獲取請求IP地址

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