Cookie是实现记住用户名实例

来源：互联网发布：京东校招java面试编辑：程序博客网时间：2024/05/16 11:28

Cookie是实现记住用户名实例

记住用户名的功能，登入成功后，给响应消息头添加用户名的Cookie信息，在登入页面时，加载cookie信息，通过cookie获取用户名信息，写在输入框中。

SimpleLoginServlet(简单的登入页面)：

@WebServlet({ "/SimpleLoginServlet", "/simple/login" })public class SimpleLoginServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    public SimpleLoginServlet() {        super();    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("utf-8");        response.setContentType("text/html;charset=utf-8");        PrintWriter out = response.getWriter();        String value = "";        String check="checked='checked'";        Cookie[] cookies = request.getCookies();        if(cookies!=null ){            for (int i = 0;i < cookies.length; i++) {                if ("username".equals(cookies[i].getName())) {                    value = cookies[i].getValue();                    System.out.println(value);                }            }            value = "value='"+value+"'";        }        out.print("<form action='"+request.getContextPath()+"/simple/login/success' method='post'>");        out.print("用户名<input type='text' name='username' "+value+"/><br/>");        out.print("密码<input type='password' name='password'/><br/>");        out.print("<input type='checkbox' name='check' "+check+"/>记住用户名<br/>");        out.print("<input type='submit' value='登入'/><br/>");        out.print("</form>");    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

LoginSuccessServlet(登入成功页面)

@WebServlet({ "/LoginSuccessServlet", "/simple/login/success" })public class LoginSuccessServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    public LoginSuccessServlet() {        super();    }    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("utf-8");        response.setContentType("text/html;charset=utf-8");        PrintWriter out = response.getWriter();        String username = request.getParameter("username");        String password = request.getParameter("password");        String check = request.getParameter("check");        Cookie cookie = new Cookie("username", username);        cookie.setPath(request.getContextPath());        if ("tuhao".equals(username) && "123456".equals(password)) {            //check部位null,表示记住用户名了            if(check!=null){                cookie.setMaxAge(5*60);                response.addCookie(cookie);                out.println("登入成功，已经记住用户名");            }else {                cookie.setMaxAge(0);                response.addCookie(cookie);                out.print("不记住用户名");            }        }else {            cookie.setMaxAge(0);            response.addCookie(cookie);            out.print("清除用户名");        }    }    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

0 0