How can I get source name from JSP file AND make it to img src?

Question

I'm making Online bookstore ShoppingMall with MVC not Spring.

I got DAO file and Servlet file and JSP file. ProductRegisterAction.java(servelt) / ProductDAO.java / productRegister.jsp

I want to register image but I have problem. My images are in folder '/images/CATEGORYNAME/' (not CATEGORYNAME, humanities, and so etc. See image please)

Anyway, I got CATEGORYNAME from JSP file form with select option. how can i give this values to Servlet file?

This is servlet file.

CategoryVO catevo = new CategoryVO();
String cate_name = mtrequest.getParameter("cate_name");
catevo.setCate_name(cate_name);
cate_name = mtrequest.getParameter("cate_name");
                            
ServletContext svlCtx = session.getServletContext();
String uploadFileDir = svlCtx.getRealPath("/images/product"+cate_name);

And this is JSP file.

<form name="prodInputFrm"
      action="<%= request.getContextPath()%>/product/admin/productRegister.book"
      method="POST"
      enctype="multipart/form-data">
<table id="tblProdInput" style="width: 80%;">

...
<tr>
 <td width="25%" class="prodInputName" style="padding-top: 10px;">CATEGORY</td>
 <td width="75%" align="left" style="padding-top: 10px;">
  <select name="fk_cate_num" class="infoData">
    <option value="">SELECT CATEGORY</option>
     <c:forEach var="map" items="${requestScope.categoryList}">
       <option value="${map.pk_cate_num}">${map.cate_name}</option>
     </c:forEach>
  </select>
 </td>
</tr>