sendRedirect()
response和request一样都是jsp内置对象，request是获取用户的请求，response处理用户请求。sendRedirect()函数的作用是重定向网页，向浏览器发送一个特殊的Header，然后由浏览器来做重定向，转到指定的页面。下面我将创建四个页面，首先是sex.jsp，有一个下拉列表和提交按钮确定，选择“男”，就跳转到male.jsp，选择“女”就跳转到female.jsp，中间通过sex_action.jsp进行重定向
<!-- sex.jsp -->
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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>Sex Select's 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">
</head>
<body><form action="<%=basePath%>c03/sex_action.jsp" method="post"><select name="sex"><option>男</option><option>女</option></select><button type="submit">提交</button></form>
</body>
</html>
<!-- sex_action.jsp -->
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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 'sex_action.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">
</head>
<body><% request.setCharacterEncoding("UTF-8");String sex = request.getParameter("sex");out.println(sex);if("男".equals(sex)) {response.sendRedirect("male.jsp");return;}else if("女".equals(sex)) {response.sendRedirect("female.jsp");return;}%>
</body>
</html>