package city.albert.utils;

import javax.servlet.http.HttpServletRequest;

/**
 * @author niunafei
 * @function
 * @email [email protected]
 * @date 2020/8/31  5:02 PM
 */
public class IpUtils {
    /**
     * 獲取使用者真實IP地址，不使用request.getRemoteAddr()的原因是有可能使用者使用了代理軟體方式避免真實IP地址,
     * 可是，如果通過了多級反向代理的話，X-Forwarded-For的值並不止一個，而是一串IP值
     *
     * 
 
@return ip
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理後會有多個ip值，第一個ip才是真實ip
            if (ip.indexOf(",") != -1) {
                ip 
 
= ip.split(",")[0];
            }
        }
        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.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        System.out.println("獲取客戶端ip: " + ip);
        return ip;
    }
}