// java 後臺獲取訪問客戶端ip地址 

 protected String getClientIpAddress(HttpServletRequest request) {  
            String clientIp = request.getHeader("x-forwarded-for");  
            if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {  
                clientIp = request.getHeader("Proxy-Client-IP");  
            }  
            if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {  
                clientIp = request.getHeader("WL-Proxy-Client-IP");  
            }  
            if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {  
                clientIp = request.getRemoteAddr();  
            }  
            return clientIp;  
        }