Mixing scriplets within droplets question? newbie question

Question

All,
I am trying to retrieve data from a droplet and store it in csv format. For this purpose, i am planning to use a stringBuilder, iterate the data returned using for each and append this string builder. At the end of the code i am planning to use scriplet to read this string buffer. Below is my code.
First issue is : As soon as i add scriplet within <dsp:getvalueof> tag my page stops working
Second issue : So you think scriplet at the end of code is correct?
Thanks in advance
Any help on topic will be appreciated.
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
<%@ taglib uri="dsp" prefix="dsp" %>
<%@ page import="java.io.FileInputStream" %>
<%@ page import="java.io.BufferedInputStream" %>
<%@ page import="java.io.File" %>
<%@ page import="java.io.IOException" %>
<%@ page import="java.util.List" %>
<%@ page import="java.net.URLConnection" %>
<%@ page import="java.io.BufferedOutputStream" %>
<%@ page import="java.util.zip.ZipOutputStream" %>
<%@ page import="java.io.FileOutputStream" %>
<%@ page import="java.util.zip.ZipEntry" %>
<dsp:page>
<dsp:importbean bean="/xyz/droplet/NikeProductsDroplet"/>
<dsp:importbean bean="/xyz/core/util/ProductCatalogUrlBuilderDroplet"/>
<%
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition","attachment;filename=temp.csv");
String testVar ="" ;
StringBuffer writer = new StringBuffer();
     writer.append("DisplayName");
     writer.append('\n');
%>
     <dsp:droplet name="ABCProductsDroplet">
          <dsp:oparam name="output">
DisplayName, Part Number, Vendor Name, URL
               <dsp:droplet name="/atg/dynamo/droplet/ForEach">
                    <dsp:param name="array" param="allProducts" />
                    <dsp:oparam name="output">
<dsp:getvalueof id="displayNameTest" param="element.displayName" idtype="java.lang.String">
<%
testVar = displayNameTest;
writer.append(testVar);
writer.append('\n');
%>
</dsp:getvalueof>
</dsp:oparam>
</dsp:droplet>
</dsp:oparam>
</dsp:droplet>
<%
     ServletOutputStream out = response.getOutputStream();
     InputStream in = new ByteArrayInputStream(writer.toString().getBytes("UTF-8"));
byte[] outputByte = new byte[4096];
          while(in.read(outputByte, 0, 4096) != -1)
               out.write(outputByte, 0, 4096);
          in.close();
          out.flush();
          out.close();
     %>
</dsp:page>

Answer 1

First issue is : As soon as i add scriplet within <dsp:getvalueof> tag my page stops working
You must be getting some error in console.Please post that error.
directly use :
<dsp:getvalueof id="displayNameTest" param="element.displayName" idtype="java.lang.String">
<%
writer.append(displayNameTest);
writer.append('\n');
%>
</dsp:getvalueof>