JSP的内置对象
在JSP页面中不需要获取创建，可以直接使用的对象
jsp一共有9个内置对象
Request
Response
out：字节输出流对象，可以将数据输出到页面上，和Response.getWriter（）类似
Response.getWriter（）和out.writer（）的区别
在tomcat服务器真正给客户端做出响应之前，会先找到Response缓存数据，在找out缓存区数据
Response.getWriter（）数据输出到永远在out.write（）之前
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%
System.out.println("hello jsp");
int i =5;
String contextPath = request.getContextPath();
out.print(contextPath);
%>
<%!
int i = 3;
%>
<%="hello" %>
<%
response.getWriter().write("response");
%>
</body>
</html>
jsp案例_改造cookie案例
<%@ page import="java.net.URLDecoder" %>
<%@ page import="java.util.Date" %>
<%@ page import="java.text.SimpleDateFormat" %>
<%@ page import="java.net.URLEncoder" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<%
Cookie[] cookies = request.getCookies();
boolean flag = false;
if (cookies !=null && cookies.length>0){
for (Cookie cookie : cookies) {
String name = cookie.getName();
if ("lastTime".equals(name)){
flag = true;
String value = cookie.getValue();
System.out.println("解码前："+value);
value = URLDecoder.decode(value, "utf-8");
System.out.println("解码后："+value);
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
String format = sdf.format(date);
System.out.println("编码前："+format);
format = URLEncoder.encode(format, "utf-8");
System.out.println("编码后："+format);
cookie.setValue(format);
cookie.setMaxAge(60*60*24*30);
response.addCookie(cookie);
%>
<h1>欢迎回来，您上次访问时间为<%=value%></h1>
<%
break;
}
}
}
if (cookies == null || cookies.length == 0 || flag == false){
Date date = new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
String format = simpleDateFormat.format(date);
System.out.println("编码前"+format);
format = URLEncoder.encode(format,"utf-8");
System.out.println("编码后"+format);
Cookie cookie = new Cookie("lastTime",format);
cookie.setValue(format);
cookie.setMaxAge(60*60*24*30);
response.addCookie(cookie);
%>
<h1>您好，欢迎您首页访问成功</h1>
<span></span>
<%
}
%>
</body>
</html>
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标签：format,value,案例,jsp,cookie,Response,out From： https://www.cnblogs.com/12-12-12/p/16587075.html