dwr聊天室程序chat.rar

package com.lhq; import java.util.ArrayList; import java.util.Collection; import java.util.HashSet; import java.util.List; import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; import org.directwebremoting.ScriptSession; import org.directwebremoting.ServerContext; import org.directwebremoting.ServerContextFactory; import org.directwebremoting.WebContextFactory; import org.directwebremoting.proxy.dwr.Util; /** * 处理聊天相关 * * @author lhq * */ public class ChatManager { /** 保存当前在线用户列表 */ public static List<User> users = new ArrayList<User>(); /** * 更新在线用户列表 * @param username 待添加到列表的用户名 * @param flag 是添加用户到列表,还是只获得当前列表 * @param request * @return 用户userid */ public String updateUsersList(String username, boolean flag, HttpServletRequest request) { User user = null; if (flag) { // 这里取会话(HttpSession)的id为用户id user = new User(request.getSession().getId(), username); //保存用户到列表 users.add(user); //将用户id和页面脚本session绑定 this.setScriptSessionFlag(user.getUserid()); } //获得DWR上下文 ServletContext sc = request.getSession().getServletContext(); ServerContext sctx = ServerContextFactory.get(sc); //获得当前浏览 index.jsp 页面的所有脚本session Collection sessions = sctx.getScriptSessionsByPage("/chat/index.jsp"); Util util = new Util(sessions); //处理这些页面中的一些元素 util.removeAllOptions("users"); util.addOptions("users", users, "username"); util.removeAllOptions("receiver"); util.addOptions("receiver", users,"userid","username"); if(!flag){ return null; } return user.getUserid(); } /** * 将用户id和页面脚本session绑定 * @param userid */ public void setScriptSessionFlag(String userid) { WebContextFactory.get().getScriptSession().setAttribute("userid", userid); } /** * 根据用户id获得指定用户的页面脚本session * @param userid * @param request * @return */ @SuppressWarnings("unchecked") public ScriptSession getScriptSession(String userid, HttpServletRequest request) { ScriptSession scriptSessions = null; Collection<ScriptSession> sessions = new HashSet<ScriptSession>(); sessions.addAll(ServerContextFactory.get(request.getSession().getServletContext()) .getScriptSessionsByPage("/chat/index.jsp")); for (ScriptSession session : sessions) { String xuserid = (String) session.getAttribute("userid"); if (xuserid != null && xuserid.equals(userid)) { scriptSessions = session; } } return scriptSessions; } /** * 发送消息 * @param sender 发送者 * @param receiverid 接收者id * @param msg 消息内容 * @param request */ public void send(String sender,String receiverid,String msg,HttpServletRequest request){ ScriptSession session = this.getScriptSession(receiverid, request); Util util = new Util(session); util.setStyle("showMessage", "display", ""); util.setValue("sender", sender); util.setValue("msg", msg); } }