Collection;import java.util.LinkedList;import org.directwebremoting.WebContext;import org.directwebremoting.WebContextFactory;import org.directwebremoting.proxy.dwr.Util;import org.directwebremoting.util.Logger;/** * @author Joe Walker [joe at getahead dot ltd dot uk] */public class JavaChat{    /**     * @param text The new message text to add     */    public void addMessage(String text)    {        // Make sure we have a list of the list 10 messages        if (text != null && text.trim().length() > 0)        {            messages.addFirst(new Message(text));            while (messages.size() > 10)            {                messages.removeLast();            }        }        WebContext wctx = WebContextFactory.get();        String currentPage = wctx.getCurrentPage();        // Clear the input box in the browser that kicked off this page only        Util utilThis = new Util(wctx.getScriptSession());        utilThis.setValue("text", "");        // For all the browsers on the current page:        Collection sessions = wctx.getScriptSessionsByPage(currentPage);        Util utilAll = new Util(sessions);        // Clear the list and add in the new set of messages        utilAll.removeAllOptions("chatlog");        utilAll.addOptions("chatlog", messages, "text");    }    /**     * The current set of messages     */    private LinkedList messages = new LinkedList();    /**     * The log stream     */    protected static final Logger log = Logger.getLogger(JavaChat.class);}