jsp脚本和注释

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：

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--%>