java获取IP

public String getIpAddress(HttpServletRequest request){
        String ip = request.getHeader("x-forwarded-for");
        if(ip==null||ip.length()==0||"unknown".equalsIgnoreCase(ip)){        //忽略大小写
            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;
    }