JSP复习整理基本语法

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最基础的整理。。

一、语句声明

<%@ 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>JSP整理</title>
</head>
<body>
<%!int n = 1; %>
<%--声明一个变量 --%>
<%! public int count(){
	return n++;
}
/* 声明一个方法  */	%>
<%
//jsp程序代码

out.println("You had kown it...");
out.println("Welcome......");
%>
<br>
<%="You are the "+count()+"个来到时光之旅的神。。" %>
<br>
}
<%=(new java.util.Date()).toLocaleString()%>
</body>
</html>

 技术分享

二、方法声明

<%@ 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>计算圆的面积</title>
</head>
<body>
<p>输入可爱的圆的半径吧:</p>
<form action="DecMethod.jsp" method="get" name="form">
<input type="text" name="radius">
<input type = "submit" name="submit" value="计算" >
</form>

<%!
double area(double r){
	return Math.PI * r * r;
}

double perimeter(double r){
	return Math.PI*2*r;
}

%>

<%
String s=request.getParameter("radius");
if(s!=null){
	try{
		double r;
		r=Double.parseDouble(s);
		%>
		
		<p>圆的面积为:<%= area(r)%>
		<p>圆的周长为:<%= perimeter(r) %><%
	}catch(Exception e){
		out.println(e.getMessage());
	}
}
%>
</body>
</html>

 输入半径-》x显示结果:

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三、forward

login.jsp

<%@ 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>JSP:Forward</title>
</head>
<body bgcolor=#B39EA5>
<form method=get action=checklogin.jsp>
  <table>
     <tr>
        <td>输入用户名:</td>
        <td><input type=text name=name
              value=<%=request.getParameter("user") %>></td>
     </tr>
     <tr>
         <td>输入密码:</td>
         <td><input type=password name=password></td>
     </tr>
     <tr colspan=2>
         <td><input type=submit value=login></td>
     </tr>
  </table>
</form>
</body>
</html>

 checklogin.jsp

<%@ 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>checklogin</title>
</head>
<body  bgcolor=#B39EA5>
<%

    String name = request.getParameter("name");
    String password = request.getParameter("password");
    //if success    forward--->success.jsp
    //else    forward------>login.jsp
    if(name.equals("HaiXiao")&&password.equals("123456")){
    	%>
    	<jsp:forward page="success.jsp">
    	   <jsp:param name="user" value="<%=name %>"/>
    	   </jsp:forward>
    	   <%
    }
    else{
    	%>
    	<jsp:forward page="login.jsp">
    	    <jsp:param name="user" value="<%=name%>"/>
    	    </jsp:forward>
    	    <%
    }
%>
</body>
</html>

 success.jsp

<%@ 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>success</title>
</head>
<body bgcolor=#B39EA5>
登陆成功
<br>welcome!!!
<%=request.getParameter("user") %>
</body>
</html>

 结果:

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 先写到这了。。

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