package com.dashan.utils.iputils;

import org.apache.commons.lang.StringUtils;
import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * @author ADMIN
 */
public class IPNWUtil {

    public static String findNWIp(HttpServletRequest request) {
        String ipAddress = null;
        ipAddress = request.getHeader("x-forwarded-for");
        if (StringUtils.isEmpty(ipAddress) || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(ipAddress) || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isEmpty(ipAddress) || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("HTTP_CLIENT_IP");
        }
        if (StringUtils.isEmpty(ipAddress) || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
            if (ipAddress.equals("127.0.0.1")) {
                // 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;
    }
    
}