獲得客戶端的真實IP

public class IPUtil { 
    public static String getIpAddr(HttpServletRequest request) { 
        String ip = request.getHeader("X-Realader"X); 
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
    for" 
        } 
        if (ip == null || ip.length() == 0 || "unknown".equalsI . "); 
        } 
        if (ip == null || ip.length() == 0 || "unknown".equalsI )(ip -IP"); 
        } 
        if (ip == null || ip.length() == 0 || "unknown".equalsI pase(ip)) { (); 
        } 
        //以使用多重代理時回傳超過個ip。    ip= ip.substring(0,ip.indexOf( 「，」））； 
        } 
        回位提示； 
    } 
}