java 獲取web登錄者的ip地址

/**
     * 獲取訪問用戶的客戶端IP（適用於公網與局域網）.
     */
    public static final String getIpAddr(final HttpServletRequest request)
            throws Exception {
        if (request == null) {
            throw (new Exception("getIpAddr method HttpServletRequest Object is null"));
        }
        String ipString = request.getHeader("x-forwarded-for");
        if (StringUtils.isBlank(ipString) || "unknown".equalsIgnoreCase(ipString)) {
            ipString = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isBlank(ipString) || "unknown".equalsIgnoreCase(ipString)) {
            ipString = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isBlank(ipString) || "unknown".equalsIgnoreCase(ipString)) {
            ipString = request.getRemoteAddr();
        }
     
        // 多個路由時，取第一個非unknown的ip
        final String[] arr = ipString.split(",");
        for (final String str : arr) {
            if (!"unknown".equalsIgnoreCase(str)) {
                ipString = str;
                break;
            }
        }
     
        return ipString;
    }