获取客户端IP地址

import javax.servlet.http.HttpServletRequest;

/**
 * 获取客户端IP地址
 * @author lizhangyu
 * @Date 2019-11-15
 */
public class IpUtils {

	/**
	 * IP请求头候选列
	 */
    private static final String[] IP_HEADER_CANDIDATES = {
            "X-Forwarded-For",
            "Proxy-Client-IP",
            "WL-Proxy-Client-IP",
            "HTTP_X_FORWARDED_FOR",
            "HTTP_X_FORWARDED",
            "HTTP_X_CLUSTER_CLIENT_IP",
            "HTTP_CLIENT_IP",
            "HTTP_FORWARDED_FOR",
            "HTTP_FORWARDED",
            "HTTP_VIA",
            "REMOTE_ADDR"
    };

    /**
     * 获取客户端IP地址
     * @param request HttpServletRequest 请求对象
     * @return 客户端IP
     */
    public static String getClientIp(HttpServletRequest request) {
        for (String header : IP_HEADER_CANDIDATES) {
            String ip = request.getHeader(header);
            if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
                return ip;
            }
        }
        return request.getRemoteAddr();
    }
}