Question

我获取了表单信息，并用每个表单对象填充了一个arraylist。现在，我想将每个表单对象显示到一个名为displayEvent.jsp的新jsp上。但是，在displayEvent.jsp上，我将指向servlet的指针和方法设置为“ get”，并将“ action”更改为“ display”，但是我的servlet似乎无法识别该操作已更改。

displayEvent.jsp：

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


<!DOCTYPE html>
<html>
    <c:import url="/includes/header.html" />
    <c:import url="/includes/navigation.html" />
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
        <link rel="stylesheet" href="styles/main.css" type="text/css"/>
    </head>
    <body>
        <div class="float-box1">
            <h1>Nice Strike!</h1>
            <img src="https://usatftw.files.wordpress.com/2018/04/epa_italy_soccer_serie_a.jpg?w=1000&h=600&crop=1" alt="Bicycle Kick" height="500" width="500">
        </div>
        <div class="float-box">
            <h2>Reserved Field Times</h2>
            <c:forEach var="event" items="${eventList.events}"> 
                <tr align="center">
                    <td>${event.eventTitle}</td>
                    <td>${event.description}</td>
                    <td>${event.fieldNumber}</td>
                    <td>${event.date}</td>
                    <td>${event.startTime}</td>
                    <td>${event.stAMPM}</td>
                    <td>${event.endTime}</td>
                    <td>${event.etAMPM}</td> 
                </tr>
            </c:forEach>

            <form action="AddEventServlet" method="get">
                <input type="hidden" name="action" value="display">
            </form>

        </div>
        <div style="clear: both;"></div>
    </body>
    <footer>
        <p1><c:import url="/includes/footer.jsp" /></p1>
    </footer>
</html>

AddEventServlet.java：

public class AddEventServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response)
            throws ServletException, IOException {
        String url = "/index.jsp";

        HttpSession session = request.getSession();
        EventList eventList = new EventList();
        request.setAttribute("eventList", eventList);

        // get current action
        String action = request.getParameter("action");
        System.out.println(action);

        if (action == null) {
            action = "home";  // default action
        }

        if (action.equals("add")) {
            // get parameters from the request
            String eventTitle = request.getParameter("Event Title");
            String description = request.getParameter("Description");
            String fieldNumber = request.getParameter("Field Number");
            String date = request.getParameter("Date");
            String startTime = request.getParameter("Start Time");
            String stAMPM = request.getParameter("stAMPM");
            String endTime = request.getParameter("End Time");
            String etAMPM = request.getParameter("etAMPM");

            System.out.println("hello world");
            System.out.println(eventTitle);
            System.out.println(description);
            System.out.println(fieldNumber);
            System.out.println(date);
            System.out.println(startTime);
            System.out.println(stAMPM);
            System.out.println(endTime);
            System.out.println(etAMPM);

            // use regular Java class
            Event event = new Event(eventTitle, description, fieldNumber, date, startTime, stAMPM, endTime, etAMPM);
            eventList.addEvent(event);

            System.out.println(event.toString());

            // store the Event object in request and set URL
            request.setAttribute("event", event);
            url = "/enterEvent.jsp";

            request.setAttribute("successfulEntry", "Successfully entered event!");
            request.getRequestDispatcher(url)
                    .forward(request, response);
        }

        if (action.equals("home")) {
            url = "/index.jsp";     // the "index" page
            request.getRequestDispatcher(url)
                    .forward(request, response);

        } else if (action.equals("display")) {
            System.out.println("hello reeeee");
            String eventTitle = request.getParameter("eventTitle");
            String description = request.getParameter("description");
            String fieldNumber = request.getParameter("fieldNumber");
            String date = request.getParameter("date");
            String startTime = request.getParameter("startTime");
            String stAMPM = request.getParameter("stAMPM");
            String endTime = request.getParameter("endTime");
            String etAMPM = request.getParameter("etAMPM");

            request.getAttribute("eventList");
            if (eventList == null) {
                eventList = new EventList();
            }

            request.setAttribute("eventList", eventList);
            url = "/displayEvent.jsp";


            System.out.print(eventList);

            request.getRequestDispatcher(url)
                    .forward(request, response);
        }
    }

    @Override
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

}

Answer 1

<servlet>
 <servlet-name>AddEventServlet </servlet-name>
 <servlet-class>AddEventServlet </servlet-class>
</servlet>

您是否在web.xml上设置了映射属性？

即使在jsp中更改，“ Action”在servlet中也不会更改

1 个答案: