判斷請求是不是同一個域名

// 判斷是否同個域名
    public static boolean validate(HttpServletRequest request) {
        String Referer = "";
        boolean referer_sign = true; // true 站內提交，驗證經過 //false 站外提交，驗證失敗
        Enumeration headerValues = request.getHeaders("Referer");
        while (headerValues.hasMoreElements())
            Referer = (String) headerValues.nextElement();
        // 判斷是否存在請求頁面
        if (Referer == null || Referer.length() < 1)
            referer_sign = false;
        else {
            // 判斷請求頁面和getRequestURI是否相同
            String servername_str = request.getServerName();
            if (servername_str != null || servername_str.length() > 0) {
                int index = 0;
                if (Referer.indexOf("https://") == 0) {
                    index = 8;
                } else if (Referer.indexOf("http://") == 0) {
                    index = 7;
                }
                if (Referer.length() - index < servername_str.length()) // 長度不夠
                    referer_sign = false;
                else { // 比較字符串（主機名稱）是否相同
                    String referer_str = Referer.substring(index, index + servername_str.length());
                    if (!servername_str.equalsIgnoreCase(referer_str))
                        referer_sign = false;
                }
            } else
                referer_sign = false;
        }
        return referer_sign;
    }