Java无法获取真实IP解决方案

public static String getRealIp(HttpServletRequest request) {
	String ip = request.getHeader("x-forwarded-for");
	String unknown = "unknown";
	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.getRemoteAddr();
	}
	return ip;
}

location ^~ /api {
  proxy_pass http://127.0.0.1:8110/;
  proxy_read_timeout 90;
  #得到请求真实IP
  proxy_set_header  X-Real-IP    $remote_addr;
  proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header  HTTP_X_FORWARDED_FOR $remote_addr;
  proxy_set_header  X-Forwarded-Proto $scheme;
  proxy_redirect   default;

}