JAVA获取客户端请求的当前网络ip地址（附：Nginx反向代理后获取客户端请求的真实IP）

1. JAVA获取客户端请求的当前网络ip地址：

    /**
     * 获取客户端请求的当前网络ip
     * @param request
     * @return
     */
    public static String getIpAddr(HttpServletRequest request){
        String ipAddress = request.getHeader("X-Real-IP");//先从nginx自定义配置获取
        if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            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;
    }

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2. Nginx反向代理后获取客户端请求的真实IP

在nginx.conf配置文件中，配置：

proxy_set_header X-Real-IP           $remote_addr;

例如：

location /服务名称 {
     proxy_set_header X-Real-IP           $remote_addr;
     proxy_pass  http://xaserver/服务名称;
     client_max_body_size  1000m;
}