java获取登录用户ip地址

您可以使用Java的Servlet API中的request对象获取登录用户的IP地址，具体代码如下：

String ipAddress = request.getHeader("X-Forwarded-For");
if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
    ipAddress = request.getHeader("Proxy-Client-IP");
}
if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
    ipAddress = request.getHeader("WL-Proxy-Client-IP");
}
if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
    ipAddress = request.getHeader("HTTP_CLIENT_IP");
}
if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
    ipAddress = request.getHeader("HTTP_X_FORWARDED_FOR");
}
if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
    ipAddress = request.getRemoteAddr();
}

请注意，这种方法可能无法100%准确地获取用户的IP地址，因为某些代理服务器可能会修改X-Forwarded-For头部信息。但一般情况下，该方法可以较为准确地获取用户的IP地址。