Question

我有一个应用程序，每周显示一个时间表。所有约会都存储为数据库条目。我使用类（ScheduleCells）来管理这些条目并将它们存储在bean（ScheduleCellbean）中并返回一个二维ArrayList。在我的index.jsp中，我有以下代码来检索此ArrayList并填写计划。在index.jsp中，我向servlet发送请求。

的index.jsp：

<script type="text/javascript">
    fillSchedule = function (w) {

        var xhr = new XMLHttpRequest();
        xhr.open("POST", "schedule?w=" + w);
        xhr.send();

        <%
            int i;
            int j;
            int w = 0;

            if (session.getAttribute("w") != null) {
               w = (Integer) session.getAttribute("w");
            }

            ScheduleCells sc = new ScheduleCells();

             for (i = 0; i < 9; i++) {

                 for (j = 0; j < 5; j++) {

                     ScheduleCellBean cell = sc.getCellByHDW(i + 1, j + 1, w);

                         if (cell.getExists()) {
        %>

        createNewAppointment(<%= j%>, <%= i%>,
            "<%= cell.getSubject_scheduled_subjectabbr()%>",
            "<%= cell.getUser_scheduled_userabbr()%>",
            "<%= cell.getScheduled_groupname()%>");

        <% }}}%>

    };

    fillSchedule(7);

</script>

ScheduleCellbean：

public class ScheduleCellBean extends ScheduleCells {

    private boolean exists = false; 
    private String scheduled_id;
    private String scheduled_date;
    private String scheduled_hour;
    private String user_scheduled_firstname;
    private String user_scheduled_lastname;
    private String user_scheduled_username;
    private String user_scheduled_password;
    private String user_scheduled_userabbr;
    private String user_scheduled_subjectname;
    private String user_scheduled_subjectabbr;
    private String scheduled_groupname;
    private String subject_scheduled_subjectname;
    private String subject_scheduled_subjectabbr;
    private String scheduled_datetimerequest;
    private String user_request_firstname;
    private String user_request_lastname;
    private String user_request_username;
    private String user_request_password;
    private String user_request_userabbr;
    private String user_request_subjectname;
    private String user_request_subjectabbr;

    //Getters And Setters.

}

ScheduleCellServlet.jsp：

@WebServlet(name = "ScheduleCell", urlPatterns = {"/schedule"})
public class ScheduleCellServlet extends HttpServlet {

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException, SQLException {

        HttpSession session = request.getSession();
        session.setAttribute("w", Integer.parseInt(request.getParameter("w")));

     }

    //Default HTTP Servlet functions.

}

一切正常，但因为我在那里使用servlet会有延迟，这会导致计划似乎无法加载，但在刷新时，会话属性会通过并且正确计划已加载。因此，我所做的任何更改（例如fillSchedule(8)）仅在我重新加载页面时发生。但我喜欢互动的时间表，这意味着用户可以选择一周，并立即弹出该周的正确时间表。我看到的时间表在我选择的内容方面缺乏落后，当我重新阅读页面时，我所选择的时间表是可见的，但同时第7周的时间表再次被加载，但只有当我再次加载时才能看到页。

我的问题是：我怎样才能以不必（手动）刷新页面的方式实现这一目标？

提前感谢您的帮助！

Answer 1

自动刷新您的jsp页面以获得新的响应。

代码段：

<%@ page import="java.io.*,java.util.*" %>
<html>
<head>
<title>Auto Refresh Header Example</title>
</head>
<body>
<center>
<h2>Auto Refresh Header Example</h2>
<%
   // Set refresh, autoload time as 5 seconds
   response.setIntHeader("Refresh", 5);
   // Get current time
   Calendar calendar = new GregorianCalendar();
   String am_pm;
   int hour = calendar.get(Calendar.HOUR);
   int minute = calendar.get(Calendar.MINUTE);
   int second = calendar.get(Calendar.SECOND);
   if(calendar.get(Calendar.AM_PM) == 0)
      am_pm = "AM";
   else
      am_pm = "PM";
   String CT = hour+":"+ minute +":"+ second +" "+ am_pm;
   out.println("Crrent Time: " + CT + "\n");
%>
</center>
</body>
</html>

使用JSP无延迟地加载计划的更好方法

1 个答案: