Android : Android: how to measure the loopback traffic amount of each app

I have developed an app to manage the amount of traffic. I'm using the TrafficStats API. getUidRx/TxBytes() returns traffic amount includes the loopback traffic. But, information of loopback traffic is not required.

So, I have examined the method of measuring the loopback traffic amount for each app.

Information of the traffic amount in the following file.

/proc/net/xt_qtaguid/stats

However, it is not possible to read from my app.

[Reference] read /proc/net/xt_qtaguid/stats in my user application and caused java.lang.nullpointerexception

I can get total loopback traffic amount.

Method getRxBytesMethod = TrafficStats.class
        .getDeclaredMethod("getRxBytes", new Class[]{String.class});
long loopbackRxBytes = (Long) getRxBytesMethod.invoke(null, "lo");

Is it possible to know the uid that is currently communication?