com.ibm.jsse2.util.h: No trusted certificate found error

I've a small web-app that is deployed and run in the websphere 6.1 app
server. This app has this simple piece of code:

HttpURLConnection conn = null;
try {
HttpURLConnection.setFollowRedirects(false);
conn = (HttpURLConnection) new
URL(redirect.getRedirectToURL()).openConnection();
conn.setRequestMethod("HEAD");
if (conn.getResponseCode() >= 400) {
throw new RedirectException("The Redirect-To URL (" +
redirect.getRedirectToURL() + ") is invalid.");
}
}
catch (RedirectException ex){
throw ex;
}
catch (Exception ex){
throw new RedirectException("The Redirect-To URL (" +
redirect.getRedirectToURL() + ") is invalid.");
}
finally {
if (conn != null) conn.disconnect();
}


On the fourth line where it performs the connection, it works fine if
the url is a http. But it failed if the url is a https. The error that
I'm getting is "com.ibm.jsse2.util.h: No trusted certificate found". If
I run above code as a stand alone java program, it works fine for http
and https. Does anyone know why or how I can avoid this error?