JSP script giving blank output on HPUX

Hi experts,

The follow code is generating a blank page while running from hp-ux (tomcat installed) :

--------------------------------------- CODE START ---------------------------------------------------------------

<%@ page language="java" import="java.io.*, java.util.*, java.lang.*" %>
<p>Testing Page</p>

<%
StringBuffer sb = new StringBuffer();

try
{
  String cmd = "ls";

  System.out.println ("Starting the process");
  Runtime runTime = Runtime.getRuntime();
  Process process = runTime.exec(cmd);
  InputStream inputStream = process.getInputStream();
  InputStreamReader   inputStreamReader = new InputStreamReader (inputStream);
  BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
  String line = null;
  while ( (line = bufferedReader.readLine()) != null ){
        sb.append(line); sb.append("\n");
  }
  System.out.println("Output : " + sb.toString());
  int exitVal = process.waitFor();
  System.out.println ("Process exitValue:  " + exitVal );
}catch (Throwable t)
{
  t.printStackTrace();
}

%>

----------------------------------------------------- CODE END --------------------------------------------------

----------------------------------------------------- OUTPUT START --------------------------------------------

Testing Page

------------------------------------------------------ OUTPUT END -----------------------------------------------


Any help?

Thanks in advance.