用AJAX+J2EE实现一个网上会议室系统(1)(3)

package com.easyjf.chat.action;
public class ChatAction extends AbstractCmdAction {
　private ChatService chatRoom;
　public Object doBefore(WebForm form, Module module) {
// TODO Auto-generated method stub
if(chatRoom==null)chatRoom=ChatService.get((String)form.get("cid"));
　return super.doBefore(form, module);
　}
　public Page doInit(WebForm form, Module module) {
// TODO Auto-generated method stub 
　return doMain(form,module);
　} 
　//用户登录进入会议室
　public Page doMain(WebForm form, Module module) { 
if(chatRoom!=null){
　ChatUser user=getChatUser(); 
　if(!chatRoom.join(user))form.addResult("msg","不能加入房间，可能是权限不够！");
　form.addResult("chatRoom",chatRoom);
　form.addResult("user",user);
}
else
{
　form.addResult("msg","会议未启动或者会议室不存在！");
} 
return module.findPage("main");
　} 
　//处理用户发言信息
　public Page doSend(WebForm form, Module module) { 
if(chatRoom==null)return new Page("err","/err.html","thml");//返回会议室不存在的错误
Chat chat=(Chat)form.toPo(Chat.class);
chat.setCid(chatRoom.geneId());
chatRoom.talk(chat);
return doRecive(form,module);
　} 
　//用户接收发言信息
　public Page doRecive(WebForm form, Module module) { 
　if(chatRoom==null)return new Page("err","/err.html","thml");//返回会议室不存在的错误
　String lastReadId=CommUtil.null2String(form.get("lastReadId"));
　//System.out.println(lastReadId);
　form.addResult("list", chatRoom.getNewestMsg(getChatUser(),lastReadId)); 
　return module.findPage("msgList");
　}
　//用户刷新会议状态信息
　public Page doLoadConfig(WebForm form, Module module) { 
if(chatRoom==null)return new Page("err","/err.html","thml");//返回会议室不存在的错误 
form.addResult("userList", chatRoom.getUsers());
form.addResult("talkerList", chatRoom.getTalkers());
return module.findPage("config");
　}
　//用户退出
　public Page doExit(WebForm form, Module module) { 
　if(chatRoom==null)return new Page("err","/err.html","thml");//返回会议室不存在的错误
　hatRoom.exit(getChatUser());
　form.addResult("msg","退出成功");
　ActionContext.getContext().getSession().removeAttribute("chatUser");
　return new Page("msg","/chat/xmlMsg.xml",Globals.PAGE_TEMPLATE_TYPE);
}

function newXMLHttpRequest() {
　var xmlreq = false;
　if (window.XMLHttpRequest) { 
xmlreq = new XMLHttpRequest();
　} else if (window.ActiveXObject) { 
try { 
　xmlreq = new ActiveXObject("Msxml2.XMLHTTP");
　} catch (e1) { 
　try { 
　xmlreq = new ActiveXObject("Microsoft.XMLHTTP");
　} catch (e2) { 
　}
　}
}
return xmlreq;
}
//处理返回信息 
//xmlHttp返回值,
//method:方法名 方法必须带一个参数如doRecive(xNode);
function handleAjaxResult(req,method) { 
　return function () { 
if (req.readyState == 4) { 
　if (req.status == 200) {
// 将载有响应信息的XML传递到处理函数
var objXMLDoc=new ActiveXObject("Microsoft.XMLDOM");
objXMLDoc.loadXML(req.responseText); 
eval("if(objXMLDoc.firstChild)"+method+"(objXMLDoc.firstChild.nextSibling);"); 
　} else { 
//alert("HTTP error: "+req.status);
}
　}
}
　}
　//执行客户端Ajax命令
　//url 数据post地址
　//postData 发送的数据包
　//handleMethod　处理返回的方法
　function executeAjaxCommand(url,postData,handleMethod)
　{
var req = newXMLHttpRequest(); 
req.onreadystatechange =handleAjaxResult(req,handleMethod); 
req.open("PO　ST", url, true); 
req.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
req.setRequestHeader("charset","utf-8"); 
req.send(postData);
　}
　//用户发言
unction doSend()
{
　if(!check())return false;
　var msg=EditForm.content.value;
　var reciver=EditForm.reciver.value; 
　var url="/chat.ejf?easyJWebCommand=send&cid="+roomId+"&lastReadId="+lastReadId;
　var postData="sender="+myName+"&reciver="+reciver+"&content="+msg;
　clearTimeout(reciveTime);
　executeAjaxCommand(url,postData,"recive");
　EditForm.content.value="";
}
//接收发言信息
function doRecive()
{ 
　var reciver=EditForm.reciver.value; 
　var url="/chat.ejf?easyJWebCommand=recive&cid="+roomId+"&lastReadId="+lastReadId;
　executeAjaxCommand(url,"","recive"); 
}
//处理接收到的发言信息
function recive(list)
{
　var id=""; 
　for(var oNode=list.firstChild;oNode;oNode=oNode.nextSibling) // 依次分析每个节点
　{
chatContent.innerHTML+=showMsg(oNode);
id=oNode.getAttribute("cid");
　}
　if(id!="") lastReadId=id; 
　chatContent.scrollTop=chatContent.scrollHeight;
　reciveTime=setTimeout("doRecive();",5000); 
}