You will need to make a socket connection to the servlet and then parse the servlet response.
Try Using something like this:
$domain = "123.123.123.123"; //whatever
$srvlet_msg = "?keyname=keyvalue";
$fp = fsockopen ("$domain", 80, &$errno, &$errstr, 30);
if (!$fp) { echo "ERROR: $errstr ($errno)<br>\n"; }
else {
fputs ($fp, "POST /servlet/servletname$srvlet_msg HTTP/1.0\n\n");
while (!feof($fp)) { $FileContents .= fgets ($fp,4096); }
fclose ($fp);
}
//servlet response should be in the $FileContents scalar
Read the documentation for fsock* at php.net
Hope this helps