1.防止用户盗链使用网站页面,可以判断Request.setHeader("referer"),链接中referer.startsWith(site) 是否以网站网址开始,否.跳转到网站首页,继续访问.是,直接访问...,控制自定义标签类RefererTag.java
package cn.itcast.web.tag; 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 RefererTag 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 { //看来访问者是从哪个页面来的 PageContext pageContext = (PageContext)this.getJspContext(); HttpServletRequest request = (HttpServletRequest) pageContext.getRequest(); String referer = request.getHeader("referer"); //http://www.sina.com/index.html //判断 if(referer==null || !referer.startsWith(site)){ HttpServletResponse response = (HttpServletResponse) pageContext.getResponse(); String webroot = request.getContextPath(); //day11_example if(page.startsWith(webroot)){ response.sendRedirect(page); }else{ response.sendRedirect(webroot + page); } //重定向后，控制保护的页面不要执行 throw new SkipPageException(); } } }
2.需要配置tld描述一把 自定义标签
<?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"> <description>A tag library exercising SimpleTag handlers.</description> <tlib-version>1.0</tlib-version> <short-name>SimpleTagLibrary</short-name> <uri>/itcast</uri> <tag> <name>referer</name> <!-- 为标签处理器类配一个标签名 --> <tag-class>cn.itcast.web.tag.RefererTag</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>
3.在JSP页面中调用 自定义标签 代码,防止用户盗链
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@taglib uri="/itcast" prefix="itcast"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <itcast:referer site="http://localhost:8080/" page="/index.jsp"/> <html> <head> <title>防盗链</title> </head> <body> 凤姐日记 </body> </html>