Jsp重定向（response.sendRedirect()）和转发(request.getRequestDispatcher().forward(request,r)的差别 

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="sun.awt.RepaintArea"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'check_login.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
  	<%
  		request.setCharacterEncoding("utf-8");
  		String uname = request.getParameter("username");
  		String pwd = request.getParameter("password");
  		
  		if("sa".equals(uname) && "123".equals(pwd)){
  			//response.sendRedirect("welcome.jsp");
  			request.getRequestDispatcher("welcome.jsp").forward(request,response);
  		}else{
  			response.sendRedirect("login.jsp");
  		}
  	%>
  
  </body>
</html>


差别1：request.getRequestDispatcher().forward()是转发。是在同一个请求里。
response.sendRedirect()是重定向，因此放在request里的数据不会被传过去。

差别2：浏览器的地址栏变化。转发地址栏不会发生变化。重定向会发生变化。


posted @ 2018-02-04 08:26  yjbjingcha  阅读(209)  评论(0)    收藏  举报