• Java遇见HTML——JSP篇之JSP指令与动作元素


    一、include指令(如:<%@include file="..."%> )

    示例:

    Date.jsp

    1 <%@page import="java.text.SimpleDateFormat"%>
    2 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    3 <%
    4     Date d=new Date();
    5     SimpleDateFormat sf=new SimpleDateFormat("yyyy年MM月dd日");
    6     String s=sf.format(d);
    7     out.print(s);
    8 %>

    include.jsp

     1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
     2 <%
     3 String path = request.getContextPath();
     4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
     5 %>
     6 
     7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
     8 <html>
     9   <head>
    10     <base href="<%=basePath%>">
    11     
    12     <title>My JSP 'include.jsp' starting page</title>
    13     
    14     <meta http-equiv="pragma" content="no-cache">
    15     <meta http-equiv="cache-control" content="no-cache">
    16     <meta http-equiv="expires" content="0">    
    17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    18     <meta http-equiv="description" content="This is my page">
    19     <!--
    20     <link rel="stylesheet" type="text/css" href="styles.css">
    21     -->
    22 
    23   </head>
    24   
    25   <body>
    26     <h1>include指令</h1>
    27     <hr>
    28     <%@include file="Date.jsp" %> 
    29   </body>
    30 </html>

    运行界面:访问include.jsp界面

    二、include动作(如: <jsp:include page="..." flush="false">)

    示例:

     1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
     2 <%
     3 String path = request.getContextPath();
     4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
     5 %>
     6 
     7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
     8 <html>
     9   <head>
    10     <base href="<%=basePath%>">
    11     
    12     <title>My JSP 'include.jsp' starting page</title>
    13     
    14     <meta http-equiv="pragma" content="no-cache">
    15     <meta http-equiv="cache-control" content="no-cache">
    16     <meta http-equiv="expires" content="0">    
    17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    18     <meta http-equiv="description" content="This is my page">
    19     <!--
    20     <link rel="stylesheet" type="text/css" href="styles.css">
    21     -->
    22 
    23   </head>
    24   
    25   <body>
    26     <h1>include动作</h1>
    27     <hr>
    28     <jsp:include page="Date.jsp" flush="false"></jsp:include>
    29   </body>
    30 </html>

    运行结果:

    三、include指令与include动作的区别

    <jsp:include>动作在请求期间被执行,而include指令在编译期页面间被执行。

    页面内容经常变化时更适合使用<jsp:include>动作。

    页面内容不经常变化时更适合使用include指令

    <jsp:include>动作包含的是执行结果,而include指令包含的是文件内容。

    jsp:include这个其实就是:

    include指令:

    <%@ include %>编译后文件包括其所包含jsp的源代码;<jsp:include>编译后文件不包括,只写明所包含文件的名字,其和所包含文件之间是相对独立的存在。

    四、forward动作

    五、param动作

    示例:

    login.jsp

    dologin.jsp

    user.jsp

    运行结果:

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  • 原文地址:https://www.cnblogs.com/Qian123/p/5295903.html
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