Could this unclosed() byteArrayInputStream cause high Heap usage ?

Hi all,

As part of our reporting integrated with our JSF/JSP application, the
report is converted to PDF then sent to browser for user to display.
mean while during peak load our Heap usage could reach 3.5GB - 4GB. So
I am suspecting the unclosed byteArrayInputStream is the cause.
(This is a production application so I am collecting information
before change the code)

Is the unclosed() byteArrayInputStream really cause the problem ?
(the codes is below)

Thank you,
Krist

ByteArrayInputStream byteArrayInputStream = (ByteArrayInputStream)
 
reportClientDoc.getPrintOutputController().export(exportOptions);
reportClientDoc.close();
writeToBrowser(byteArrayInputStream, response, "application/csv",
EXPORT_FILE);

private void writeToBrowser(ByteArrayInputStream byteArrayInputStream,
HttpServletResponse
response, String mimetype, String exportFile)
   throws Exception {
      byte[] buffer = new byte[byteArrayInputStream.available()];
      int bytesRead = 0;
      response.reset();
      response.setHeader("Content-disposition", "inline;filename=" +
exportFile);
      response.setContentType(mimetype);
      //Stream the byte array to the client.
      while((bytesRead = byteArrayInputStream.read(buffer)) != -1)
            { response.getOutputStream().write(buffer , 0,
bytesRead);}

      //Flush and close the output stream.
      response.getOutputStream().flush();
      response.getOutputStream().close();
   }