(九)包含指令 (JSP学习第二天)
静态包含：<%@ include file="要包含的文件的路径">
定义三个要包含的文件info.html,info.jsp,info.inc
info.html文件内容：
<h1> <font color="red">info.html</font> </h1>
info.jsp文件内容:
<h1> <font color="green"><%="info.jsp"%></font> </h1>
info.inc文件内容：
<h1> <font color="yellow">info.inc</font> </h1>
使用静态包含三个文件：include_demo01.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%> <html> <head> <title>测试</title> </head> <body> <h1>静态包含</h1> <%@include file="info.html" %> <%@include file="info.jsp" %> <%@include file="info.inc" %> </body> </html>
动态包含:
<jsp:include page="包含的文件"/>
传递参数的：
<jsp:include page="包含的文件">
<jsp:param name="参数名称" value="参数内容"/>
.........
</jsp:include>
用动态包含三个文件：include_demo02.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%> <html> <head> <title>测试</title> </head> <body> <h1>动态包含</h1> <jsp:include page="info.html"/> <jsp:include page="info.jsp"/> <jsp:include page="info.inc"/> </body> </html>
定义包含文件,并传递参数 include_demo03.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%> <html> <head> <title>测试</title> </head> <body> <% String username="xiaoming"; %> <jsp:include page="receive_param.jsp"/> <jsp:param name="name" value="<%=username%>"/> <jsp:param name="info" value="ceshi"/> </body> </html>
接收传递的参数:receive_param.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%>
<html>
<head>
<title>测试</title>
</head>
<body>
<h1>参数一:<%=request.getParameter("name")%></h1>
<h2>参数二:<%=request.getParameter("info")%>
</body>
</html>
开发时用动态包含,可以避免一些不必要的错误,比如变量重复定义
例如:被包含的动态页include.jsp
<%
int x=10;
%>
<h1>include.jsp--<%=x%></h1>
静态包含处理页:include_demo04.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%> <html> <head> <title>测试</title> </head> <body> <% int x=100; %> <%@ include file="include.jsp"%> </body> </html>
运行时报错,是因为相同的变量重复定义!
动态包含处理页:include_demo05.jsp
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%> <html> <head> <title>测试</title> </head> <body> <% int x=100; %> <jsp:include page="include.jsp"/> </body> </html>
