【1】html模板
<html>
<head><!-- base标签表示uri相对路径的基准路径 --><base href="http://localhost:8080/asite6/chapter6/ex6_11/visitor.html"/><title>html template</title><!-- meta 模拟响应消息头：Content-Type 表示内容类型 --> <meta http-equiv="Content-Type" content="text/html;charset=UTF-8"><!-- meta 模拟响应消息头：下面3个响应头都是为了禁用浏览器缓存，因为存在着浏览器兼容问题所以设置了3个响应头以覆盖所有浏览器 --><meta http-equiv="Expires" content="0"><meta http-equiv="Cache-Control" content="no-cache"><meta http-equiv="Pragma" content="no-cache">
</head>
<body><a href="chapter6/ex6_10/validate.jsp">访问validate.jsp页面</a>
</body>
</html>1）源码：
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib prefix="tangrong" uri="/validateTag" %>
<tangrong:validate/>
如果您看到了这些内容，说明本JSP页面已经正常执行完毕！<?xml version="1.0" encoding="UTF-8" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"version="2.0"><tlib-version>1.0</tlib-version><short-name>validateTag</short-name><uri>/validateTag</uri><tag><description>validate tag</description><name>validate</name><tag-class>ex6_8.ValidateTag</tag-class><body-content>empty</body-content></tag>
</taglib>
package ex6_8;import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;public class ValidateTag extends TagSupport { // 自定义标签处理器public int doEndTag() throws JspException {HttpServletRequest req = (HttpServletRequest) pageContext.getRequest();String referrer = req.getHeader("referer"); // 访问请求是从哪个页面链接过来的String sitePart = "http://" + req.getServerName(); // jsp页面所在服务器地址System.out.println("referrer = " + referrer);System.out.println("sitePart = " + sitePart);if (referrer != null && referrer.startsWith(sitePart)) {return EVAL_PAGE;} else {try {pageContext.getOut().write("对不起，您的访问方式不合法！");} catch (IOException e) {e.printStackTrace();}return SKIP_PAGE;}}
}
内部类)
)
