Question

以下是我的要求

Login.html页面和用户名和密码文本字段，格式为
Login.html - ＆gt;提交btn - ＆gt;调用LoginServlet。
LoginServlet - ＆gt;来自DB的验证用户
成功 - ＆gt;调用DashboardServlet和DashboardServlet - ＆gt;致电Dashboard.html。
如何在Dashboard.html上阅读响应对象[我在这里从DashboardServlet传递用户名]。
如果在步骤4中失败 - > LoginServlet将调用Login.html - ＆gt;再次如何阅读此页面上的响应对象，让我说我要提醒（用户身份验证失败）

LogingServlet

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    System.out.println("I am in doPost of LoginServlet");
    String userName = request.getParameter("username");
    String passWord = request.getParameter("password");

    if(LoginDao.validate(userName, passWord))
    {
        HttpSession session=request.getSession();  
        if(session.isNew())
           {
            //New session creation
              session=request.getSession(true);
           }
            else
            {
               session = request.getSession(false);
            }

         //setting attribute on session
         session.setAttribute("userName",userName);
         //send request to Welcome.jsp page
         //response.sendRedirect("/Dashboard.html");
         response.sendRedirect("/zmcwebadmin/dashBoardServlet");
         response.getWriter().write(String.valueOf(userName));
         System.out.println("I have connected to DB");
    }

    else
    {
        //response.sendRedirect("error.html");
        String data = "User name and password do not match";
        response.setContentType("text/plain");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write(data);
        /*RequestDispatcher rd = request.getRequestDispatcher("Loginpage.html"); -- This solution works
        rd.forward(request, response);*/
        //response.sendRedirect("Loginpage.html");
        request.setAttribute("error", "Unknown login, try again");
        response.sendRedirect("/zmcwebadmin/html/Login.html");
        //doGet(request, response);

        System.out.println("I have not connected to server");
       }
      }

DashBoardServlet

    /**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
 *      response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    // TODO Auto-generated method stub


    System.out.println("I am in doGet of dashBoardServlet");
    //New writing on 19th March where initial control given to servlet

        HttpSession session = request.getSession(false); 
        if(session.getAttribute("userName") == null) //session is not created
            response.sendRedirect("/zmcwebadmin/html/LoginPage.html");
        else
            response.sendRedirect("/zmcwebadmin/html/Dashboard.html");
}

/**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
 *      response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    // TODO Auto-generated method stub

    System.out.println("I am in doPost of dashBoardServlet");
    String scannerState = request.getParameter("scannerState");
    System.out.println("Dashboard servlet called, scannerState: " + scannerState);
    System.out.println("I am in dashBoardServlet");
    ZebraDbDao zebraDbDao = new ZebraDbDao();
    List<Scanner> scannerList;

    try {
        scannerList = zebraDbDao.getScannerDetail(scannerState);
        System.out.println("I got the scanner list");
        String json = new Gson().toJson(scannerList);
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write(json);
    } catch (SQLException e) {

        e.printStackTrace();
    } // online scanner
}

Dashboard.html

   <script>

  function changeLogoutImage() {
    var image = document.getElementById('logoutbtn'); /* function for logout image*/
    if (image.src.match("_selected")) {
        image.src = "../Images/logout_deselected.png";
    } else {
        image.src = "../Images/logout_selected-18.png";
    }
}

   $(document).ready(function(){ 
   $('#form_logout').submit(function()  
  {
    $form = $(this);
$.post($form.attr('action'), $form.serialize(),  function(responseText)  {
$('#usenameText').text(responseText);                                    
        });
        return false;                                                            
    });
});

 </head>
 <body background="../Images/zebra_background.jpg">
 <div id="header"> ZMC Server <img src="../Images/zebra_logo.png" width=150px height=50px
        style="float: right;  padding-top:15px;">

    <form id="form_logout" action="/zmcwebadmin/logoutServlet" method=post>

        <input type="image" class="logbuttonformat"
                 id="logoutbtn"
                src="../Images/logout_deselected.png" 
                onclick="changeLogoutImage()" alt="submit">
    </form>
    <img id="changepas" src="../Images/change_pswrd_deselected.png"
        onclick="window.location.href='../html/ChangePassword.html'"
         style="float: right"> 
         <font
        style="color: #ffb911; font-size: 9.3pt; font-family: 'Roboto(Medium)', sans-serif; float: right; padding: 6px">
        USERNAME </font> 
        <img id="usernammeicon" onclick="changeUserImage()"
        src="../Images/username_icon.png" style="float: right">
</div>
</body>
</html>

从servlet读取响应到html页面

0 个答案: