Get requestor ip

HttpServletRequestUtil.java

import javax.servlet.http.HttpServletRequest;

public class RequestUtil {

  public static String getRequestIp(final HttpServletRequest request) {
    String ip = request.getHeader("X-Forwarded-For");
    if (ip == null) {
      return request.getRemoteAddr();
    }
    ip = ip.trim();
    final int multipleIpsIndex = ip.lastIndexOf(',');
    if (multipleIpsIndex > 0) {
      ip = ip.substring(multipleIpsIndex + 1);
    }
    return ip.isEmpty() ? request.getRemoteAddr() : ip;
  }
}