实用jstl实现未登录时不能绕过登录界面的效果
package com.filter; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class StateFilter implements Filter { private ArrayList<String> list = new ArrayList(); @Override public void destroy() { // TODO 自动生成的方法存根 } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest)request; HttpServletResponse rep=(HttpServletResponse)response; HttpSession session = req.getSession(); String path1=req.getRequestURI(); String path2=req.getContextPath(); String target =path1.substring(path2.length()); if(list.contains(target)==false){ if(session.getAttribute("user")==null){ rep.sendRedirect("login.jsp"); } else{ chain.doFilter(req, rep); } } else{ chain.doFilter(req, rep); } } @Override public void init(FilterConfig cfg) throws ServletException { String val=cfg.getInitParameter("allowpage"); String[] arr=val.split(","); list.addAll(Arrays.asList(arr)); } }
package com.filter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class TestFilter implements Filter{ @Override public void destroy() { // TODO 自动生成的方法存根 } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // TODO 自动生成的方法存根 //HttpServletRequest req=(HttpServletRequest)request; //HttpServletResponse rep = (HttpServletResponse)response; request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); //response.getWriter().write("kaishi"); chain.doFilter(request, response); //response.getWriter().write("jieshu"); } @Override public void init(FilterConfig arg0) throws ServletException { // TODO 自动生成的方法存根 } }
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> <filter> <filter-name>testfilter</filter-name> <filter-class>com.filter.TestFilter</filter-class> </filter> <filter-mapping> <filter-name>testfilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <filter> <filter-name>loginfilter</filter-name> <filter-class>com.filter.StateFilter</filter-class> <init-param> <param-name>allowpage</param-name> <param-value>/login.jsp,/login</param-value> </init-param> </filter> <filter-mapping> <filter-name>loginfilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <display-name>Test0213am</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> </web-app>
login.jsp界面:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>1aasdasd</h1>
</body>
</html>
NewFile.jsp界面:
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<h2>JSP文件</h2>
</body>
</html>
地址栏输入任何地址都跳转到login.jsp界面(除了login这个界面是白名单)