如下， 到了
<form name="modelForm" action="/portal/defectinfo/toDefectPage?projectname=<%=request.getAttribute("projectname")%>" method="post" theme="simple">
<select id="codeid" name="codeid" headerKey="0" onChange="modelForm.submit()" style="padding-left:5px; vertical-align:middle; font-size:14px;border-radius:5px; 160px;height:33px">
<c:forEach items= "${mapcode}" var="c">
<option value="${c.key}">${c.value}</option>
</c:forEach>
</select>
</form>