package com.yf.exam.core.utils;


import javax.servlet.http.HttpServletRequest;

/**
 * IP获取工具类，用户获取网络请求过来的真实IP
 * ClassName: IpUtils <br/>
 * date: 2018年2月13日 下午7:27:52 <br/>
 *
 * @author Bool
 * @version
 */
public class IpUtils {

	
	/**
	 *
	 * getClientIp:通过请求获取客户端的真实IP地址
	 * @author Bool
	 * @param request
	 * @return
	 */
	public static String extractClientIp(HttpServletRequest request) {

		String ip = null;

		//X-Forwarded-For：Squid 服务代理
		String ipAddresses = request.getHeader("X-Forwarded-For");

		if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
			//Proxy-Client-IP：apache 服务代理
			ipAddresses = request.getHeader("Proxy-Client-IP");
		}

		if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
			//WL-Proxy-Client-IP：weblogic 服务代理
			ipAddresses = request.getHeader("WL-Proxy-Client-IP");
		}

		if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
			//HTTP_CLIENT_IP：有些代理服务器
			ipAddresses = request.getHeader("HTTP_CLIENT_IP");
		}

		if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
			//X-Real-IP：nginx服务代理
			ipAddresses = request.getHeader("X-Real-IP");
		}

		//有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
		if (ipAddresses != null && ipAddresses.length() != 0) {
			ip = ipAddresses.split(",")[0];
		}

		//还是不能获取到，最后再通过request.getRemoteAddr();获取
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
			ip = request.getRemoteAddr();
		}

		return ip;
	}


}
