class SQLUtils {

    public static SQLDriver getDriver(String prefix) {
        for (SQLDriver driver : Lookup.getDefault().lookupAll(SQLDriver.class)) {
            if (driver.getPrefix().equalsIgnoreCase(prefix)) {
                return driver;
            }
        }
        return null;
    }

    public static String getUrl(SQLDriver driver, String host, int port, String dbname) {<FILL_FUNCTION_BODY>}
}

        String res = "jdbc:";
        res += driver != null ? driver.getPrefix() : "";
        res += "://";
        res += host != null ? host : "";
        res += ":";
        res += port != 0 ? port : "";
        res += dbname != null ? "/" + dbname : "";
        return res;
    
<no_super_class>