HttpServletResponse

1．response的运行流程

1．通过response设置响应行

设置响应行的状态码

setStatus(int sc)

解决页面输出中文乱码问题

response.setContentType("text/html;charset=UTF-8");

重定向
response.sendRedirect("/WEB02/Servlet02");

计数

	public void init() throws ServletException {
		//定义计数器
		int sum=0;
		//获取ServletContext对象
		ServletContext context=getServletContext();
		//存值
		context.setAttribute("sum", sum);
		
	}

js计数器

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="/WEB02/js/jquery-3.4.1.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {  
    function jump(count) {  
        window.setTimeout(function(){  
            count--;  
            if(count > 0) {  
                $('#second').html(count);  
                jump(count);  
            } else {  
                location.href="https://www.baidu.com";  
            }  
        }, 1000);  
    }  
    jump(5);  
}); 
</script>
</head>
<body>
	恭喜你注册成功，
	<span id="second" style="color: red">5</span>
	秒后跳转，如不跳转请点击
	<a href="https://www.baidu.com">这里</a>
</body>
</html>