开源大军中的一个无名小兵丁

package cn.itcast.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 javax.servlet.http.HttpSession;

import cn.itcast bean.User;

import cn.itcast.util.CookieUtil;

public class AutoLogonFilter implements Filter {

       public void destroy() {

       }

//保存cookie时的cookieName,与CookieUtil.java中的设置相同

       private final static String cookieDomainName = “cn.itcast”;

       public void doFilter(ServletRequest req, ServletResponse resp,

                     FilterChain chain) throws IOException, ServletException {

              HttpServletRequest request = (HttpServletRequest)req;

              HttpServletResponse response = (HttpServletResponse)resp;

              HttpSession session = request.getSession(true);

              User user = (User)session.getAttribute("user");

              //如果封装的user不为空,说明已经登陆,则继续执行用户的请求.下面的就不处理了

              if(user!=null){

                     chain.doFilter(request,response);

                     return;

              }

              //user为空，说明用户还没有登陆,就尝试得到浏览器传送过来的Cookie

              Cookie cookies[] = request.getCookies();

              String cookieValue = null;

              if(cookies!=null){

                     for(int i=0;i

                            if (cookieDomainName.equals(cookies[i].getName())) {

                                   cookieValue = cookies[i].getValue();

                                   break;

                            }

                     }

              }

              //如果cookieValue为空,也继续执行用户请求

              if(cookieValue==null){

                     chain.doFilter(request,response);

                     return;

              }

              //cookieValue不为空执行下面的方法,调用CookieUtil.java中的readCookieAndLogon方法

              try{

                     CookieUtil.readCookieAndLogon(cookieValue, request, response, chain);

              }catch(Exception e){

                     e.printStackTrace();

              }

       }

       public void init(FilterConfig arg0) throws ServletException {

       }

}

package cn.itcast.servlet;

/*

 * update 2007.09.23 by lyhapple

 * 检查用户登陆

 * */

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import cn.itcast.bean.User;

import cn.itcast.dao.UserDAO;

import cn.itcast.factory.DaoImplFactory;

import cn.itcast.util.CookieUtil;

public class CheckLogonServlet 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 {

              request.setCharacterEncoding("utf-8");

              String username = request.getParameter("username").trim();

              String password = CookieUtil.getMD5(request.getParameter("password"));

              String remeberMe = request.getParameter("remeberMe");

              HttpSession session = request.getSession(false);

              // 将接收到的用户名传递到UserDao的checkUser方法中,检查用户

              // 返回一个User类型的对象

              UserDAO ud = DaoImplFactory.getInstance();

              User user = ud.selectUserByUsername(username);

              if (user == null) {

                     request.setAttribute("checkUserError","");用户名不存在,请先注册

                     request.getRequestDispatcher("index.jsp").forward(request, response);

                     return;

              }

              if(!password.equals(user.getPassword())){

                     request.setAttribute("checkPasswordError","");密码输入错误,请重新输入

                     request.getRequestDispatcher("index.jsp").forward(request, response);

                     return;

              }

              //保存Cookie,这里调用了CookieUtil.java中的saveCookie方法，将上面的user对象作为参数传递

              if ("on".equals(remeberMe)) {

                     CookieUtil.saveCookie(user, response);

              }

              //在Session中保存用户信息，并转向用户的个人信息页面

              session.setAttribute("user", user);

              request.getRequestDispatcher("User/userInfo.jsp").forward(request,response);

       }

}