jsp技术（可以嵌套java代码，也擅长写HTML代码）！
jsp本质其实就是一个servlet类
jsp脚本
<%j ava代码 %> 1）----- 内部的java代码翻译到service方法的内部
<%=java变量或表达式%> ----- 会被翻译成service方法内部out.print()
<%!java代码%> ---- 会被翻译成servlet的成员的内容
jsp注释：
Html注释：<!--注释内容-->
java注释：//单行注释 /*多行注释*/
jsp注释：<%--注释内
<%@ 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>
</head>
<body>
<!--这是HTML注释-->
<%
//这是java单行注释
/*这是java多行注释*/
int i=100;
System.out.print(i);
%>
<%--这jsp注释 --%>
<%=i %>
<%! String str="起于凡而非凡"; %>
<%=str %>
</body>
</html>
jsp指令三个：
page指令：<%@ page 属性名1= "属性值1" 属性名2= "属性值2" ...%>
include指令：格式：<%@ include file="被包含的文件地址"%>
taglib指令：格式：<%@ taglib uri="标签库地址" prefix="前缀"%>
<%@page import="java.util.ArrayList"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" session="false" errorPage="Error.jsp"%>
<!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>
</head>
<body>
<%
int y=1/0;
/*如果Session为false时则body里面报错，必须重新创建session对象，不是false时默认是true*/
HttpSession session=request.getSession();
session.setAttribute("goods","naiping");
%>
<%
ArrayList<String> arr=new ArrayList<String>();
%>
</body>
</html>
<%@ 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>
</head>
<body>
<%@ include file="header.jsp" %>
这是内容
<%@ include file="footer.jsp" %>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" isErrorPage="true"%>
<!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>
</head>
<body>
这是一个处理错误页面
</body>
</html>
<%@ 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>
</head>
<body>
这是尾部
</body>
</html>
容--%>