获取访问者 IP

    /**
     * 获取经过代理服务器的访问者IP
     *
     * @return IP地址
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

    /**
     * 获取未经过代理服务器的访问者IP
     * @return IP地址
     */
    public static String ipAddr(HttpServletRequest request) {
        return request.getRemoteAddr();
    }