Cookie是实现记住用户名实例

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("
");
        out.print("用户名+value+"/>
");
        out.print("密码
");
        out.print("+check+"/>记住用户名
");
        out.print("
");
        out.print("");

    }

    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);
    }

}