在java中獲取客戶端真實的IP地址

1. public static String getRemoteAddress(HttpServletRequest request){   
2.     String ip = request.getHeader("x-forwarded-for");   
3.     if(ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) ip = request.getHeader("Proxy-Client-IP");   
4.     if(ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) ip = request.getHeader("WL-Proxy-Client-IP");   
5.     if(ip == null || ip.length() == 0 || ip.equalsIgnoreCase("unknown")) ip = request.getRemoteAddr();   
6.     return ip;   
7. }