} } }

    屌丝成长之路——应用过滤器实现主动登录

    添加时间:2013-5-14 点击量:

    应用过滤器实现主动登录


    一、主动登录实现道理。


      (1)当用户勾选“记住暗码”时,先登录,然后把账号暗码记录到客户端的Cookie中,下次接见随便率性页面的时辰应用过滤器从客户端的Cookie中获取账号暗码进行登录,最后把Cookie时候刷新一遍。


      (2)当用户不勾选“记住暗码”时,先登录,然后把Cookie从客户端中烧毁。


    二、主动登录简单案例。


      登录的Servlet:



    package com.servlet;
    

    import java.io.IOException;

    import javax.servlet.ServletException;
    import javax.servlet.http.Cookie;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    import com.service.UserService;

    public class LoginServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
    doPost(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
    //获取登录页面的属性
    String userName=request.getParameter(userName);
    String passWord
    =request.getParameter(passWord);
    String autoLogin
    =request.getParameter(autoLogin);
    //实例化本身定义的登录Service类
    UserService loginService=new UserService();
    boolean flag=loginService.login(userName, passWord);
    if(flag){//登录成功履行该语句块
    if(autoLogin!=null&&!autoLogin.equals(null)){//若是勾选了“记录暗码”,把账号暗码存到客户端Cookie中
    Cookie c1=new Cookie(userName,userName);
    Cookie c2
    =new Cookie(passWord,passWord);
    c1.setMaxAge(
    6060);
    c2.setMaxAge(
    6060);
    response.addCookie(c1);
    response.addCookie(c2);
    }
    else{//如何不勾选“记录暗码”则把客户端的Cookie调换掉,并设置生活生计周期为0
    Cookie c1=new Cookie(userName,null);
    Cookie c2
    =new Cookie(passWord,null);
    c1.setMaxAge(
    0);
    c2.setMaxAge(
    0);
    response.addCookie(c1);
    response.addCookie(c2);
    }
    request.getSession().setAttribute(
    userName, userName);
    request.getRequestDispatcher(
    index.jsp).forward(request, response);
    }
    else{
    response.sendRedirect(
    login.jsp);
    }
    }
    }




    过滤器:



    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.Cookie;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    import com.service.UserService;

    public class LoginFilter implements Filter {

    public void destroy() {
    // TODO Auto-generated method stub

    }

    public void doFilter(ServletRequest arg0, ServletResponse arg1,
    FilterChain arg2)
    throws IOException, ServletException {
    HttpServletRequest request
    =(HttpServletRequest) arg0;
    HttpServletResponse response
    =(HttpServletResponse) arg1;
    String userName
    =(String) request.getSession().getAttribute(userName);//获取Session的值
    String passWord=null;
    if(userName==null){//若是未登录,获取客户端Cookie,并登录
    Cookie[] cookies=request.getCookies();
    if(cookies!=null){//获取客户端Cookie
    for(Cookie c:cookies){
    if(c.getName().equals(userName)){
    userName
    =c.getValue();
    }
    if(c.getName().equals(passWord)){
    passWord
    =c.getValue();
    }
    }
    }
    if(userName!=null&&passWord!=null){//如何账号暗码获取成功,则进行登录
    UserService loginService=new UserService();
    boolean flag=loginService.login(userName, passWord);
    if(flag){//登录成功刷新客户端Cookie
    Cookie c1=new Cookie(userName,userName);
    Cookie c2
    =new Cookie(passWord,passWord);
    c1.setMaxAge(
    6060);
    c2.setMaxAge(
    6060);
    response.addCookie(c1);
    response.addCookie(c2);
    request.getSession().setAttribute(
    userName, userName);
    }
    }
    }
    arg2.doFilter(request,response);
    }

    public void init(FilterConfig arg0) throws ServletException {
    // TODO Auto-generated method stub

    }
    }




    设备文件:



    <?xml version=1.0 encoding=UTF-8?>
    
    <web-app version=2.5
    xmlns
    =http://java.sun.com/xml/ns/javaee
    xmlns:xsi
    =http://www.w3.org/2001/XMLSchema-instance
    xsi:schemaLocation
    =http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd
    >
    <display-name></display-name>

    <filter>
    <filter-name>login</filter-name>
    <filter-class>com.filter.LoginFilter</filter-class>
    </filter>
    <filter-mapping>
    <filter-name>login</filter-name>
    <url-pattern>/</url-pattern>
    </filter-mapping>

    <servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>com.servlet.LoginServlet</servlet-class>
    </servlet>

    <servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/login</url-pattern>
    </servlet-mapping>
    <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    </web-app>




    login.jsp页面:



    <%@ page language=java import=java.util. pageEncoding=UTF-8%>
    

    <!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN>
    <html>
    <head>
    <title>My JSP login.jsp starting page</title>
    </head>

    <body>
    <form action=login method=post>
    <table>
    <tr>
    <td>用户名:</td>
    <td><input type=text name=userName /></td>
    </tr>
    <tr>
    <td>暗码:</td>
    <td><input type=password name=passWord /></td>
    </tr>
    <tr>
    <td></td>
    <td><input type=checkbox name=autoLogin value=auto>记住暗码</td>
    </tr>
    <tr>
    <td colspan=2 align=center>
    <input type=submit name=submit value=登录 />
    </td>
    </tr>
    </table>
    </form>
    </body>
    </html>



    index.jsp页面:



    <%@ page language=java import=java.util. pageEncoding=UTF-8%>
    

    <!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN>
    <html>
    <head>
    <title>My JSP index.jsp starting page</title>
    </head>

    <body>
    登录成功,迎接¥{sessionScope.userName}的到来
    </body>
    </html>


    我所有的自负皆来自我的自卑,所有的英雄气概都来自于我的软弱。嘴里振振有词是因为心里满是怀疑,深情是因为痛恨自己无情。这世界没有一件事情是虚空而生的,站在光里,背后就会有阴影,这深夜里一片寂静,是因为你还没有听见声音。—— 马良《坦白书》
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