Java jsp页面下拉列表主标题默认行为

在管理摘要页面中编辑条目时，“主标题”字段默认为“操作”，添加新条目时可以 输入，但在编辑此字段（即未来计划）中具有不同内容的现有计划时不确定，该字段随后被改写为“操作”。这在Firefox和Chrome中都会发生

那么，为什么单击“编辑”按钮时，“主标题”下拉列表默认为“操作”。我不希望它默认为“操作”，而是需要它加载原始的“主标题”选项，无论它是“操作”还是“未来计划”

代码如下：

      <%@ page contentType="text/html; charset=iso-8859-1" language="java" import="java.sql.*" errorPage="" %>
<%
/* New MSR Template */
String scriptName = "ad_summary.jsp";
String nextPage = "#";
String prevPage = "#";
%>
<%@include file="includes/getSession.jsp" %>
<%@include file="includes/getGlobal.jsp" %>
<%

String action="";   
if (request.getParameter("action") !=null) {action = (String)request.getParameter("action");}
String rowid="";
if (request.getParameter("rowid") !=null) {rowid = (String)request.getParameter("rowid");}
String service="";
if (request.getParameter("service") !=null) {service = (String)request.getParameter("service");}

String mainHeading="";
if (request.getParameter("mainHeading") !=null) {mainHeading = (String)request.getParameter("mainHeading");}

if (!mainHeading.equals("")){
  mainHeading = Eacute(mainHeading);
}

String serviceName="";
if (request.getParameter("serviceName") !=null) {serviceName = (String)request.getParameter("serviceName");}
String description="";
if (request.getParameter("description") !=null) {description = (String)request.getParameter("description");}

if (!description.equals("")){
  description = Eacute(description);
}

String submit="";   
if (request.getParameter("submit") !=null) {submit = (String)request.getParameter("submit");}
String cancel="";   
if (request.getParameter("cancel") !=null) {cancel = (String)request.getParameter("cancel");}
String itemOrder="1";
if (request.getParameter("itemOrder") !=null) {itemOrder = (String)request.getParameter("itemOrder");}
int whichOrder = Integer.valueOf(itemOrder);

boolean ErrorsDetected = false;
java.util.ArrayList<String> ErrorList = new java.util.ArrayList<String>();

Connection conn = null;
PreparedStatement statement = null;
PreparedStatement statement1 = null;
PreparedStatement statement2 = null;
ResultSet resultset = null;
boolean resultsetHasData = false;

Context initContext = new InitialContext();
Context envContext  = (Context)initContext.lookup("java:/comp/env");
DataSource ds = (DataSource)envContext.lookup("jdbc/LocalMSR");
conn = ds.getConnection();

String sqlString = "";

//Pick up maximum value 
int MaxValue = 0;
sqlString = "SELECT MAX(item_order)";
sqlString = sqlString + " FROM msr_summary_notices ";
sqlString = sqlString + " WHERE (year = "+MSR_YEAR+") AND (month ="+MSR_MONTH_NUMBER+") AND (topic NOT IN ('Notices','Services'))";

statement = conn.prepareStatement(sqlString);
resultset = statement.executeQuery();
resultsetHasData = resultset.next();

if (resultsetHasData){
 MaxValue = Integer.valueOf(resultset.getString("MAX(item_order)")!=null?resultset.getString("MAX(item_order)"):"0");   
}

resultset.close();
statement.close();

if (action.equals("move_up")){
  action="add";

  if (whichOrder != 1){
    int CurrentOrder = whichOrder;
    int NewOrder = whichOrder - 1;
    String sqlString1 = "UPDATE msr_summary_notices set item_order = "+String.valueOf(NewOrder)+" WHERE item_order = "+String.valueOf(CurrentOrder);
    String sqlString2 = "UPDATE msr_summary_notices set item_order = "+String.valueOf(CurrentOrder)+" WHERE item_order = "+String.valueOf(NewOrder)+" AND absid <>"+rowid;
    statement1 = conn.prepareStatement(sqlString1);
    int RowsAffected1 = (statement1.executeUpdate());
    statement1.close();
    statement2 = conn.prepareStatement(sqlString2);
    int RowsAffected2 = (statement2.executeUpdate());
    statement2.close();
  }else{
    // Do nothing coz you can move up above 1  
  }
}

if (action.equals("move_down")){
  action="add";

  if (whichOrder != MaxValue){
    int CurrentOrder = whichOrder;
    int NewOrder = whichOrder + 1;
    String sqlString1 = "UPDATE msr_summary_notices set item_order = "+String.valueOf(NewOrder)+" WHERE item_order = "+String.valueOf(CurrentOrder);
    String sqlString2 = "UPDATE msr_summary_notices set item_order = "+String.valueOf(CurrentOrder)+" WHERE item_order = "+String.valueOf(NewOrder)+" AND absid <>"+rowid;
    statement1 = conn.prepareStatement(sqlString1);
    int RowsAffected1 = (statement1.executeUpdate());
    statement1.close();
    statement2 = conn.prepareStatement(sqlString2);
    int RowsAffected2 = (statement2.executeUpdate());
    statement2.close();
  }else{
    // Do nothing coz you can move down below MaxValue  

  }
}



if (submit.equals("Add Item")){

  if (mainHeading.equals("")){
     ErrorsDetected = true;
     ErrorList.add("Main Heading Can Not Be Blank");
  }

//  if (serviceName.equals("")){
//     ErrorsDetected = true;
//     ErrorList.add("Sub Topic Can Not Be Blank");
//  }

  if (description.equals("")){
      ErrorsDetected = true;
      ErrorList.add("Description Can Not Be Blank");
  }

  if  (!ErrorsDetected){

  sqlString = " INSERT INTO msr_summary_notices (year,month,topic,sub_topic,item,item_order) ";
  sqlString +=" VALUES ( ";
  sqlString += MSR_YEAR+",";
  sqlString += MSR_MONTH_NUMBER+",";
  sqlString += "'"+ mainHeading.replaceAll("'","''") +"',";
  sqlString += "'"+ serviceName.replaceAll("'","''") +"',";
  sqlString += "'"+ description.replaceAll("'","''") +"',";
  sqlString += String.valueOf(MaxValue+1);
  sqlString += ")";

  statement = conn.prepareStatement(sqlString);
  int RowsAffected = (statement.executeUpdate());
  statement.close();
  }

  action = "add";
//  mainHeading = "";
//  serviceName = "";
  description="";
} 

if (submit.equals("Update Item")){

  if (mainHeading.equals("")){
     ErrorsDetected = true;
     ErrorList.add("Main Heading Can Not Be Blank");
  }

//  if (serviceName.equals("")){
//     ErrorsDetected = true;
//     ErrorList.add("Sub Topic Can Not Be Blank");
//  }

  if (description.equals("")){
     ErrorsDetected = true;
     ErrorList.add("Number Can Not Be Blank");
  }

  if  (!ErrorsDetected){

          sqlString =  " UPDATE msr_summary_notices ";
      sqlString += " SET topic = '"+ mainHeading.replaceAll("'","''") +"',";
      sqlString += " sub_topic = '"+ serviceName.replaceAll("'","''") +"',";
      sqlString += " item = '"+ description.replaceAll("'","''") +"'";
      sqlString += " WHERE absid = "+rowid;

      statement = conn.prepareStatement(sqlString);
      int RowsAffected = (statement.executeUpdate());
      statement.close();
    }  
      action = "add";
      mainHeading = "";
      serviceName = "";
      description="";

} 

if (submit.equals("Delete Item")){
  sqlString =  " DELETE FROM msr_summary_notices ";
  sqlString += " WHERE absid = "+rowid;

  statement = conn.prepareStatement(sqlString);
  int RowsAffected = (statement.executeUpdate());
  statement.close();

  action = "add";
  mainHeading = "";
  serviceName = "";  
  description="";

}

if (cancel.equals("Cancel")){

  action = "add";
  mainHeading = "";
  serviceName = "";  
  description="";

} 


String absid = "";
String item = "";
String sub_topic = "";
String topic = "";
String item_order = "";

String item_no_hash = "";
String sub_topic_no_hash = "";

sqlString = "SELECT absid, topic, sub_topic, item ,item_order";
sqlString = sqlString + " FROM msr_summary_notices ";
sqlString = sqlString + " WHERE (year = "+MSR_YEAR+") AND (month ="+MSR_MONTH_NUMBER+") AND (topic NOT IN ('Notices','Services')) ";
sqlString = sqlString + " ORDER BY item_order ";

statement = conn.prepareStatement(sqlString);
resultset = statement.executeQuery();
resultsetHasData = resultset.next();

%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>G&Eacute;ANT Monthly Service Reports</title>
<meta http-equiv="content-type" content="text/html;charset=ISO-8859-1"/>

<!-- Template CSS -->
<link rel="stylesheet" type="text/css" href="./media/css/geant.css" />
<link rel="stylesheet" type="text/css" href="./media/css/ddaccordion.css" />
<link rel="stylesheet" type="text/css" href="./media/css/tweaks.css" />

<!-- Dynamic Drive Smooth Navigational Menu Script -->
<script type="text/javascript" src="./media/js/ddaccordion.js"></script>
<script type="text/javascript" src="./media/js/jquery-1.2.6.js"></script>
<script type="text/javascript" src="./media/js/jquery-1.3.2.js"></script>

<!-- start of sub menu  -->

<%@include file="includes/administration_submenu.jsp" %>

<!-- end of sub menu -->

<script type="text/javascript">

function showRow(RowId){

 var Row = document.getElementById("tr_"+RowId);
 Row.style.backgroundColor="#CCCCFF";

}
function hideRow(RowId){

     var Row = document.getElementById("tr_"+RowId);
     Row.style.backgroundColor="#FFFFFF";

}

function doDummy(id) {

<% if ((action.equals("move_up"))||(action.equals("move_down"))){ 
    out.println("showRow("+rowid+")");
}%>

<% if ((action.equals("edit"))||(action.equals("delete"))){ %>
<%    if (mainHeading.equals("Operations")){ %>
    document.forms["addNotices"].mainHeading.value = "Operations";
<%}%>
<%    if (mainHeading.equals("Future Plans")){%>
    document.forms["addNotices"].mainHeading.value = "Future Plans";
<%}%>
<%}%>


}

</script>

</head>

<body onLoad="doDummy(0)">
<div class='nineninefour whitebg'>

<!-- start of header  -->
    <%@include file="includes/header.jsp" %>
<!-- end of header  -->

<div class='clearboth weeny'>&nbsp;</div>

<div class='ninesevensix dottedline'>
    <div class='floatleft breadcrumbs'>
      <span><a href="home.jsp">MSR</a></span><span> &gt; </span><span>Administration</span><span> &gt; </span><span>Management Summary</span>
    </div>
    <div class='floatright breadcrumbs'>
      <script type="text/javascript" src="./media/js/datetime.js"></script>
    </div>
    <div class='clearboth weeny'>&nbsp;</div>
</div>

<div class='ninesevensix paddedtop'>


<!-- start of main menu  -->

<%@include file="includes/mainmenu.jsp" %>

<!-- end of main menu -->

<div class='seventhirty floatright'>
    <div class='floatleft seventwenty'>

        <div id="Main.text">
           <table width="720" border="0" cellspacing="0" cellpadding="0">
           <tr><td>
           <h3 class="blueblack nopad">Management Summary - <%=MSR_MONTH%> <%=MSR_YEAR%></h3>
           </td>
           <%@include file="includes/pagemenu_default.jsp" %>
           </tr>
           <tr><td colspan="2" class="hr_seventwenty maindottedline">&nbsp;</td></tr>
                   </table>

           <table width="720" border="0" cellspacing="5" cellpadding="0">
                   <form name="addNotices" action="ad_summary.jsp" method="post">
                   <input type="hidden" name="action" value="<%=action%>"/>
                   <input type="hidden" name="rowid" value="<%=rowid%>"/>

     <%
        /* Array to return any errors that may have been thrown at the top of the page */
        if (ErrorsDetected) {           
            for (int i=0; i< ErrorList.size(); i++){
                out.print("<tr bgcolor = '#FF6666'><td colspan='2' align='center'><strong>"+ErrorList.get(i)+"</strong></td></tr>");    
            }
        }  
        if (action.equals("delete")) {          
          out.print("<tr bgcolor = '#FFFF66'><td colspan='2' align='center'><strong>Are You Sure You Want To Delete This Record?</strong></td></tr>");  
        }  


     %>
       <tr>
         <td valign="top" width="150">Main Heading</td>
         <td>
         <select name="mainHeading" id="mainHeading">
            <option value="Operations">Operations</option>
            <option value="Future Plans">Future Plans</option>
         </select>
         </td>

       </tr>
       <tr>
         <td valign="top">Sub Topic</td>
         <td><input type="text" size="50" name="serviceName" id="serviceName" value="<%=serviceName%>" /></td>
       </tr>
       <tr>
         <td valign="top">Description</td>
         <td><textarea name="description" id="decription" rows="5" cols="68" ><%=description%></textarea></td>
       </tr>

       <tr>
<%     if (action.equals("edit")){%> 
        <td colspan="2" align="center"><input type="submit" name="submit" value="Update Item"></td>
<%     }%> 
<%     if (action.equals("delete")){%> 
        <td colspan="2" align="center"><input type="submit" name="submit" value="Delete Item">&nbsp;<input type="submit" name="cancel" value="Cancel"></td>
<%     }%> 
<%     if (action.equals("add")||action.equals("")){%> 
        <td colspan="2" align="center"><input type="submit" name="submit" value="Add Item"></td>
<%     }%> 
      </tr> 
      </form>
      </table>

      <table width="720" border="0" cellspacing="0" cellpadding="0">
      <tr><td>
      <h3 class="blueblack nopad">Current Management Summary - <%=MSR_MONTH%> <%=MSR_YEAR%></h3>
      </td>
      </tr>
      <tr><td class="hr_seventwenty maindottedline">&nbsp;</td></tr>
      </table>

 <% if (resultsetHasData) { %>     
       <table  class="datatable" width="720" border="0" cellspacing="0" cellpadding="0">
       <tr bgcolor="#BEDC00">
       <th class="tablepad thborder_bottom">Main Heading</th>
       <th class="tableborder_left_white">Sub Topic</th>
       <th class="tableborder_left_white">Description</th>
       <th colspan="4" class="tableborder_left_white">Actions</th>
       </tr>

   <%
     int RowCount = 0;
     while (resultsetHasData) {
       RowCount++;
       absid = resultset.getString("absid")!=null?resultset.getString("absid"):"";
       item = resultset.getString("item")!=null?resultset.getString("item"):"";
       sub_topic = resultset.getString("sub_topic")!=null?resultset.getString("sub_topic"):"";
       topic = resultset.getString("topic")!=null?resultset.getString("topic"):"";
       item_order = resultset.getString("item_order")!=null?resultset.getString("item_order"):"0";

       item_no_hash = UnHashIt(item);
       sub_topic_no_hash = UnHashIt(sub_topic);


// Convert Geant into E-acute version       
//       item = Eacute(item);
//       sub_topic = Eacute(sub_topic); 
//       topic = Eacute(topic); 
  %>
     <tr id="tr_<%=String.valueOf(RowCount)%>" onmouseover="showRow(<%=String.valueOf(RowCount)%>)" onmouseout="hideRow(<%=String.valueOf(RowCount)%>)">
     <td   class="tablepad tableborder_bottom" valign="top" width="200px">(<%=String.valueOf(RowCount)%>) <%=topic%></td>
     <td valign="top" width="200px" class="tableborder_left"><%=sub_topic%></td>
     <td valign="top" width="280px" class="tableborder_left"><%=item%></td>
     <td valign="top" class="tableborder_left"><a href="ad_summary.jsp?action=edit&rowid=<%=absid%>&description=<%=item_no_hash%>&serviceName=<%=sub_topic_no_hash%>&mainHeading=<%=topic%>" target="_top"><img src="./media/images/edit.jpeg" border="0"/></a></td>
     <td valign="top" class="tableborder_bottom"><a href="ad_summary.jsp?action=delete&rowid=<%=absid%>&description=<%=item_no_hash%>&serviceName=<%=sub_topic_no_hash%>&mainHeading=<%=topic%>" target="_top"><img src="./media/images/delete.jpeg" border="0"/></a></td>
     <td valign="top" class="tableborder_bottom"><a href="ad_summary.jsp?action=move_up&rowid=<%=absid%>&itemOrder=<%=item_order%>" target="_top"><img src="./media/images/16_arrow_up.png" border="0"/></a></td>
     <td valign="top" class="tableborder_bottom"><a href="ad_summary.jsp?action=move_down&rowid=<%=absid%>&itemOrder=<%=item_order%>" target="_top"><img src="./media/images/16_arrow_down.png" border="0"/></a></td></tr> 

 <% resultsetHasData = resultset.next();    } %>



     </table>
 <% } else { // endif resultset1HasData%>
 <p>There are no Management Summary Items for this period.</p>
 <% } %>

                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>
                <p>&nbsp;</p>

        </div>

        <h3 class='blueblack'>&nbsp;</h3>
    </div>

<!-- Right hand menu was here -->   

    <div class='clearboth weeny'>&nbsp;</div>
</div>
        <div class='clearboth weeny'>&nbsp;</div>   
    </div>
</div>

<!-- start of global footer  -->

<%@include file="includes/footer.jsp" %>

<!-- end of global footer  -->

</body>
</html>
<%
if (resultset != null) {
  try {
      resultset.close();
  }
  catch (SQLException e) {
       // Process Errors
  }
  resultset = null;
}   

if (statement != null) {
  try {
      statement.close();
  }
  catch (SQLException e) {
      // Process Errors
  }
  statement = null;
} 

if (conn != null) {
  try {
      conn.close();
  }
  catch (SQLException e) {
       // Process Errors
  }
  conn = null;
}   
%>
<%!
private String Eacute(String inputString){

    String convString = inputString;
    String replaceString = "";

    if (convString.indexOf("GEANT")!= -1){
      replaceString = "G&Eacute;ANT";
      convString = convString.replaceAll("GEANT",replaceString);
    }   

    if (convString.indexOf("Geant")!= -1){
      replaceString = "G&Eacute;ANT";
      convString = convString.replaceAll("Geant",replaceString);
    }

    if (convString.indexOf("geant")!= -1){
      replaceString = "G&Eacute;ANT";
      convString = convString.replaceAll("geant",replaceString);
    }

    if (convString.indexOf("GÉANT")!= -1){
      replaceString = "G&Eacute;ANT";
      convString = convString.replaceAll("GÉANT",replaceString);
    }   

    if (convString.indexOf("Géant")!= -1){
      replaceString = "G&Eacute;ANT";
      convString = convString.replaceAll("Géant",replaceString);
    }


    return convString;

}

private String UnHashIt(String inputString){
    String encodedValue = "";
    try{
        encodedValue = java.net.URLEncoder.encode(inputString, "iso-8859-1");
    } catch (Exception e) {
        //do something
    }
    return encodedValue;
}

private String HashIt(String inputString){

    String decodedValue = "";
    try{
        decodedValue = java.net.URLDecoder.decode(inputString, "iso-8859-1");
    } catch (Exception e) {
        //do something
    }
    return decodedValue;

}
%>

GÉ；蚂蚁每月服务报告
函数showRow（RowId）{
var Row=document.getElementById（“tr_”+RowId）；
Row.style.backgroundColor=“#CCCCFF”；
}
函数hideRow（RowId）{
var Row=document.getElementById（“tr_”+RowId）；
Row.style.backgroundColor=“#FFFFFF”；
}
函数doDummy（id）{
document.forms[“addNotices”].maintheading.value=“Operations”；
document.forms[“addNotices”].maintheading.value=“未来计划”；
}
行政管理摘要
管理摘要-
主标题
操作
未来计划
子主题
描述
当前管理摘要-
主标题
子主题
描述
行动
() 
此期间没有管理摘要项目

我主要关注“编辑”按钮

请参见下面的示例，其中包含2个屏幕截图

1-输入类型为“未来计划”，我点击“编辑”按钮

2-“主标题”默认为“操作”，尽管上面屏幕截图中的条目是“未来计划”。我希望这个“主标题”显示“未来计划”

试试这个：

替换：

  <select name="mainHeading" id="mainHeading">
            <option value="Operations">Operations</option>
            <option value="Future Plans">Future Plans</option>
  </select>

操作
未来计划

与：

未来计划
操作
操作
未来计划
操作
未来计划

删除doDummy函数，您将不再需要它。（同时将其从“已加载车身”标签中删除）

编辑：

好的，解决方案是这样做（仅使用javascript）：

//在正文底部编写脚本，根据当前选定的主标题值更改“选择”下拉列表。
//旧方法尝试将Scriptlet与javascript混合使用，但使用javascript更容易做到这一点。
const urlParams=新的URLSearchParams（window.location.search）；
const myParam=urlParams.get（'mainHeading'）；
//如果maintheading参数为null或等于GÉANT Operations，则显示GÉANT Operations下拉列表
if（myParam=='G|ANT Operations'| | myParam===null）{
document.getElementById（'maintheading'）。value='GÉANT Operations'；
}否则{
document.getElementById（'maintheading'）。value='GÉANT Future plan'；
}

您的确切意思是什么，操作是选择字段中的第一个选项，为什么它不总是默认为该选项？如果看不到更多的代码，就很难说为什么会出现这种行为。但从您所描述的内容和提供的代码来看，还不清楚。是的，“操作”是第一个选项。但是，如果一个条目是“未来计划”，并且您单击它旁边的“编辑”按钮，“主标题”列表值将默认返回“操作”，而不是显示最初输入的“未来计划”值。请参阅2屏幕快照，我可以根据您的javascript doDummy函数了解原因。您必须意识到jsp中的java在任何html/css/js之前运行。这个jsp页面是如何启动的？您是直接访问它还是一个servlet转发给它？是的，我是直接访问它OK，那么您在哪里声明

action

变量？请包含代码。此代码已删除下拉列表的内容。它现在是空的，没有任何选项。当你点击“运营”或“未来计划”时会怎么样？它加载了编辑字段，但列表仍然是空的：（非常感谢@Jonathan。问题解决了：）

  <select name="mainHeading" id="mainHeading">

<%if(mainHeading != null && mainHeading.equals("Future Plans")){%>
    <option value="Future Plans">Future Plans</option>
    <option value="Operations">Operations</option>
<%}%>

<%if(mainHeading != null && mainHeading.equals("Operations")){%>
    <option value="Operations">Operations</option>
    <option value="Future Plans">Future Plans</option>
<%}%>

<%if(mainHeading == null){%>
    <option value="Operations">Operations</option>
    <option value="Future Plans">Future Plans</option>
<%}%>

  </select>

<script>
//script at the bottom of the body to change select dropdown based on currently selected mainheading value.
//old method tried to use scriptlets mixed with javascript, but it's easier to do this with javascript.
const urlParams = new URLSearchParams(window.location.search);
const myParam = urlParams.get('mainHeading'); 
//if mainHeading parameter is null or equal to GÉANT Operations show GÉANT Operations dropdown
if(myParam === 'GÉANT Operations' || myParam === null) {
    document.getElementById('mainHeading').value = 'GÉANT Operations';
}else{
    document.getElementById('mainHeading').value = 'GÉANT Future Plans';
}
</script>