public String getIpAddress(HttpServletRequest request) {
    String ipAddress = request.getHeader("x-forwarded-for");
    if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("Proxy-Client-IP");
    }
    if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("WL-Proxy-Client-IP");
    }
    if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getRemoteAddr();
        if(ipAddress.equals("127.0.0.1") || ipAddress.equals("0:0:0:0:0:0:0:1")){
            //根据网卡取本机配置的IP  
            InetAddress inet=null;
            try {
                inet = InetAddress.getLocalHost();
            } catch (UnknownHostException e) {
                e.printStackTrace();
            }
            ipAddress= inet.getHostAddress();
        }
    }
    //对于通过多个代理的情况,第一个IP为客户端真实IP,多个IP按照‘,‘分割  
    if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15  
        if(ipAddress.indexOf(",")>0){
            ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
        }
    }
    return ipAddress;
}原文:https://www.cnblogs.com/syscn/p/12156560.html