LoginServlet

package com.controller;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.RequestDispatcher;
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.model.bean.UserInfo;
import com.model.service.UserInfoService;

/**

• Servlet implementation class LoginServlet
  */
  public class LoginServlet extends HttpServlet {
  private static final long serialVersionUID = 1L;

  /**

  • @see HttpServlet#HttpServlet()
    */
    public LoginServlet() {
    super();
    // TODO Auto-generated constructor stub
    }

  /**

  • @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doPost(request,response);
    }

  /**

  • @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");

    String action=request.getParameter("flag");//先获取是否有flag 如果有 说明是自动登录
    if("auto".equals(action)){//如果action是auto 说明是自动登录请求 执行自动登录方法
    try {
    doAutoLogin(request,response);
    } catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    }
    }else{//如果不是 说明是没有自动登录请求 正常登陆
    doLogin(request,response);
    }

  }

  private void doLogin(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
  UserInfo user= new UserInfo();
  getParam(request,user);//获取表单中发来的数据的方法 并且将数据封装到（UserInfo）user中
  try {
  boolean flag=UserInfoService.getInstance().findUserPw(user);//先判断用户账号密码是否正确
  if(flag){//如果正确 下面看是否点击了自动登陆复选框
  //获取自动登录复选框的值
  String autologin=request.getParameter("autologin");
  if("1".equals(autologin)){//如果点击了复选框 那么向Cookie中 存入用户的用户名和密码
  //cookie中存储数据
  Cookie c=new Cookie("auto",user.getUsername()+","+user.getPassword());
  c.setMaxAge(606024);
  c.setPath("/");
  response.addCookie(c);//将数据加入浏览器额Cookie中
  }else{//如果没选择复选框 那么 清除cookie中的数据
  Cookie c=new Cookie("auto","");
  c.setMaxAge(0);
  c.setPath("/");
  response.addCookie(c);
  }
  response.sendRedirect("MainStation.jsp");//登陆成功后跳至主界面
  }else{//如果账号密码错误 则登陆失败 则请求转发 重新回到本界面
  String error="错误";
  request.setAttribute("error", error);

           RequestDispatcher rs=request.getRequestDispatcher("login.jsp");
           rs.forward(request, response);
       }
       
   } catch (SQLException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
   }
  

  }
  //自动登录方法
  private void doAutoLogin(HttpServletRequest request, HttpServletResponse response) throws SQLException, IOException, ServletException {

   Cookie[] cookie=request.getCookies();//获取浏览器Cookie数组
   for(Cookie c:cookie){                //遍历数组
       String name=c.getName();         //获取元素的name
       String value=c.getValue();       //获取元素的value
       if("auto".equals(name)){         //如果有auto的name 进行判断
           if(value!=null&&!"".equals(value)){     //如果value值不为空  向下执行
               String[] str=value.split(",");      //拆分其中的值
               String username=str[0];
               String password=str[1];
               UserInfo user=new UserInfo();       //获取值 将其封装
               user.setUsername(username);
               user.setPassword(password);
               boolean flag=UserInfoService.getInstance().findUserPw(user);//判断用户名密码是否正确
               if(flag){//如果正确  登陆成功 跳转至主界面
                   response.sendRedirect(request.getContentType()+"/MainStation.jsp");
               }else{//如果不正确 清除Cookie  请求转发  回到当前界面
                   //清除Cookie中的数据
                   Cookie coo=new Cookie("auto","");
                   coo.setMaxAge(0);
                   coo.setPath("/");
                   response.addCookie(coo);
                   
                   //登陆失败
                   request.setAttribute("error", "用户名或密码错误");
                   request.getRequestDispatcher("login.jsp").forward(request, response);
                   
               }
           }
       }
   }
  

  }

  private void getParam(HttpServletRequest request, UserInfo user) {
  user.setUsername(request.getParameter("username"));
  user.setPassword(request.getParameter("password"));

  }

}