叨叨两句

1. ~

Filter

自动登录

1. 登录页面填写信息，提交后跳转至loginServlet
2. 调用service方法处理登录业务
3. 判断返回是否为空，若不为空，则说明登录成功
4. 如果登录成功，判断是否需要自动登录
5. 如果需要就将用户名和密码存储到cookie中，并通过response发送客户端
6. filter到cookie中获取用户名和密码
7. 调用service的方法，根据用户名和密码查询user对象
8. 将user对象存储到session中
9. 放行

public class LoginServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        try {            //1.获得用户名和密码            String username = request.getParameter("username");            String password = request.getParameter("password");                        //2.调用业务,进行登录            LoginService loginService = new LoginService();            User user = loginService.login(username,password);                        //3.判断用户是否为空            if(user != null){                //登录成功                //response.getWriter().print("Login Success...");                String auto = request.getParameter("auto");                                if(auto != null && "ok".equalsIgnoreCase(auto)){                    System.out.println("用户勾选了自动登录...");                    Cookie cookie = new Cookie("autoLogin", username+"-"+password);                    cookie.setPath(request.getContextPath());                    cookie.setMaxAge(60*60*24);                    response.addCookie(cookie);                    }                                                            request.getSession().setAttribute("user", user);                response.sendRedirect(request.getContextPath()+"/WEB01/index.jsp");            }else{                //登录失败                response.getWriter().print("Login Fail...");            }                    } catch (SQLException e) {            e.printStackTrace();            //登录失败            response.getWriter().print("Login Fail...");        }    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}