jsp - forward指令

时间：2023-03-09 07:59:24
jsp - forward指令

　　forward指令 既可以指向静态的html页面,也可以转发到动态的jsp页面,并可以保留先前请求的参数.

　　例如,在web中新建一个Jsp_src.jsp的jsp页面:

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

    <base href="<%=basePath%>">

    <title>原始页面</title>

	<meta http-equiv="pragma" content="no-cache">

	<meta http-equiv="cache-control" content="no-cache">

	<meta http-equiv="expires" content="0">

	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

	<meta http-equiv="description" content="This is my page">

	<!--

	<link rel="stylesheet" type="text/css" href="styles.css">

	-->

  </head>

  <body>

    原始页面. <br>

    <jsp:forward page="jsp_target.jsp"></jsp:forward>

  </body>

</html>

然后让页面Jsp_src.jsp转到jsp_target.jsp页面,jsp_target.jsp页面的代码为:

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

    <base href="<%=basePath%>">

    <title>jsp目标页面</title>

	<meta http-equiv="pragma" content="no-cache">

	<meta http-equiv="cache-control" content="no-cache">

	<meta http-equiv="expires" content="0">

	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

	<meta http-equiv="description" content="This is my page">

	<!--

	<link rel="stylesheet" type="text/css" href="styles.css">

	-->

  </head>

  <body>

    目标页面主体. <br>

    <jsp:forward page="jsp_target2.jsp"></jsp:forward>

  </body>

</html>

然后,再次在jsp_target.jsp页面中转到新的jsp页面jsp_target2.jsp,代码为:

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

    <base href="<%=basePath%>">

    <title>jsp目标页面2</title>

	<meta http-equiv="pragma" content="no-cache">

	<meta http-equiv="cache-control" content="no-cache">

	<meta http-equiv="expires" content="0">

	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

	<meta http-equiv="description" content="This is my page">

	<!--

	<link rel="stylesheet" type="text/css" href="styles.css">

	-->

  </head>

  <body>

    目标页面主体2. <br>

    req-char:<%=request.getCharacterEncoding() %>

   name=<%=request.getParameter("name") %>

  </body>

</html>

　　往浏览器中输入请求url: http://localhost:8080/ServletJSP/forward/Jsp_src.jsp?name=hi

可以看到,浏览器中请求地址依然不变,但内容也变为jsp_target2.jsp的页面的内容,而且,请求的参数name仍然可以保留.

相关文章