apache作反向代理，向後端轉發客戶端真實IP

一、依賴模塊

    LoadModule remoteip_module modules/mod_remoteip.so

二、http.conf添加配置

    RemoteIPHeader x-forwarded-for
    RemoteIPInternalProxy 127.0.0.1

三、代碼

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.getRemoteAddr();
}