Simple way to do a facebook like check in java

People are making this so hard.  Now facebook is moving from fbml you gotta do the like check yourself instead of using the very convenient . Here is my simple solution after 3 hours of trying the hard versions.

static final Pattern FB_SIGNED_REQUEST_PATTERN = Pattern.compile("liked\":(.)");
static final BASE64Decoder BASE64_DECODER = new BASE64Decoder();
public static boolean isFacebookFan(HttpServletRequest request)
throws Exception
{
String fbreq = request.getParameter("signed_request");
if (fbreq == null) throw new Exception("No request");
fbreq = new String(BASE64_DECODER.decodeBuffer(fbreq));
log.error(fbreq);
Matcher m = FB_SIGNED_REQUEST_PATTERN.matcher(fbreq);
return m.find() && m.group(1).equals("t");
}