幾乎相同的 deal.jsp 代碼（index.jsp不變），在IDEA相同項目運行，結果卻不同，實在想不出來

時間 2019-11-12

標籤幾乎相同 deal.jsp deal jsp 代碼 index.jsp index 不變 idea 項目運行結果卻不實在出來欄目 JSP 简体版

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主要問題

幾乎相同的 deal.jsp 代碼（index.jsp不變），在IDEA相同項目相互運行，結果卻不同，實在想不出來html

主要項目

對應的IDEA JSP項目:6.9_2.zipjava

index.jsp:

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>顯示歷史、顯示添加留言功能</title>
    <link rel="stylesheet" type="text/css" href="word_index.css" />

    <script language="JavaScript">
        function ifNull(form_Msg){
            var userName = form_Msg.upload_UserName.value;
            var userMsg = form_Msg.upload_UserMsg.value;
            if (userName === "") {
                alert("留言人不能爲空");
                form_Msg.upload_UserName.focus();
                return false;
            }
            if (userMsg === "") {
                alert("留言內容不能爲空");
                form_Msg.upload_UserMsg.focus();
                return false;
            }
        }
    </script>
</head>
<body>
<span class="word_Msg">留言板</span><br><br>
<%

    if (session.isNew()){
        int number_person_index = 0;
        session.setAttribute("number_person",number_person_index);
    }

    int i;
    String[] message_index = (String[])session.getAttribute("message");
    int num = Integer.parseInt(session.getAttribute("number_person").toString());
    if (num != 0) {
        out.println("123213132");
        out.println("number_person: " + num + "<br><br>");
        for (i=0; i < num; i++) {
            out.println(message_index[i]);
        }
    }
%>
<br><hr>

<form action="deal.jsp" id="form_UploadMassage" name="form_UploadMassage" method="post" onSubmit="return ifNull(form_UploadMassage)">
    <span class="word_Msg">添加留言區域</span><br>
    留言人：<input type="text" id="upload_UserName" name="upload_UserName" title="留言人">
    留言內容：<textarea id="upload_UserMsg" name="upload_UserMsg" title="留言內容"></textarea>
    <input name="Submit" type="submit" value="提交留言">
    <input name="Submit2" type="reset" value="重置">
</form>
</body>
</html>

deal.jsp（正確可運行）:

<%@ page language="java" contentType="text/html; charset=utf-8"
         pageEncoding="utf-8"%>
<%
    request.setCharacterEncoding("utf-8");
    String userName_deal=request.getParameter("upload_UserName");   //獲取留言人
    String userMsg_deal=request.getParameter("upload_UserMsg"); //獲取留言內容
    String message_add="["+userName_deal+"]說："+userMsg_deal+"<br>"; //組合留言信息

    int i;
    int num = Integer.parseInt(session.getAttribute("number_person").toString());
    int num_add = num+1;
    String[] message_old = (String[])session.getAttribute("message");
    String[] message_new = new String[num_add+1];

    if(session.getAttribute("number_person")!=null){
        if (num > 0) {
            for (i=0; i<num; i++) {
                message_new[i] = message_old[i];
            }
        }
        message_new[num_add-1] = message_add;
    }
    session.setAttribute("number_person",num_add);
    session.setAttribute("message",message_new);    //將留言信息保存到session中
    response.sendRedirect("index.jsp");
%>

deal.jsp（錯誤不可運行）:

<%@ page language="java" contentType="text/html; charset=utf-8"
         pageEncoding="utf-8"%>
<%
    request.setCharacterEncoding("utf-8");
    String userName_deal = request.getParameter("upload_UserName");
    String userMsg_deal = request.getParameter("upload_UserMsg");
    String message_add = "["+userName_deal+"]說："+userMsg_deal+"<br>";   //組合留言信息

    int i;
    int num = Integer.parseInt(session.getAttribute("number_person").toString());
    int num_add = num+1;
    String[] message_old = (String[])session.getAttribute("message");
    String[] message_new = new String[num_add+1];

    if (session.getAttribute("number_person")!=null) {
        if (num > 0) {
            for (i=0; i<num; i++) {
                message_new[i] = message_old[i];
            }
        }
        message_new[num_add-1] = message_add;
    }
    session.setAttribute("number_person",num_add);
    session.setAttribute("massage",message_new);
    response.sendRedirect("index.jsp");
%>