jstl自定义标签防盗链

2019-11-09 13:48:06

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jstl自定义标签防盗链

*自定义标签的使用主要包括以下三个部分1.tagServlet代码设计2.tld文件配置3.jsp页面引用自定义标签

代码块

tagServlet代码如下：

@requires_authorizationpackage example;import java.io.IOException;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.jsp.JspException;import javax.servlet.jsp.PageContext;import javax.servlet.jsp.SkipPageException;import javax.servlet.jsp.tagext.SimpleTagSupport;public class tagFangDaoLian extends SimpleTagSupport{ PRivate String site; private String page; public void setSite(String site) { this.site = site; } public void setPage(String page) { this.page = page; } @Override public void doTag() throws JspException, IOException { PageContext pc = (PageContext) this.getJspContext(); HttpServletRequest request = (HttpServletRequest) pc.getRequest(); String referer = request.getHeader("referer"); HttpServletResponse response = (HttpServletResponse) pc.getResponse(); System.out.println(request.getContextPath()); if(referer==null||!referer.startsWith(site)){ //做出判断，如果为空或符合盗链链接，准备进入盗链者界面 if(page.startsWith(request.getContextPath())){ response.sendRedirect(page); }else if(page.startsWith("/")){ response.sendRedirect(request.getContextPath()+page); }else{ response.sendRedirect(request.getContextPath()+"/"+page); } throw new SkipPageException(); } }}

tld配置文件代码如下：

@requires_authorization<?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>showlist</short-name> <uri>/tag</uri><tag> <name>untheft</name> <tag-class>example.tagFangDaoLian</tag-class> <body-content>empty</body-content> <attribute> <name>site</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>page</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute></tag></taglib>

jsp页面调用如下：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib prefix="m" uri="/tag" %>** <m:untheft site="http://localhost" page="untheft.jsp"/>** <%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>My JSP 'main.jsp' starting page</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">  </head> <body> <h3>选项</h3> <a href="jsp/save.jsp">添加新员工</a> <a href="${pageContext.request.contextPath}/servlet/selectPageServlet?pageNum=1">查看所有员工</a> </body></html>