src/main/java/org/jivesoftware/smack/util/StringUtils.java
public static boolean isFullJID(String jid) {
        if (parseName(jid).length() <= 0 || parseServer(jid).length() <= 0
                || parseResource(jid).length() <= 0) {
            return false;
        }
        return true;
    }
public static boolean isFullJID(String jid) {
        if (parseName(jid).length() <= 0 || parseServer(jid).length() <= 0
                || parseResource(jid).length() <= 0) {
            return false;
        }
        return true;
    }
Returns true if jid is a full JID (i.e. a JID with resource part).

@param jid
@return true if full JID, false otherwise