JAVA取得IP

一般這樣取一個IP：request.getRemoteAddr(),但有時候取出來的是不對的，特別是在應用前加了Nginx之類的軟件，下面的方法能夠取出訪問的IP地址

public static String getRemoteAddrIp(HttpServletRequest request) {
        String ipFromNginx = getHeader(request, "X-Real-IP");
        //System.out.println("ipFromNginx:" + ipFromNginx);
        //System.out.println("getRemoteAddr:" + request.getRemoteAddr());
        return StringUtils.isEmpty(ipFromNginx) ? request.getRemoteAddr() : ipFromNginx;
    }
    private static String getHeader(HttpServletRequest request, String headName) {
        String value = request.getHeader(headName);
        return !StringUtils.isBlank(value) && !"unknown".equalsIgnoreCase(value) ? value : "";
    }