问题描述
聊天信息显示页面：show.jsp信息处理页面：transaction.jsp隐页面输入页面：input.jsp有一个输入框message，一个提交按钮使用application对象发送消息：当我运行这个程序时(刚刚登陆到聊天页面)，发现页面在一直在刷新，一直的在show页面输出null值！下面是代码show.jsp<html><head></head><body><%request.setCharacterEncoding("utf-8");if(application.getAttribute("message")!=null&&application.getAttribute("message").equals("")){//获取所有用户的聊天信息ArrayList<String>list=(ArrayList<String>)application.getAttribute("message");StringBufferbuffer=newStringBuffer();for(Stringstring:list){buffer.append(string+"<br>");}out.print(buffer.toString());}if(application.getAttribute("message")==null){}%></body></html>transact.jsp<html><head><title></title></head><body><%request.setCharacterEncoding("utf-8");Stringcurrname=(String)session.getAttribute("currUser");//获取名字Stringmessage=(String)request.getAttribute("message");message=currname+":"+message;ArrayList<String>list=(ArrayList<String>)application.getAttribute("message");if(list==null){list=newArrayList<String>();}list.add(message);application.setAttribute("message",list);response.sendRedirect("chatRoom.jsp");%></body></html>