java获取客户端ip

java获取客户端ip

　　Java获取IP地址:如果使用了反向代理软件，request.getRemoteAddr()获取到的是代理的ip，并不是客户端的ip。

　　经过代理以后，由于在客户端和服务之间增加了中间层，因此服务器无法直接拿到客户端的IP，服务器端应用

　　也无法直接通过转发请求的地址返回给客户端。但是在转发请求的HTTP头信息中，增加了X－FORWARDED－FOR

　　信息用以跟踪原有的客户端IP地址和原来客户端请求的服务器地址。

 /**
     * 获取请求ip地址
     * @param request
     * @return
     */
    public static String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            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.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        // 如果是多级代理，那么取第一个ip为客户ip
        /*if (ip != null && ip.indexOf(",") != -1) {
            ip = ip.substring(ip.lastIndexOf(",") + 1, ip.length()).trim();
        }*/
        return ip;
    }