java获取客户端的ip地址

/**
     * 获取客户端IP地址
     * @param request
     * @return
     */
    public String getIpAddr(HttpServletRequest request){
        String ip = request.getHeader("x-forwarded-for");
        if(ip == null || ip.length() < 1
                || "unknown".equalsIgnoreCase(ip)){
            ip = request.getHeader("Proxy-Client-IP");
        }
        if(ip == null || ip.length() < 1
                || "unknown".equalsIgnoreCase(ip)){
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if(ip == null || ip.length() < 1
                || "unknown".equalsIgnoreCase(ip)){
            ip = request.getRemoteAddr();
        }
        return ip;
    }