How I could copy one response to another by httpClient

I trtied to copy content of one response to another but still failed:

 private void makeACall(String url, String oldUrl,  HttpServletResponse res) throws ClientProtocolException, IOException
 {
  HttpGet httpget = new HttpGet(url);
     byte[] b = null;
  CloseableHttpClient httpclient = HttpClients.createDefault();
  CloseableHttpResponse response = httpclient.execute(httpget);
  try {
      HttpEntity entity = response.getEntity();
      if (entity != null) {
          InputStream in = entity.getContent();
             PrintWriter writer = res.getWriter();
          try {
              // read remote host respponse
     // copy from one response to another one
           
           ByteArrayOutputStream out = new ByteArrayOutputStream();
           byte[] buffer = new byte[1024];
           while (true) {
               int r = in.read(buffer);
               if (r == -1) break;
               out.write(buffer, 0, r);
           }

           byte[] ret = out.toByteArray();
           
           out.write(buffer);
           out.flush();
           out.close();
     
     // populate local host response

               writer.print(new String(ret));
         res.setStatus(HttpServletResponse.SC_CREATED);
      res.setContentLength(ret.length);
         res.setContentType("text/json");
         res.setHeader("Location", oldUrl);
             
           res.setHeader("Access-Control-Allow-Origin", oldUrl);
           res.setHeader("Content-Type", "application/json");
           
          } finally {

              writer.flush();
              writer.close();
              in.close();
          }
      }
  } finally {
      response.close();
  }
 }