检查URL是否ping通

/**
     * 检查URL是否ping通
     *
     * @Title: existsIsUrl
     * @Description:
     * @return boolean
     * @throws
     * @param URLName
     * @return 2013-11-1
     */
    private boolean existsIsTrue(String s) {
        boolean temp = false;
        URL url;
        try {
            url = new URL(s);
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            int state = con.getResponseCode();
            if (state == 200) {
                temp = true;
            } else {
                temp = false;
            }
        } catch (Exception e1) {
            url = null;
            return temp;
        }
        return temp;
    }