获取请求ip地址

public String checkIpAddress(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;

 }