javaWeb之jsp（一）输出hello world
out.println()的使用
此处定义的str为jsp局部变量
<%@ 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>
<%
String str = "hello world";
out.println(str);
%>
</body>
</html>
其中< body >体内使用<% %>包裹的为jsp代码
jap声明的使用
声明的变量为全局变量
<%@ 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>
<%!
String str = "hello world";
%>
<%
out.println(str);
%>
</body>
</html>
jsp表达式
jsp表达式是符合java语法的表达式，它可以将java表达式的值作为字符串直接输出
<%@ 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>
jsp表达式<%="hello word" %>
<%!
String str = "hello world";
%>
<%
//String str = "hello world";
out.println(str);
%>
</body>
</html>
