login.jsp

介绍一个聊天室的编程方法,展示了一个网络程序的基本结构

<%@ page contentType="text/html; charset=GB2312"
	 import="java.util.Date"%>
<%
	String gestnam = request.getParameter("txtnam");
	String gestsex = request.getParameter("txtsex") ;
	session.setAttribute("nam0", gestnam); 
	session.setAttribute("sex0",gestsex);
	int i = 0;	
	int talker = 0;
	Object talk = null;
	Object visitnam = null;
	Object visitsex = null;
	String talkerstr=(String)application.getAttribute("talker0");	
	if(talkerstr == null)
	{
		application.setAttribute("talker0", "1");
	}
	else
	{
		talker = Integer.parseInt(talkerstr);		
		application.setAttribute("talker0", String.valueOf(talker+1));
	}

	String sentencestr = (String) session.getAttribute("sentence0");
	int sentence = Integer.parseInt(sentencestr);
	if(talker == 0)
	{
		for(i = 1; i <= sentence; i++)application.setAttribute("talk"+i,"");
		for(i=1;i<=sentence;i++)application.setAttribute("visitnam"+i,"");
		for(i=1;i<=sentence;i++)application.setAttribute("visitsex"+i,"");
	}
	else
	{
		for(i = sentence; i >= 2; i--)
		{
			talk = application.getAttribute("talk"+(i - 1));	
			application.setAttribute("talk"+i, talk);
			visitnam = application.getAttribute("visitnam"+(i - 1));	
			application.setAttribute("visitnam"+i, visitnam);
			visitsex = application.getAttribute("visitsex"+(i - 1));	
			application.setAttribute("visitsex"+i, visitsex);
		}	
	}
	application.setAttribute("visitnam1", gestnam);
	application.setAttribute("visitsex1", gestsex);

	String tking = null;
	Date dat = new Date(); 
	String year = String.valueOf(dat.getYear() + 1900);
	String month = String.valueOf(dat.getMonth() + 1);
	String day = String.valueOf(dat.getDate());
	String hour = String.valueOf(dat.getHours());
	String minute = String.valueOf(dat.getMinutes());
	String second = String.valueOf(dat.getSeconds());
	String tim = year + "/" + month + "/" + day + " "
	      + hour + ":" + minute + ":" + second;
	tking = "<tr><th colspan = 6 bgcolor = lightgrey align=left>欢迎"
	      	+gestnam+gestsex+"光临   "+tim+"</th></tr>";
	application.setAttribute("talk1", tking);	
	response.sendRedirect("frame.jsp"); 
%>