java 获取客户端ip地址

/**
  *
  * 功能说明：获取IP地址
  * 参数及返回值:
  * @param request
  * @return
  */
 public static String getClientIP(HttpServletRequest request) {
  String ip = request.getHeader("x-forwarded-for");
  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.getRemoteAddr();
  }
  return ip;
 }